Evaluation Methods
A method for the rapid
quantification of anti-plaque
activity in vitro
Ritchie JA, Jones CL and
Prottey C
J Dent Res 1987, 66 (special issue),
859
Distal mesial plaque index: A
technique for assessing dental
plaque about the gingiva
Fischman S, Cancro LP,
Pretara-Spanedda P and
Jacobs D
Dental Hygiene 1987, 61,
404-409
The choice of an index system for
clinical testing is usually made in
consideration of the objectives of
the trial, size of the population,
period of the study and the type
and extent of change anticipated.
The objective of this study was to
evaluate a newly developed index
called the Distal Mesial Plaque
Index (DMPI) for sensitivity to
changing plaque state compared to
the established Modified Navy
Plaque Index (MN). The DMPI was
developed to reflect changes about
the proximal surfaces of the
gingival margin and this study
demonstrated a high correlation to
the MN. Correlations of the
total plaque scores to the total
weight of plaque removed was
appreciably higher for the DMPI
than the MN.
Periodontal awareness project
in the United Kingdom: CPITN
and self-assessment
Chesters RK, Dexter CH, Life JS,
Smales FC and van der Ouderaa F
Int Dent J 1987, 37, 218-221
CPITN score for each sextant was
used to determine treatment needs
for comparison with those
diagnosed by the specialist
periodontologists. The preliminary
results of this study are summarised
in Table 111. The four columns on
the left of Table 111 indicate the
percentage agreement between
the five experts for all these
activities, involving sponsored
research at a dental school and a
study with UK dentists, have
shown the potential of CPITN as a
screening method for patients in
general practice for periodontal
diseases. There is evidence to show
that patient-orientated
programmes have increased
periodontal awareness in the UK.
Development of a Rapid Human
Calculus Screening Model
Frienberg CA, Fernandez PM,
Lesetz M and Kanapka J
J Dent Res 1991, 70, 326
An In Vitro Plaque
Mineralisation Model for
Assessing Anti-calculus Agents
Bajor JS, Viccaro JP and Kanapka J
J Dent Res 1991, 70, 326
Comparison of Invasive and
Non-invasive Indices for
Gingivitis Measurement
Saxton CA, Putt MS* and
Soparker PM**
(*Department of Chemistry,
Indiana-Purdue University, Fort
Wayne, Indiana, USA)
(**Forsyth Dental Centre, Boston,
Massachusetts, USA)
J Dent Res 1991, 71, 327
A modified chemostat system to
study the ecology of oral
biofilms
Bradshaw DJ*, Marsh PD*, Watson
GK and Cummins D
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
J Dent Res 1992, 71, 674
A Biofilm model system which
simulates dental plaque
Bosko CA, Bajor J, Carson Rand
Schilling K
J Dent Res 1992, 71, 734
iIMAGEM 1
IMAGEM2
The use of CLSM for the study
of mixed plaque
Moss MC, Jones CL, Cummins D
and Howard CV*
(*Department of Human Anatomy
and Cell Biology, University of
Liverpool, Liverpool, UK)
J Dent Res 1992, 71, 601
Applications of confocal laser
scanning microscopy in in situ
mapping
Moss MC, Veiro JA, Singleton S,
Gregory DP, Birmingham JJ, Jones
CL, Cummins PG, Cummins D,
Miller RM, Sheppard RC*, Howard
VC** and Bhasker N*** (*Medical
Research Council, Laboratory of
Molecular Biology, Cambridge, UK)
(**Department of Human Anatomy
and Cell Biology, University of
Liverpool, Liverpool, UK)
(***Phase Separations Limited,
Deeside, Clwyd, UK)
Analyst 1993, 118, 1-9
A confocal laser scanning
microscope has been applied to the
detailed study of non-invasive
mapping on targeted systems. This
paper aims to show, by particular
reference to specific problems, the
wide ranging potential of the
technique for the analytical
community. The specific problems
successfully tackled by the
technique include characterization
of two types of inert support
bodies and the precursor/enzyme
distributions therein, the effect of
processing on dye penetration in
fibres, mapping the
interdependence and growth
patterns in bacterial and noninvasive
examination of epidermal
tissue layers.
Validation of a 21-day partial
mouth gingivitis model for
evaluating chemotherapeutic
dentifrices
Putt M*, van der Weijden**,
Kleber CJ* and Saxton CA
(*Health Science Research, Indiana
University-Purdue University, Fort
Wayne, USA
**Department of Periodontology,
Academic Centre for Dentistry,
Amsterdam, The Netherlands)
J Periodontal Res 1993, 28,
301-307
The experimental gingivitis model
has long been used to evaluate
chemotherapeutic agents in
mouthrinses. Only recently
however, has the model been
modified to test undiluted
dentifrices by using a toothshield
both to apply dentifrice and to
protect selected teeth from
toothbrushing. This also enables
participants to brush the rest of the
mouth and avoid the
unpleasantness of three weeks
without oral hygiene. Because of
its well-documented efficacy,
chlorhexidine was used in a
toothpaste formulation to
investigate the validity of the
partial-mouth, experimental
gingivitis model for evaluating
therapeutic dentifrices. Optimal
gingival health was established in
88 adults, who then were
randomly assigned to two equal
groups. A toothshield was
constructed for each subject to fit
the teeth of one mandibular
quadrant. During the trial
chlorhexidine or placebo dentifrice
was applied undiluted to the test
teeth via the toothshield, which
also prevented plaque removal
during brushing of the remaining
dentition. After 21 days, plaque
and gingivitis had developed in
both groups. However, the
chlorhexidine group had
significantly less plaque and
gingivitis than the placebo group.
No adverse soft tissue effects were
observed. This study demonstrated
that the partial-mouth,
experimental gingivitis model
allowed unhindered development
of plaque and gingivitis that was
comparable to whole-mouth
studies in which oral hygiene was
suspended for three weeks. By
corroborating with chlorhexidine, it
is concluded that this short-term
clinical model is valid for evaluating
the chemotherapeutic effect of
dentifrices.
A microassay for bacterial
adherence to hydroxyapatite
Schilling KM, Carson RG, Bosko
CA, Golikeri GD, Bruinooge A,
Hoyberg K, Waller AM and
Hughes NP
Colloids and Surfaces B:
Biointerfaces 1994, 3, 31-38
The aim of the present study was
to develop a microassay for
bacterial adherence to
hydroxyapatite (HA) which is more
convenient, reduces the required
amounts of materials, and removes
artifactual tube “wall effects”. To
form HA in situ on 96-well plates,
the wells were filled with 2.5mmol
1-1 calcium chloride, 7.5mmol 1-1
potassium phosphate, 250mmol 1-
1 triethanolamine (pH 7.4) and the
plates were incubated for 1.5h at
75°C. The solution was decanted
and the entire procedure was
repeated three more times. Analysis
of the mineral composition showed
the Ca/P ratio to be 1.63. X-ray
and electron diffraction analyses
indicated that all the mineral
formed was HA. Scanning electron
microscopy showed a continuous
layer of HA crystallites with
occasional aggregates and no
exposed polystyrene. Salivary
pellicles were formed on the HA
surfaces either with or without the
in situ synthesis of glucans. The
pellicle-coated HA plates were
incubated with radiolabelled
bacteria for 1.0h at 37°C.
Adherent bacteria were digested
with 1mmol 1-1 EDTA/1 N NaOH
for 1.0h at 37°C and were
quantitated by scintillation
counting. The results showed that
the Streptococcus gordinii,
Actinomyces naeslundii
(Actinomyces viscosus), and
Streptococcus mutans bound to HA
plates coated with saliva or saliva
plus glucans in a stereospecific
manner. The relative levels of
bacteria which attached to HA
plates paralleled the results found
with spheroidal whitlockite beads.
The HA plates eliminate wall
effects, simplify sample processing
and scintillation counting, require
smaller amounts of reagents, and
reduce radioactive and other
waste. Accordingly, HA-coated
microtitre plates represent an
improved format for studying oral
bacterial adhesion.
IMAGEM 3
Intra/inter examiner
reproducibility study of gingival
bleeding
van der Weijden GA*, Timmerman
MF*, Saxton CA, Russell JI,
Huntington E and
van der Velden U*
(*Department of Periodontology,
ACTA, Academic Centre for
Dentistry, Amsterdam, The
Netherlands)
J Periodontal 1994, 29, 236-241
Sulcular bleeding after stimulation
with a periodontal probe has been
associated with the presence of an
inflammatory lesion in the gingiva.
The objective of this study was to
evaluate the effect of the
placement of the probe in relation
to the tooth surface, and the effect
of standardising the probing
pressure on the intra- and interexaminer
reproducibility of the
gingival bleeding when using a
well-defined bleeding index. Four
different variations were defined:
parallel bleeding index (ParBI):
when the probe is run along the
marginal gingiva it is held parallel
to the tooth surface. Angulated
bleeding index (AngBI): the probe is
held at an angle of approximately
60° to the longitudinal axis of the
tooth and in contact with the
sulcular epithelium. Controlled
force parallel bleeding index (CFParBI)/
controlled force angulated
bleeding index (CF-AngBI): the
same procedure as described for
the Par BI and AngBI is followed,
but instead of a conventional
(WHO-ASH/Dentsply®) probe an
adjustable force probe (Brodontic®-
ASH/Dentsply), adjusted to 0.25N is
used. The results show that the
agreement both within and
between clinicians could hardly be
rated as ‘fair’ on a site basis.
Approximately one in every three sites
was given a different assessment on
the second examination. Agreement
on a quadrant basis was slightly
better. Furthermore, the direction
of the probing influences the
number of provoked bleeding sites.
Angulation of the probe produces
consistently less bleeding compared
with parallel placement of the
probe.
IMAGEM 4
Comparison of a conventional
and modified tooth stain index
Macpherson LMD*, Stephen KW*,
Schæfer F, Huntington E and
Joiner A
(*University of Glasgow Dental
Hospital and School, Glasgow UK)
J Clin Perio 27,(11), p854, 2000
A modified tooth stain index was
evaluated and the effect of dietary
factors on stain formation
determined. At baseline, 182 adult
volunteers were given a full oral
prophylaxis followed by stain
assessment using a modification of
the Lobene Index. This involved
assigning separate scores to the
mesial (M) and distal (D) sites of
each tooth, in addition to the
standard gingival area (G) and
tooth body (B). For each site, stain
intensity and areas were scored.
The sum of (intensity x area) scores
was calculated for all sites (GBMDvalue)
and for the gingival and
body sites only (GB-value). The
subjects used a standard abrasive
dentifrice and a soft toothbrush for
6 weeks. Stain was reassessed and
the average increase in GBMDvalue
was 20.9 (sd=9.9) (buccal
aspect) and 29.9 (sd=18.0) (lingual
aspect). The corresponding GBvalues
were 4.4 (sd=4.8) and 12.5
(sd=10.2). The coefficients of
variation of the GBMD index values
were consistently lower than those
of the GB values. Smoking and
tea-drinking were found to be the
only significant (p<0.001) factors
investigated for stain formation. It
is concluded that the modified
index may be well advantageous to
its conventional counterpart
because sites with most visible stain
are assessed separately and
because it may also offer higher
discriminatory power due to a lower coefficient of variation.
Laboratory Studies
Comparison of methods for
determining the prosthetic
metal ion of bacterial
superoxide dismutases in crude
extracts
McEuen AR* Hill HAO* Dring GJ
and Ingram GS
(*University of Oxford)
Dev Biochem 1980, 11a, 272-283
Three different types of superoxide
dismutase (SOD) have been
characterised on the basis of the
prosthetic metal ion. The copper
and zinc containing enzyme, with
two exceptions has been found
exclusively in eukaryotes, the
manganese-containing enzyme has
been found in both prokaryotes
and eukaryotes, and the ioncontaining
enzyme has been found
predominantly in prokaryotes,
though it has recently been
reported in eukaryotic algae and
higher plants. The manganese and
iron super-oxide dismutases are
closely related on the basis of
amino and sequence homology,
while the cuprozinc enzymes form
a phylogenetic class of their own.
Presented here are three methods
for the identification of the
prosthetic metal ion and superoxide
dismutases; the merits and
limitations of each method are
discussed.
Studies of a periodontal tissue
lesion in the rat treated or
untreated with chlorhexidine
digluconate
Kenworthy R and Baverel M
J
Clin Periodontol 1981, 8,
349-358
The studies currently reported
formed part of an enquiry whose
overall objective was to identify a
suitable animal model upon which
initial screening of compounds and
formulations with prophylactic
and/or therapeutic potential in
periodontitis could be carried out.
An earlier study (Rovin et al., 1966)
reported that periodontal
inflammation could be produced in
the conventional laboratory rat by
application of a ligature to the
molar teeth. The present paper
describes the pathological and
histo-pathological changes in the
periodontium following application
of ligatures to the molar teeth of
young rats, and the tissue
responses observed after topical
application of chlorhexidine
digluconate. Plaque formed rapidly
and an acute periodontitis was
induced; application of increasing
concentrations of chlorhexidine
digluconate gave a progressive
diminution in the severity of the
lesions. The major bacterial
components of the plaque were
actinomycetes and streptococci.
Zinc and its role as an antimicrobial
agent
Cummins D
Proceedings XXIV ICCC, Chemica
Chronika 1986 (special issue), 902
Effect of speciation of zinc on
metabolism of streptococcus
mutans
Watson GK, Jones S, Prottey C and
Cummins D
J Dent Res 1986, 65, 96
Metal ions and their
interactions with biological
fluids: speciation of trace metals
in saliva
Hurford, SR*, Christie GL*,
Williams DR*, Cordery CS,
Cummins D and Riley Pl
(*Department of Applied
Chemistry, UWIST, Cardiff, UK)
Proceedings XXIV ICCC, Chemica
Chronika 1986 (special issue), 738
The importance of the
speciation of zinc to its activity
as an anti-microbial agent
Cummins D, Jones S and
Watson GK
Proceedings ICBIC 3, Recueil
1987,106, 435
A comparison of calculus
inhibitory systems
Ingram GS and Carter P
J Dent Res 1987, 66, 191
The inhibition of facultative and
obligate anaerobic bacteria by
Triclosan
Ritchie JA and Jones CL
Anaerobes Today 1988, 240
Edited by JM Hardie and SP
Borriello
Importance of speciation of zinc
to its antimicrobial activity
Cummins D and Watson GK
J Dent Res 1988 (special issue), 67,
402
The effect of zinc and citrate
salts on hydroxyapatite
formation
Harrap GJ
J Dent Res 1988, 67, 320
Effects of anticalculus agents on
hydroxyapatite crystal growth
Ingram GS and Carter P
Caries Res 1988, 22,101
Use of a zinc-containing
dentrifice: Uptake of zinc by
hydroxyapatite and by dental
calculus
Ingram GS, Tan-Walker R, Gilbert
RJ and van der Ouderaa FJG
J Dent Res 1988, 67 (special issue),
402
The effect of zinc citrate on oral
bacteria in continuous culture
Jones CL, Purdell-Lewis D and
van der Ouderaa FJG
J Dent Res 1988 (special issue), 67,
327
Adsorption of zinc by plaque
and hydroxyapatite
Ingram GS, Tan-Walker R, Watson
GK and Gilbert RJ
Caries Res 1989, 23, 106
Delivery Systems for Agents in
Supra- and Sub-gingival Plaque
Control
van der Ouderaa F J G and
Cummins D
J Dent Res 1989, 68, 1617-1624
Delivery vehicles for anti-plaque
agents function to provide a
microbiologically, chemically, and
physically stable environment for
the drug prior to use, to optimize
bio-availability at the site of action
in an appropriate physical and
chemical form, to promote uptake
at oral receptor sites, and to
provide a dosage vehicle
compatible with the oral hygiene
methods and the expected degree
of compliance of the patient.
Criteria for delivery in most
reported studies relate primarily to
gross microbiological and clinical
parameters rather than to
concentrations of the drug
delivered. Few reports identify the
nature of the oral reservoirs of any
of the individual anti-plaque agents
studied so far. Comparison of the
effectiveness of delivery of single
agents via different routes is a
prerequisite to the optimization of
effective delivery vehicles for
specific applications, and yet
surprisingly few data of this type
exist. Key factors which affect the
delivery and, hence, efficacy of
anti-plaque agents in vivo include
the pH and state of ionization of
the drug, the solubility and rate of
solubilization of the drug (both in
the vehicle and at the site of
action), physical and chemical
interactions between the drug and
its excipients, and last, but not
least, drug dosage and dosing
protocol.
Many vehicles have been
successfully used for administration
of doses of topical agents of widely
differing chemical natures for
supragingival plaque control.
Examples are alcoholic rinses,
dentifrices, aqueous and nonaqueous
gels, impregnated dental
floss, chewing gum, irrigators, and,
recently, sustained-release devices.
Sub-gingival plaque control has
traditionally been achieved by
systemic administration of drugs
such as tetracycline and
metronidazole. Delivery to the oral
cavity is thus obtained via gingival
sulcus fluid and saliva. Experimental
systems for direct delivery into
periodontal pockets via dialysis
tubing or acrylic strips have also
been described, with some groups
recently reporting biodegradable
controlled-release devices. In
addition, irrigators have been used.
These local delivery systems have
the potential to deliver the antiplaque
effect at much lower total
body load of the drug.
Differences between the
distribution of epidermal
growth factor receptor in
human skin and oral mucosa,
detected by immunohistology
and EGF binding studies
Partridge M*, Smith CG and
Green MR
(*Charing Cross Sunley Research
Centre, Lurgan Avenue,
Hammersmith, London)
Epithelia 1989, 1, 179-190
The localisation of the EGF-receptor
in normal human skin and oral
mucosa from different sites has
been determined using two
different light microscopic methods
and an immuno-ultrastructural
technique. Immunoreactive
receptors were localised using a
monoclonal antibody against the
human receptor. Accessible,
unoccupied receptors were
visualised by 125I-EGF binding
studies. Basal cells were always
found to express EGF-receptors,
while suprabasal cells showed
equivalent, variable or no receptor
expression. As cell proliferative
capacity is predominantly
associated with basal cells, it is
concluded that the expression of
EGF-receptors is a necessary but
insufficient indicator of cell
proliferative potential. Marked
tissue differences in the patterns of
EGF-receptor expression on
epidermis, orthokeratinised,
parakeratinised and nonkeratinised
oral mucosa were consistently
observed. Explanations for these
variations are discussed, and it is
proposed that the pattern of EGFreceptor
expression may be related
to the type of epithelial
keratinisation. Nuclear EGFreceptors,
predominantly associated
with chromatin, were seen using
immunoelectron microscopy in all
tissues examined suggesting a role
for the EGF-receptor in gene
regulation.
Computer model relating
chemistry to biological activity
of metal anti-plaque agents
Cummins D and Watson GK
J Dent Res 1989, 68, 1702-1705
It is clear from literature reviews
that the clinical and microbiological
activity observed for zinc, copper,
tin and silver compounds are
variable and not well understood.
We propose that much of this
variation in biological response can
be rationalized if due account is
taken of the chemistry of the metal
ion.
The use of computer simulation
offers a new approach to
understanding of the delivery,
distribution and bio-availability of
metal ions. Application to studies
on the distribution of stannous in
solution in the presence of fluoride,
and the importance of zinc
speciation for antimicrobial action
of zinc have demonstrated the
value and the power of computer
simulation to aid our
understanding of the action of
metal-based anti-plaque agents.
Anti-bodies for the detection of
proteoglycan fragments from
alveolar bone
Al Bayathy H*, Embery G*,
Waddington RJ* and Harrap G
(*Department of Basic Dental
Science, University of Wales,
Cardiff)
J Dent Res 1990, 69, 980
Antibacterial testing of metal
ions using a chemically defined
medium
Ritchie JA and Jones CL
Letters in Applied Microbiology
1990, 11, 152-154
Data from in-vitro tests on
potential germicides can be greatly
influenced by the culture medium.
The bioavailability and biochemical
reactivity of the biocides can be
influenced by chemical interference
with media components (Spooner
& Sykes, 1972). Bird et al (1985)
showed that metal ions are
particularly prone to chemical
interferences. A chemically defined
solid medium has been developed
to monitor the antibacterial activity
of metal ions. The minimum
inhibitory concentrations of zinc
and silver have been determined
against a range of bacteria using
this medium.
Crevicular Fluid, Interleukin-1B
and 1gG Subclasses in
Periodontitis
Wilton J*, Bampton J*, Hurst T**,
Powell J and Caves J
(*Medical Research Council Dental
Unit, London
**London Hospital Dental School,
London)
J Dent Res 1991, 70, 353
Crevicular Fluid IgG Subclasses
in Health and Periodontitis
Powell J, Alexander A* and
Smales F**
(*Institute of Naval Medicine,
Gosport, Hampshire, UK)
(**London Hospital Medical
College, London, UK)
J Dent Res 1991, 70,353
Comparison Between CLSM and
SE for the Study of Plaque
Jones CL, Cummins D, Cummins PG
and Howard CV*
(*University of Liverpool, UK)
J Dent Res 1991, 70, 368
Anti-plaque Agents. Rationale
and Prospects for Prevention of
Gingivitis and Periodontal
Disease
van der Ouderaa FJG
J Clin Periodontol 1991, 18,
447-454
Oral health surveys have shown
that even in countries with
established patterns of oral hygiene
habits, most individuals have
relatively poor gingival health. This
is due to a low interest in
complying with oral health
procedures. A number of factors
are apparent when investigating
compliance to oral hygiene habits,
viz only approximately 50% of the
population brushes twice a day or
more, brushing time is probably
much too short and use of dental
floss is not very prevalent. Studies
of the effect of motivation on oral
hygiene suggest that improvements
can be achieved, but these are not
maintained unless motivation is
continuously reinforced. This
suggests that topically applied antiplaque
agents should be used to
augment mechanical plaque
control. A number of product
forms are available to delivery antiplaque
agents i.e., mouthrinses,
dentifrices, aqueous gels, and
additionally floss, chewing gum
and lozenges. Any product form
should provide a physically,
chemically and microbiologically
stable environment for the agent
concerned. It should facilitate
optimal bioavailability of the agents
at the site of action and encourage
patient compliance. Anti-plaque
agents for topical administration
should have the following
properties: high intrinsic efficacy
against a broad spectrum of oral
organisms, toxicological and
ecological safety, oral substantivity,
no adverse reactions and good
chemical stability. A number of
classes of anti-plaque agents have
been identified such as positively
charged organic molecules, metal
salts, phenols, enzymes, peroxides,
sugar substitues, fluorides and
surface modifying agents. In order
to achieve optimal bioavailability,
the agent to be dosed should be
compatible with the product form
used. The two major product forms
are rinses and dentifrices. With
respect to rinses as the product
form, the formulation excipients
are generally compatible with
positively charged organic agents,
phenolic agents and some metal
salts. In the case of dentifrice
formulations, interactions of the
agent with the product excipients
limit compatibility to some metal
salts and non-charged phenolic
agents, Triclosan being a well
researched example. The
combination of metal salts, in
particular zinc, and the phenolic
agent Triclosan has been shown to
represent a further powerful route
to enhance systems for daily
plaque control.
Anti-plaque Dentifrices: Current
Status and Prospects
van der Ouderaa FJG and
Cummins D
Int Dent J 1991, 41, 117-123
A dentifrice can, in principle, be an
effective delivery vehicle for antiplaque
agents, provided
bioavailability of the agent
concerned can be achieved,
because the agent is applied and
delivered at the site of action and
favourable patient compliance can
be obtained. It is widely assumed
that anti-plaque agents need to be
retained in the oral cavity after
application (‘substantivity’). To use
a dentifrice as a dosing vehicle
successfully the anti-plaque agents
have to be compatible with the dentifrice formulation to achieve
release from the formulation and
subsequent retention of the antiplaque
agent after application.
Recently, progress has been
achieved with a selection of
compatible anti plaque agents for
inclusion in a dentifrice such as
metal ions and non-charged
phenolic agents. Studies on longterm
unsupervised brushing have
shown favourable anti-plaque and
anti-gingivitis activity from antiplaque
agents dosed from a
dentifrice.
Routes to Chemical Plaque
Control
Cummins D
Biofouling 1991, 4, 199-207
A logical approach to the
prevention of periodontal disease is
through excellent supragingival
plaque control. Such control is not
generally achieved by mechanical
oral hygiene procedures alone.
Thus, there is a clear rationale for
the use of anti-plaque agents to
augment mechanical means. The
principal routes to chemical plaque
control are to prevent colonization
of the tooth surface, to inhibit the
growth of microorganisms, to
prevent plaque maturation, to
modify plaque biochemistry and to
modify plaque ecology to a less
pathogenic flora. The most
successful approach to date has
been to use broad spectrum
antimicrobial agents to reduce
plaque growth and, in
consequence, plaque metabolism.
Currently, only the chlorhexidine
and Listerine mouthwashes and a
toothpaste containing zinc citrate
and Triclosan have proved efficacy
in controlled clinical trials. Their
effectiveness is a result of good
oral substantivity as well as broad
spectrum antimicrobial activity.
All other routes to chemical plaque
control are in the early stages of
development. Several approaches
have shown sufficient
potential to warrant further
research. As understanding of the
role of specific plaque
microorganisms in the aetiology of
disease increases, more rational,
sophisticated approaches to
chemical plaque control become
feasible. In particular, routes to
control specific pathogenic
organisms may become a reality.
Anti-plaque agents for Supragingival
Plaque Control –
Rationale and Outlook
van der Ouderaa FJG
Recent advances in
Periodontology II
Eds: Gold S I, Midda M and
Mutlu S
Excerpta Medica Amsterdam 1991,
129-136
Agents for daily use to control
plaque and gingivitis have been
successfully formulated in product
systems such as dentifrice and
mouthrinses. A number of rinse
and gel systems containing
positively charged agents are
available. These agents are
however incompatible with
dentifrices. In contrast metal salts
and non-charged agents, such as
Triclosan, are bio-available from this
vehicle. Good results have also
been obtained using a combination
of two agents i.e., Triclosan and
zinc citrate.
Thermodynamic Formation
constants and Solid State
Properties for the Interaction of
Zn(II) Ions with Citrate,
Phenolsulphate,
Monofluorophosphate and
Saccharinate
Christie GL**, Cummins D, Duffield
JR, Hurford SR***, Morris CR*,
Riley PI, Vesay JA* and
Williams DR*
(*School of Chemistry, University of
Wales, Cardiff, UK)
(**Kingston Polytechnic, Surrey,
UK) (***Department of Chemistry,
Manchester Polytechnic,
Manchester, UK)
J Inorg Biochem 1991, 42,
273-287
The role of zinc as a therapeutic
ingredient of dentifrices is reviewed
and chemical speciation modelling
is suggested as a means of
optimizing the beneficial effects.
The solid state chemistry of zinc
citrate, monofluorophosphate, and
saccharinate is reported as FTIR
spectra. Concentration formation
constants were measured by
solution potentiometry.
Inhibition of Acid Production by
Streptococcus Mutans NCTC
10449 by Zinc and the Effect of
Metal Speciation
Watson GK, Cummins D and
van der Ouderaa F J G
Caries Res 1991, 25, 431-437
Ionic zinc as zinc sulphate was
strongly inhibitory to acid
production from glucose by
washed cell suspensions of
Streptococcus mutans NCTC 10449
in a pH-stat assay (50% inhibition
at 0.1mM zinc). Zinc was adsorbed
to the cells (up to 8µg/mg cells).
Several other zinc salts that
dissociated to free zinc ions were
also strongly inhibitory. Zinc in a
partially complexed form as zinc
citrate was less strongly inhibitory
(50% inhibition at 0.2mM zinc),
and adsorption of zinc was lower
(up to 3µg/mg cells). Stoichiometric
addition of ethylenediaminetetraacetic
acid (EDTA) to assays
containing zinc sulphate completely
removed inhibition and adsorption
of zinc. A good correlation
between inhibition of acid
production and adsorption of zinc
was found, and zinc adsorption
was correlated with the levels of
free zinc ion in the assay mixtures.
The strongly anionic complexes of
zinc, Zn(CIT)-, Zn(CIT)42_ and
Zn(EDTA)2–, were not inhibitory
and did not adsorb to the bacterial
cells.
Anti-calculus effect of a
dentifrice containing 0.5% zinc
citrate trihydrate
Segreto VA*, Collins EM*,
D’Agostino R**, Cancro LP**,
Pfeifer HJ*** and Gilbert RJ
(*University of Texas Health Science
Centre, San Antonio, TX)
(**Department of Mathematics,
University of Boston, Boston, MA)
(***4230 Secor Road, Toledo, OH,
USA).
Community Dent Oral Epidemiol,
1991, 19, 29-31
A double blind three-month
anticalculus clinical study was
conducted to determine the
magnitude of the anti-tartar effect
to be derived from use of a 0.5%
zinc citrate dentifrice. From a
population of 1600 subjects
exhibiting calculus, 1210 subjects
(aged 18 and over) were selected
and received a dental prophylaxis.
The subjects were initially stratified
on the basis of calculus score, age,
and sex, then allocated randomly
to a 3-month usage period of one
of two treatment groups. These
were a dentifrice containing 0.5%
zinc citrate or a control dentifrice
without zinc citrate. Calculus was
assessed using the Volpe-Manhold
Index. Oral soft tissue status was
assessed throughout the course of
the study. At the conclusion of the
study 964 subjects had completed
the trial: 486 using the zinc citrate
dentifrice and 478 using the
control. The results showed that
the mean calculus scores in the
group using the dentifrice
containing zinc citrate were 13.7%
lower than those of the group
using the control dentifrice. This
finding was statistically significant
(p<0.05). No adverse effects related
to the use of either dentifrice were
observed.
Anti-microbial activity of
stannous and stannic
Watson GK, Waterfield PC and
Cummins D
J Dent Res 1992, 71, 708
Identification of salivary zinc
binding proteins
Davey H*, Embery G*, Cummins D
and Weir AJ
(*Department of Basic Dental
Science, University of Wales Coll
Med Dent School, Cardiff, UK)
J Dent Res 1992, 71, 323
Effect of pre-treatment with
saliva or glucosyltransferases on
biofilm development
Bradshaw DJ*, Marsh PD*, Watson
GK and Cummins D
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
J Dent Res 1992, 71, 731
Pedocin PA-1 from pediococcus
acidilactici PAC1.0: mode of
action and genetics
Chikindas ML, Garcia MJ*, Driessen
AJM*, Marugg JD, Ledeboer AM,
Abee T*, Konings WN*, Venema
G, Kok J*
(*Departments of Genetics and
Microbiology, University of
Groningen, The Netherlands)
FEMS Microbiology Reviews, 1993,
12, 123
Bacterial adhesion to apatite
materials: Electrokinetic aspects
Yelloji Rao MK*, Somasundaran
P*, Schilling KM, Carson R and
Ananthapadmanabhan KP
(*Henry Krumb School of Mines,
Columbia University, NY, USA)
Colloid Surfaces A: Physico Chem
1993, 79, 293-300
The role of the electrokinetic
properties of Streptococcus sanguis
and Actinomyces naeslundii in
determining their adhesion to
apatite minerals is examined. It is
shown that bacterial adhesion onto
a mineral surface takes place even
when both the surfaces are
negatively charged, and that the
adhered layer is resistant to
washing. Also, the mineral fines
after exposure to bacteria exhibit
zeta potential values which are in
between those of the mineral and
the bacteria, but lie closer to that
of the mineral. In the absence of salivary proteins, the inorganic
species present in saliva alter the
magnitude of the surface charge
but do not affect the bacterial
adhesion process. Dissolved apatite
mineral species (in supernatant
solutions) are also shown to
decrease the magnitude of the zeta
potential of the bacteria. The
observed adsorption of negatively
charged bacteria onto negatively
charged minerals suggests that
electrostatic interactions are not
the primary factors determining
adhesion.
The effects of Triclosan and zinc
citrate, alone and in
combination, on a community
of oral bacteria grown in vitro
Bradshaw DJ*, Marsh PD*, Watson
GK and Cummins D
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
J Dent Res 1993, 72, 25-30
A mixed-culture chemostat system
has been used as a more stringent
laboratory system for evaluation of
the antimicrobial effects of
Triclosan and zinc citrate. The
inhibitors were added alone, and in
combination, as a pulse (a high
initial inhibitor concentration which
decreased with time) or as a dose
(concentration of inhibitor
increased with time) to give
maximum concentrations of
34.5µmol/L Triclosan and
39.8µmol/L zinc citrate. When
dosed, Triclosan inhibited A.
viscosus and all five Gram-negative
species, whereas zinc citrate had
less effect, probably due to
complexation by media
components. Similar effects were
seen when Triclosan was pulsed,
except that S. mutans was the
most sensitive Gram-positive
species and V. dispar was
unaffected. However, when the
inhibitors were dosed or pulsed in
combination, marked
complementary and additive
inhibitory effects were observed,
particularly against Gram- and
negative species, although S.
gordonii S. oralis were relatively
unaffected. The data confirm that
increased effects can be obtained
with suitable combinations of
antimicrobial agents and suggest
that, under certain conditions, apparently broad-spectrum
antimicrobial agents may be acting
more selectively than hitherto
suspected.
Effect of oxygen and innoculum
composition on development of
mixed culture biofilms
Bradshaw DJ*, Marsh PD*, Watson
GK and Schilling K
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
J Dent Res 1994, 73, 849
Effect of pre treatment with
parotid saliva in the
development of mixed culture
systems
Bradshaw D*, Marsh PD*, Watson
GK and Schilling K
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
Caries Res 1994, 28, 182.
The targetting of phospholid
liposomes to bacteria
Jones M*, Kaszuba M*, Reboiras
MD**, Lyle IG, Hill KJ*, Song YH*,
Wilmot SW* and Creeth JE
(*School of Biological Sciences,
University of Manchester
**Depatmento de Quimica,
Faculdad de Ciencias, Universidad
Autonoma de Madrid)
Biochimica et Biophysica 1994,
1196 (1), 57-64
Phospholipid liposomes have been
prepared from phospholipid
mixtures including
dipalmitoylphosphatidylcholine/pho
sphatidylinositol (DPPC/PI) and
DPPC/ dipalmitoylphosphatidylglycerol
(DPPC/DPPG) mixtures and
targeted to adsorbed biofilms of
the skin-associated bacteria
Staphylococcus epidermidis and
Proteus vulgaris and the oral
bacterium Streptococcus sanguis.
The effects of time, liposome
concentration and density of
bacteria in the biofilm have been
studied in detail for Staphylococcus
epidermidis. The targeting (as
assessed by the apparent
monolayer coverage of the biofilms
by liposomes) to the biofilms was
found to be sensitive to the mol%
of PI and DPPG in the liposomes
and optimum levels of PI were
found for targeting to each
bacterium. The use of PI and DPPGcontaining
liposomes for the
delivery of the bactericide,
Triclosan, to biofilms of
Staphylococcus epidermidis was
studied as a function of the
amount of Triclosan carried by the
liposomes. All the liposome systems
tested inhibited the growth of
bacteria from the biofilms after
brief (two min) exposure to
Triclosan-carrying liposomes. At low
Triclosan levels bacterial growth
inhibition by Triclosan-carrying
liposomes exceeded that by an
equivalent level of free Triclosan.
After short periods (min) of
exposure of biofilms to Triclosancarrying
liposomes the bactericide
was shown to preferentially
concentrate in the biofilms relative
to its liposomal lipid carrier. The
results suggest that phospholipid
liposomes with appropriately
chosen lipid composition have
potential for the targeting and
delivery of bactericide to bacteria.
Immunological characteristics of
a synthetic peptide associated
with a catalytic domain of
mutans streptococcal
glucosynltransferase
Smith DJ*, Taubman MA*, King
WF*, Eida S, Powell JR and
Eastcott J
(*Department of Immunology,
Forsythe Dental Centre,
Boston, USA)
Infection and Immunity 1994, 62,
5470-5476
The immunogenicity of a multiple
antigenic peptide construct
consisting of four copies of the
synthetic 21-mer peptide
DANFDSIRVDAVDNVDADLLQ was
measured. The composition of this
peptide was derived from a
sequence in the N-terminal region
of mutans streptococcal
glucosyltransferases (GTFs)
containing an aspartic acid
implicated in catalysis. The peptide
(CAT) construct was synthesized as
a tetramer on a lysine backbone
and subcutaneously injected into
Sprague-Dawley rats for polyclonal
antibody formation or
intraperitoneally injected into
BALB/c mice, and then spleen cell
fused with Sp2/0Ag14 murine
myeloma cells for monoclonal
antibody formation. The resulting
rat antisera and mouse monoclonal
antibodies reacted with CAT and
with native GTF isozymes from
Streptococcus sobrinus and
Streptococcus mutans (in enzymelinked
immunosorbent assay and
Western blot [immunoblot]
analyses). Functional inhibition of
the water-insoluble glucan
synthetic activity of S. sobrinus
GTF-1 was demonstrated with an
immunoglobulin M anti-CAT
monoclonal antibody (>80%
inhibited) and with rat sera
(approximately 17% inhibited). The
monoclonal antibody preparation
also modestly inhibited the watersoluble
glucan synthetic activity of
an S. mutans GTF mixture. These
results suggest that the CAT
peptide contains B-cell epitopes
that are similar to those of intact
mutans streptococcal GTFs and has
the potential to elicit antibody that
can inhibit GTF function. Thus,
sequences within this peptide
construct may have value for
inclusion in a synthetic dental caries
vaccine.
Effect of oxygen and flow-rate
on bacterial survival and biofilm
development
Bradshaw DJ*, Marsh PD*, Watson
GK, Allison C
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
J Dent Res 1995, 74, 853
An in vitro biofilm system for
study of plaque ecology and
physiology
Watson GK, Halliday D, Albiston L,
Singleton S, Allison C
J Dent Res 1995,74, 853
Identification of dissimilatory
sulfate reduction in the human
oral cavity
Holt J, Allison C, Willis CL*,
Gibson GR*
(*Institute of Food Research,
University of Reading,
Reading, UK)
J Dent Res 1995, 74, 846
Optical Imaging and
characterisation of oral biofilms
structures using vital stains and
specific antibody probes
Singleton S, Albiston L, Treloar R,
Mahers E, Hodgson R, Watson G K,
Schilling K and Allison C
The Life and Death of Biofilm Eds:
Wimpenny J, Handley P, Gilbert P
and Lappin- Scott H Bioline, Cardiff
1995, 33-36
Oral biofilms exhibit a diversity of
physiological and biochemical
characteristics super-imposed on a
complex structure. A prerequisite
for studies of the role of biofilm
microstructure in biofilm-specific
activities is a facility for
non-destructive analysis. In this
work confocal laser scanning
microscopy (CLSM) has been used
in conjunction with vital stains and
species-specific monoclonal
antibody (Mab) probes to
investigate oral biofilm structures
formed in vitro. Methods have
been developed for the application
of optical microscopy
in combination with fluorescent
probes and image analysis
programs to investigate early
colonisation of model surfaces by
oral bacteria. In particular,
sampling of relatively large areas
may provide information on
changing patterns of colonisation
by specific organisms against the
total biofilm biomass and a
parameterised description of the
process as a function of time and
spatial distribution. Studies
undertaken using 3D image sets
generated by CLSM of smaller
representative samples have
demonstrated (i) confocal imaging
and enumeration of putatively
viable organisms in 3D structures,
(ii) confocal imaging and
enumeration of Mab-labelled
bacteria in biofilms and (iii)
parameterisation of 3D structural
distribution characteristics of
representative biofilm segments.
These methods form the basis of
fundamental investigations into
biofilm structure and the
development of an ability to characterise biofilm structures using
statistically relevant data.
IMAGEM 5
The effect of conditioning films
on adhesion
Bradshaw DJ*, Marsh PD*, Watson
GK and Schilling K
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
The Life and Death of Biofilm
Eds: Wimpenny J, Handley P,
Gilbert P and Lappin-Scott H
Bioline, Cardiff 1995, 47-52
A well-characterised chemostat
system, containing 10 oral bacteria,
has been modified to allow the
study of biofilms growing on the
surface of hydroxyapatite (HA)
discs. This paper describes
experiments examining the effect
of pre-treatment of HA discs with
bacterial supernatants containing
glucosyltransferase (GTF activity,
human parotid or whole saliva, on
the development of these oral
biofilms. Treatment with crude GTF
preparations from Streptococcus
mutans or from S. sanguis
produced increases in the total CFU
recoverable from discs, in
particular numbers of P. gingivalis
and S. mutans. In addition, S.
sanguis GTF enhanced numbers of
F. nucleatum, V. dispar and S.
sanguis cells in biofilms,
while treatment with S. mutans
GTF produced little effect on these
species. Parotid saliva reduced
streptococci, but enhanced
numbers of F. nucleatum in 1 hour
biofilms; no effects on total
numbers or on individual species
were apparent after 4 days. Whole
saliva had little effect on total
numbers in biofilms, but did have
selective effects. Numbers of
streptococci were increased, and
Gram
Growth, incidence and activities
of dissimilatory sulfate-reducing
bacteria in the human oral
cavity
Willis CL*, Gibson GR*, Allison C,
Macfarlane S* and Holt JS
(*Dunn Clinical Nutrition Centre,
University of Cambridge, UK)
FEMS Microbiology Letters 1995,
129, 267-272
Viable counts and activities of
sulfate-reducing bacteria were
determined in the oral cavities of 12
healthy volunteers. Of these, 10
harboured viable sulfate-reducing
bacteria populations. Six separate
sites were sampled: the posterior
tongue, anterior tongue, mid buccal
mucosa, vestibular mucosa,
supragingival plaque and subgingival
plaque. Sulfate reducing bacteria
occurred in all areas, with the highest
incidence in supragingival plaque.
Viable counts and sulfate-reducing
activities in each of the regions varied
from 0 to 108cfu (g wet weight)-1
and from 0 to 50nmol (g wet
weight)-1 h-1, respectively. As
sulfate-reducing bacteria can be
detected in the oral cavity, they may
potentially be involved in terminal
oxidative processes carried out by the
microflora of the mouth.
Requirement for FlhA in flagella
assembly and swarm-cell
differentiation by Proteus
Mirabilis
Gygi D*, Bailey MJ*, Allison CA
and Hughes C*
(*Department of Pathology,
University of Cambridge,
Cambridge, UK)
Molecular Microbiol 1995, 15,
761-9
Swarming by Proteus mirabilis is
characterized by cycles of rapid
population migration across
surfaces, following differentiation
of typical rods into long, aseptate
swarm-cells that over express
flagella and virulence factors,
particularly haemolysin. A
non-swarming Tn5phoA mutant
was unable to synthesize flagella,
to fully elongate or to induce high
levels of the toxin. The mutation
lay within a 2091bp gene encoding
a homologue of the Escherichia coli
FlhA belonging to a family of
proteins that are required for
assembly of flagella or virulence
proteins and that are suggested to
act either directly in membrane
translocation and/or in regulating
synthesis of the export apparatus.
In trans expression of multicopy
FlhA restored cell elongation and
migration and generated
differentiation-specific
hyperexpression of flagellin and
toxin genes to levels above those
seen in the wild-type strain.
Transcription of FlhA was strongly
induced during differentiation,
from its own putative sigma 28
promoter. The results suggest a
mechanistic coupling of flagella
assembly and swarm-cell
differentiation.
Coaggregation between
Prevotella nigrescens and
Prevotella intermedia with
Actinomyces naeslundii strains
Cookson AL*, Handley PS*, Jacob
AE*, Watson GK and Allison C
(*Dept. Microbiology, University of
Manchester, Manchester, UK)
FEMS Microbiology Letters 1995
132, 291-296
Using a visual coaggregation assay,
43% (6 of 14) of Prevotella
nigrescens and 50% (4 of 8) of
Prevotella intermedia strains
coaggregated with Actinomyces
naeslundii strains which
represented the six Actinomyces
coaggregation groups (A to F). For
both species, coaggregation
occurred most frequently with A.
naeslundii strains from
coaggregation groups C, D and E.
No coaggregation was observed
with Actinomyces israelii,
Actinomyces odontolyticus or the
six oral Streptococcus species.
Coaggregation was not
inhibited by lactose, saliva or
serum. Pretreatment of Prevotella
strains with heat, SDS and
proteinase K abolished
coaggregation when the treated
cells were added to untreated
Actinomyces strains. The same
pretreatment of the Actinomyces
strains had no effect on their ability
to coaggregate with untreated
Prevotella strains. Pretreatment of
all coaggregating P. nigrescens
strains with trypsin abolished
coaggregation, whereas the
coaggregation ability of the P.
intermedia and Actinomyces strains
was resistant to trypsin
pretreatment. Pretreatment of the
strains of both Prevotella species
and the Actinomyces with
periodate abolished coaggregation
in all cases. These results suggest
that the Prevotella strains each
possess a protein coaggregation
adhesin, which for the P.
intermedia strains is resistant to
trypsin, that interacts with a
non-protein receptor on the A.
naeslundii strains.
A modified chemostat system to
study the ecology of oral
biofilms
Bradshaw DJ*, Marsh PD*,
Schilling KM and Cummins D
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
J Appl Bact 1996 80, 124-130
Previously, we developed a
chemostat system to study the
behaviour and properties of a
community of up to 10 species of
oral bacteria. The present study
describes modification of this
system to incorporate removable
and replaceable hydroxyapatite (the
major mineral in human dental
enamel) disks on which biofilms
could develop. Hydroxyapatite disks
were immersed in the chemostat
for known time periods, and the
bacterial content of biofilms
determined by viable counting.
Initial deposition rates were rapid,
with all 10 species detected after
1h, and the numbers of bacteria in
biofilms continued to increase for
21d. The species composition of
biofilms reflected that of the
surrounding fluid phase, and
showed only limited signs of the
type of ‘species succession’ which
is observed in developing dental
plaque in vivo, although anaerobic
species increased in proportion in
older biofilms. Four-day biofilms
showed the least variability and
were chosen as the ‘standard
biofilm’ for more detailed study.
Variability in the bacterial
composition of 4-d biofilms was
comparable both within a single
chemostat run and between
independent chemostat runs.
Glucose pulsing in the absence of
pH control resulted in the selection
of cariogenic species; the
disruption of the biofilm
community was less marked than
that of the equivalent planktonic
culture. The model system has
considerable potential in studying
the effects of a variety of factors
on biofilm development, as well as
in comparing the efficacy of
antimicrobial systems against
biofilms.
Effect of oxygen, inoculum
composition and flow rate on
development of mixed
culture oral biofilms
Bradshaw DJ*, Marsh PD*,
Allison C, Schilling K M
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
Microbiology 1996,142, 623-9
The effect of aeration on the
development of a defined biofilm
consortium of oral bacteria was
investigated in a two-stage
chemostat system. An inoculum
comprising 10 species, including
both facultatively anaerobic and
obligately anaerobic bacteria, and
species associated with oral health
and disease, was inoculated into an
anaerobic first-stage chemostat
vessel. The effluent from this
chemostat was linked to an
aerated [200ml C02/air (5:95v/v)
min-1] second-stage vessel, in
which removable hydroxyapatite
discs were inserted to allow biofilm
formation. Comparisons were
made of planktonic and biofilm
communities in the aerated
second-stage vessel by means of
viable counts. Both planktonic and
early biofilm communities were
dominated by Neisseria subflava,
comprising >40% of total c.f.u. in
the fluid phase, and >80% of c.f.u.
in 2h biofilms. Obligate anaerobes
persisted in this mixed culture, and
succession in biofilms led them to
predominate only after 7d. Despite
the continuous addition of air, the
dissolved oxygen tension (dO2)
within the culture remained low
(<5% of air saturation), and the
redox potential (Eh) was -275mv. In
order to assess the significance of
the presence of N. subflava in
community development, a
subsequent experiment omitted
this aerobe from the inoculum, to
produce a nine-species culture. The
planktonic phase was
predominated by three
streptococcal species, Prevotella
nigrescens and Fusobacterium
nucleatum. Biofilms again
underwent successional changes,
with anaerobes increasing in
proportion with time. In contrast to
the culture including
N. subflava, dO2 was 50-60% of
air saturation, and the Eh was
+50mV. In the final experiment, the
rate of addition of first-stage
culture was reduced to 1/10 of that
in the previous experiment, in order
to determine whether anaerobes
were growing, rather than merely
persisting in the aerated culture.
IMAGEM 6
The data for the planktonic phase
indicated that the anaerobes were
growing in aerated (dO2 40-50t, Eh
+100mV) conditions. Once again,
anaerobes increased in proportion
in older biofilms. The study
indicates that mixed cultures can
protect obligate anaerobes from
the toxic effects of oxygen, both in
the biofilm and planktonic modes
of growth.
Potential role for coaggregation
in microbial
community-development
in vitro
Bradshaw DJ*, Marsh P D*,
Watson G K, Allison C
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
J Dent Res 1996, 75,1507
Potential role for coaggregation
in microbial community
development in vitro
Bradshaw DJ*, Marsh PD*, Watson
GK, Allison C
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
J Dent Res 1996, 75, 206
Role of
fusobacterium-nucleatum in
anaerobe survival in microbial
communities
Marsh PD*, Bradshaw DJ*,
Watson GK, Allison C
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
J Dent Res 1997, 76,1700
Evidence for multi-species
interactions in oral biofilm
development
Bradshaw DJ*, Marsh PD*, Watson
GK, Allison C
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
J Dent Res 1997, 76,1058
Interactions between facultative
and obligate anaerobes in oral
biofilm development
Bradshaw DJ*, Marsh PD*, Watson
GK, Allison C
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
Advances in Dent Res 1997,
11,187
Modulation of physiological
responses and population
structure of mixed culture
oral biofilms grown in vitro
Allison C, Watson G K,
Singleton S, Schilling K,
Cummins D
Advances in Dent Res 1997,
11,191
positive and Gram-negative rods
were reduced in early biofilms.
Little effect on either total or
specific counts was detected after
4 days.
The results show the value of the
model system in examining
molecules which are important in
initial biofilm attachment and its
subsequent development. As
expected, younger biofilms were
highly dependent on attachment
events, whereas older biofilms were
influenced more by biofilm growth.
Further experiments will
utilise better defined molecules and
treatments, and examine other
factors which may be important in
determining the development of
dental plaque.
Structural analysis of oral
biofilms using optical
microscopy methods
Labarbe R, Treloar R, Watson GK
and Allison C Biofilms: Community Interactions
and Control. Eds: Wimpenny J,
Handley P, Gilbert P, Lappin-Scott H
and Jones M
Bioline, Cardiff 1997, 11-14
This study was undertaken to
develop optical microscopy
methods for the characterisation of
biofilm structures grown under
different physiological conditions.
Confocal microscopy was used to
non invasively image a series of
fluorescently labelled mixed species
oral biofilms grown under a range
of nutrient availabilities. After
restoring the images using a
nearest neighbour deconvolution
algorithm to remove some
microscopy artifacts, image
processing techniques were used to
extract binary microstuctures from
the 3D datasets. A set of
measurements was produced for
each object in these
microstructures and a database of
all measurements generated. This
database was interrogated using
exploratory visual data mining
techniques in an attempt to track
structural changes between the
different samples. Clear differences
in biofilm structural parameters
were noted under different
physiological conditions.
Inter-species interactions in
microbial communities Bradshaw DJ*, Marsh PD*, Watson
GK and Allison C
(*Centre for Applied Microbiology
and Research, Salisbury, UK)
Biofilms: Community Interactions
and Control. Eds: Wimpenny J,
Handley P, Gilbert P, Lappin-Scott H
and Jones M
Bioline, Cardiff 1997, 63-71
Mixed cultures were grown in
chemostats on a habitat-simulating
growth medium including hog
gastric mucin (HGM), in order to
study the community behaviour of
oral consortia. The chemostat
design was varied to allow
development of biofilms in an
aerated second-stage vessel.
Obligate anaerobes were able to
survive and grow in relatively
oxidised environments, but only in
the presence of facultatively
anaerobic species, in both the
biofilm and planktonic phase.
Further experiments suggested that
Fusobacterium nucleatum could
allow coaggregation of obligate
anaerobes with facultative species,
thereby facilitating close metabolic
interactions. Anaerobe survival was
later shown to be greatly reduced
in aerated conditions in the
absence of F. nucleatum. Studies
on an increasingly complex series
of mixed cultures correlated the
greater enzymatic capabilities of
the communities in degrading
HGM with increasing bacterial
numbers. Added species which
increased the HGM metabolism of
the community allowed increases in
numbers of extant species, which
were already present. Many
community interactions which are
often ascribed to the biofilm mode
of growth may also occur readily in
the planktonic phase as a result of
community interactions.
Colonisation and interactions of
Pseudomonas species in binary
culture
Brading MG, Boyle J* and
Lappin-Scott HM*
(*School of Biological Sciences,
University of Exeter, Exeter, UK)
Biofilms: Community Interactions
and Control. Eds: Wimpenny J,
Handley P, Gilbert P, Lappin-Scott H
and Jones M
Bioline, Cardiff 1997, 73-79
Two environmental isolates,
Pseudomonas fluorescens and
P. putida have been used to study
colonisation and interactions at the
surface of two closely related
organisms. A recirulating batch
culture system was attached to a
Modified Robbins Device. Silastic
rubber was used as the
colonisation surface and surfaces
were removed at regular time
intervals for viable count
assessment. In simultaneous
colonisation of the two organisms,
P. fluorescens maintained an
advantage over
P. putida for intial attachment. In
challenge of a monoculture biofilm
with a second organism,
P. fluorescens became incorporated
into a P. putida biofilm faster than
P. putida was detected in P.
fluorescens biofilms. However, one
species did not preclude the other
from being incorporated into the
biofilms. The possible advantages
P. fluorescens has for initial
colonisation will be discussed,
together with other environmental
factors which may affect the
interactions of the two organisms
at the surface.
Early Colonisation during development of oral biofilms
Watson GK, Singleton S, Treolar R and Allison C
Biofilms: Community Interactions
and Control. Eds: Wimpenny J,
Handley J, Gilbert P, Lappin-Scott H
and Jones M Bioline, Cardiff 1997,
81-86
Early events during colonisation of
the hydroxyapatite surface by an
oral consortium have been studied in vitro using image analysis and
quantitative characterisation of the
position, size and shape of
individual cells and groups of cells.
Fluorescent staining allowed
detection of both general biomass
and individual members of the
consortium using specific
antibodies. The results suggest that
initial colonisation by single or
small groups of cells is followed by
a non-linear increase of biomass
and formation of non-random
aggregates of cells. Distribution of Veillonella parvula was never
random during the colonisation
process and the results suggest a
role for coaggregation in the early
colonisation process.
Oral anaerobes cannot survive oxygen stress without interacting with facultative/aerobic species as a microbial community
Bradshaw DJ*, Marsh PD*, Watson GK and Allison C (*Centre for Applied Microbiology and Research, Salisbury, UK)
Letters in Applied Microbiology
1997, 25, 385-387
Anaerobic bacteria are found
commonly as components of mixed
culture biofilms in many aerated
habitats, including the mouth.
Previous studies showed that
anaerobes could survive in
planktonic and biofilm communities
in aerated conditions when part of
a community including facultative
and/or aerobic species, and the
numbers and proportions of
anaerobic species increased as
biofilms aged. When the obligate
anaerobes were grown in the
absence of aerobic/facultative
species, however, they were unable
to grow in either the planktonic or
biofilm culture. The mean survival
times of organisms in the aerated
culture containing four anaerobic
species varied from around 5min
for Fusobacterium nucleatum and Veillonella dispar, to less than 4min
for Porphyromonas gingivalis and Prevotella nigrescens. In addition,
in this culture, the biofilm mode of
growth did not provide a haven for
these bacteria in the absence of
oxygen-consuming species.
Effect of conditioning films on oral microbial biofilm development Bradshaw DJ*, Marsh PD*, Watson GK, Allison C (*Centre for Applied Microbiology and Research, Salisbury, UK) Biofouling 1997,11, 217-226
The aim of the study was to
evaluate the influence of either
host or microbially-derived
conditioning films on biofilm
formation. Hydroxyapatite (HA)
discs were pre-treated either with
parotid saliva (2h incubation), or
with crude glucosyltransferase
(GTF) preparations (3h incubation
in culture supernatant of Streptococcus sanguis or Streptococcus mutans, with
sucrose), and then immersed in a
mixed culture of oral bacteria
grown in continuous culture. Discs
were removed from the culture
after 4d, and biofilms were
detached with a sterile probe.
Numbers of bacteria in the biofilms
on pre-treated discs were
determined by differential viable
counts, and results were compared
with untreated discs. Pre-treatment
with GTF from S. sanguis or S. mutans increased
the total CFU on discs immersed in
the culture for 4d by 29% and
95% respectively, although these
differences were not statistically
significant. The two GTF
preparations had differential
effects, with the S. sanguis preparation increasing
the numbers of S. sanguis,
Streptococcus oralis and
S. mutans, whereas the S. mutans
preparation increased numbers of
S. sanguis, Veillonella dispar,
Fusobacterium nucleatum,
S. mutans and Porphyromonas
gingivalis. It was also notable that
each GTF preparation markedly
enhanced colonisation of the
species from which it was derived.
Parotid saliva treatment produced
no differences in biofilm counts
after 4d. In a further experiment,
parotid saliva-treated discs
immersed in the culture for only Ih
showed a highly significant
increase (p<0.002) of 2.6-fold in
CFU compared with untreated
controls, with the greatest effect
seen on counts of F. nucleatum.
Bacterial products can form a
conditioning film, and may have as
important a role in the degree and
pattern of oral biofilm development
as do host molecules.
IMAGEM 7
Methods for microscopic characterization of oral biofilms: Analysis of colonization, microstructure, and molecular transport phenomena
Singleton S, Treloar R, Warren P, Watson GK, Hodgson R, Allison C
Adv Dent Res. 1997, 11,133-149
Assessment of the role of biofilm
microstructure in biofilm-specific
activities requires non-destructive
measurement techniques for
parameterization of structural
characteristics in parallel with
relevant biochemical and
physiological data. This paper
briefly reviews some current
methods for biofilm structural
analysis, with emphasis on new
developments in optical imaging
and mathematical modeling
methods. Fluorescence imaging
studies of bacterial colonization
events occurring on exposed model
tooth surfaces indicated that
bacterial adhesion to sessile
organisms was of central
importance to the early
colonization process and that this
occurred in a non-random manner.
Structural studies of mature
biofilms by confocal microscopy
demonstrated the spatial
distribution of individual species
using fluorescent antibodies.
Biofilms grown under different
physiological conditions exhibited
differences in structure, and
methods were developed for
parameterizing the spatial
orientations of the bacteria.
Diffusive processes within biofilm
microstructures were studied using
a random walk model in both 2-D
and 3-D. Modeling of convective
flow within biofilm microstructures
was achieved by application of
lattice Boltzmann methodology.
The scratch hardness of in vitro formed pellicle
Joiner A, Linden JA* and Hutchings IM
(*University of Cambridge, UK)
The effects of histatin-derived basic antimicrobial peptides on oral biofilms
Helmerhorst EJ, Hodgson R, van’t Hof W*, Veerman ECI*, Allison C and Amerongen AVN*
(*Academic Centre for Dentistry
(ACTA) Vrije University, Department
of Oral Biochemistry, van der
Boechorststraat 7, 1081,
Amsterdam)
J Dent Res 78: (6) 1245-1250, Jun
1999
Susceptibility of bacteria to
antimicrobial agents is strongly
reduced by the formation of
complex biofilms. We investigated
whether synthetic histatin analogs
with broad-spectrum antibacterial
activity in vitro were also active
against these complex mixtures of
bacteria, as present in saliva and
plaque. In a simplified model
system for dental plaque,
hydroxyapatite discs were placed in
a continuous culture system
comprised of Streptococcus
mutans, S. sanguis, S. salivarius,
Actinomyces naeslundii, Veillonella
parvula, Fusobacterium nucleatum,
and Prevotella intermedia. Ex situ
treatment of the biofilms formed
on these discs with 100 mu g/mL
of peptide dhvar4 significantly
reduced facultative anaerobic, total
anaerobic, and obligate anaerobic
Gram-negative counts with 0.8,
0.5, and 0.5 log units, respectively.
El vivo treatment of salivary
bacteria gave reductions of 0.4,
0.7, and 1.5 log units, respectively.
For ex vivo treatment of plaque
bacteria, reductions of 0.4, 0.4,
and 1.4 log units, respectively, were
found. In both saliva and plaque
samples, obligate anaerobic Gramnegative
bacteria were significantly
more susceptible to dhvar4 than
facultatively anaerobic or anaerobic
bacteria as a whole (p = 0.013 and
p = 0.018, for salivary bacteria, and
p = 0.021 and p = 0.020 for
plaque bacteria, respectively).
Although the oral bacteria are
protected by biofilm formation, the
synthetic histatin analog caused a
significant reduction of viable
counts in a model for oral biofilm
as well as in isolated oral biofilms.
Effect of histatin-derived basic antimicrobial peptides on oral biofilms
Helmerhorst EJ*, Hodgson R, van’t Hof W*, Veerman ECI*, Allison C and Amerongen AVN*
(*Academic Centre for Dentistry
(ACTA) Vrije University, Department
of Oral Biochemistry, van der
Boechorststraat 7, 1081,
Amsterdam)
J Dent Res 77: 3153 (special issue)
B 1998
Methods for Microscopic Characterisation of oral biofilms: analysis of colonization, microstructure and molecular transport phenomena
Singleton S, Treloar R, Warren P, Watson GK, Hodgson R, Allison C
Adv Dent Res 11(1) 133-149, April
1997
Assessment of the role of biofilm
microstructure in biofilm specific
activities requires non-destructive
measurement techniques for
parameterization of structural
characteristics in parallel with
relevant biochemical and
physiological data. This paper briefly
reviews some current methods for
biofilm structural analysis, with
emphasis on new developments in
optical imaging and mathematical
modeling methods. Fluorescence
imaging studies of bacterial
colonization events occurring on
exposed model tooth surfaces
indicated that bacterial adhesion to
sessile organisms was of central
importance to the early colonization
process and that this occurred in a
non random manner. Structural
studies of mature biofilms by
confocal microscopy demonstrated
the spatial distribution of individual
species using fluorescent
antibodies. Biofilms grown under
different physiological conditions
exhibited differences in structure,
and methods were developed for
parameterizing the spatial
orientations of the bacteria.
Diffusive processes within biofilm
microstructures were studied using
a random walk model in both 2 D
and 3 D Modeling of convective
flow within biofilm microstructures
was achieved by application of
lattice Boltzmann methodology.
Detection of pH gradients in biofilms using 2-photon excitation microscopy
Bradshaw DJ*, Marsh PD**, Gerritsen H***, Vroom J***, Watson GK and Allison C
(*PHLS, Centre for Applied
Microbiology and Research, Porton
Down, Salisbury, UK) (**Leeds
Dental Institute, Leeds LS2 9LU,
UK) (***University of Utrecht, The
Netherlands)
J Dent Res 77: 2854 , (special issue)
B 1998
Role of fusobacterium nucleatum and coaggregation in anaerobe survival in planktonic and biofilm oral microbial communities during aeration
Bradshaw DJ*, Marsh PD**, Watson GK and Allison C
(*PHLS, Centre for Applied
Microbiology and Research, Porton
Down, Salisbury, UK) (**Leeds
Dental Institute, Leeds, UK)
Infection and Immunity 66: (10)
4729-4732 1998
Coaggregation is a wellcharacterized
phenomenon by
which specific pairs of oral bacteria
interact physically. The aim of this
study was to examine the patterns
of coaggregation between
obligately anaerobic and oxygentolerant
species that coexist in a
model oral microbial community,
Obligate anaerobes other than
Fusobacterium nucleatum
coaggregated only poorly with
oxygen-tolerant species. In
contrast, F. nucleatum was able to
coaggregate not only with both
oxygen-tolerant and other
obligately anaerobic species but
also with otherwisenoncoaggregating
obligate
anaerobe-oxygen-tolerant species
pairs. The effects of the presence
or absence of F, nucleatum on
anaerobe survival in both the
biofilm and planktonic phases of a
complex community of oral
bacteria grown in an aerated (gas
phase, 200 ml of 5% CO2 in
air.min(-1)) chemostat system were
then investigated. In the presence
of F. nucleatum, anaerobes
persisted in high numbers (>10(7).ml(-1) in the planktonic
phase and >10(7).cm(-2) in 4-day
biofilms), In an equivalent culture in
the absence of F. nucleatum, the
numbers of black-pigmented
anaerobes (Porphyromonas
gingivalis and Prevotella nigrescens)
were significantly reduced (P less
than or equal to 0.001) in both the
planktonic phase and in 4-day
biofilms, while the numbers of
facultatively anaerobic bacteria
increased in these communities.
Coaggregation-mediated
interactions between F. nucleatum
and other species facilitated the
survival of obligate anaerobes in
aerated environments.
IMAGEM 8
Depth penetration and detection of pH gradients in biofilms by two-photon excitation microscopy
Vroom JM*, De Grauw KJ*, Gerritsen HC*, Bradshaw DJ**, Marsh PD***, Watson GK, Birmingham JJ and Allison C
(*University of Utrecht, The
Netherlands) (**PHLS, Centre for
Applied Microbiology and
Research, Porton Down, Salisbury,
UK) (***Leeds Dental Institute,
Leeds, UK)
Applied and Environmental
Microbiology 65: (8) 3502-35, 11
August 1999
Deep microbial biofilms are a major
problem in many industrial,
environmental, and medical
settings. Novel approaches are
needed to understand the structure
and metabolism of these biofilms.
Two-photon excitation microscopy
(TPE) and conventional confocal
laser scanning microscopy (CLSM)
were compared quantitatively for
the ability to visualize bacteria
within deep in vitro biofilms. pH
gradients within these biofilms
were determined by fluorescence
lifetime imaging, together with
TPE. A constant depth film
fermenter (CDFF) was inoculated
for 8 h at 50 ml.h(-1) with a
defined mixed culture of 10 species
of bacteria grown in continuous
culture. Biofilms of fixed depths
were developed in the CDFF for 10
or 11 days. The microbial
compositions of the biofilms were
determined by using viable counts
on selective and nonselective agar
media; diverse mixed-culture
biofilms developed, including
aerobic, facultative, and anaerobic
species. TPE was able to record
images four times deeper than
CLSM. Importantly, in contrast to
CLSM images, TPE images recorded
deep within the biofilm showed no
loss of contrast. The pH within the
biofilms was measured directly by
means of fluorescence lifetime
imaging; the fluorescence decay of
carboxyfluorescein was correlated
with biofilm pH and was used to
construct a calibration curve. pH
gradients were detectable, in both
the lateral and axial directions, in
steady-state biofilms. When
biofilms were overlaid with 14 mM
sucrose for 1 h, distinct pH
gradients developed.
Microcolonies with pH values of
below pH 3.0 were visible, in some
cases adjacent to areas with a
much higher pH (>5.0). TPE
allowed resolution of images at
significantly greater depths (as
deep as 140 mum) than were
possible with CLSM. Fluorescence
lifetime imaging allowed the in
situ, real-time imaging of pH and
the detection of sharp gradients of
pH within microbial biofilms.
Immunohistochemical study of bacterial distribution within oral biofilms
Shore RC*, Kirkham J*, Devine DA*, Marsh PD*, Nattress B*, Allison C and Robinson C*
(*Leeds Dental Institute, Leeds LS2
9LU, UK)
J Dent Res 2000, 79 (special issue)
2224-2224
Clinical Studies
The removal of dental plaque under timed intervals of toothbrushlng
Hodges CA, Bianco JG and Cancro LP
J Dent Res 1981, 60 (special issue),
425
The periodontal status of subjects receiving non-steroidal anti-inflammatory drugs
Waite IM*, Saxton CA, Young A**, Wagg BJ and Corbett M** (*University College Hospital Dental School, London) (**Royal National Orthopaedic Hospital, London)
J Periodontal Res 1981,16,
100-108
A test group of 22 subjects who
had been taking non-steroidal antiinflammatory
drugs for periods in
excess of one year were matched
with a control group of 22 office
workers with reference to age and
Plaque Index. It was found that the
test group had significantly lower
values of Gingival Index and
shallower depths of pockets than
the control group of subjects.
There was a trend also for there to
be less loss of attachment in the
test group. These results were
interpreted as indicating that antiinflammatory
drugs may influence
the response of the periodontal
tissues to plaque by reducing the
prostaglandin concentration in the
tissues. The slight decrease in loss
of attachment in the test group
may also be explained by the
reduction in prostaglandin synthesis
in the subjects taking antiinflammatory
drugs.
Inhibition of plaque growth by zinc salts
Harrap GJ, Saxton CA and Best JS J Periodontal Res 1983,18,
634-642
Certain metal salts inhibit the
growth of dental plaque.
The effect
of zinc salts was investigated
because of contradictory reports in
the literature. Using cultures of
human plaque, artificial dental
plaques were grown in vitro on
aluminium strips. The effect of
various zinc salts was examined by
treating the strips intermittently
with solutions of the salts during
the period of growth. The action of
mouthwashes containing zinc salts in vivo on plaque growth was
determined in human volunteers.
All the water-soluble zinc salts that
were tested gave a similar
concentration-dependent inhibition
of plaque growth in vitro. The
effectiveness of the treatment was
reduced by increasing the time
allowed for growth after the final
application of zinc. Solutions of
zinc (17-19mM) as the citrate or
phenolsulphonate salt, gave about
30% reduction in the extension of
plaque along the gingival margin in vivo over 16 hours. Subjects with
high rates of plaque growth with
the placebo mouthwash were most
affected by zinc salts. Increasing
the zinc concentration to 30mM
did not further increase the activity.
Previous reports of low activity of
zinc against plaque growth in vivo are explained by too low a
concentration of zinc or too low a
frequency of application. The
results confirm that zinc salts,
including zinc citrate, inhibit the
growth of plaque in vivo and in vitro.
Human oral retention of zinc from mouthwashes containing zinc salts and its relevance to plaque control
Harrap GJ, Best JS and Saxton CA
Arch Oral Biol 1984, 29, 87-92
Subjects using 30mM zinc
phenolsulphonate as a mouthwash
retained 12% of the zinc. Salivary
zinc concentration was increased
by using mouthwashes containing
17-35mM zinc as the sulphate,
phenolsulphonate or citrate. For
17mM zinc sulphate or
phenolsulphonate, the effect lasted
three to four hours. Zinc retained in
the mouth gave visible fluorescence
after rinsing with
8-hydroxyquinoline and was
particularly evident on the tongue,
cheek mucosa and dental plaque.
The concentration of zinc in plaque
was increased 13-19 fold one hour
after using 31 or 18mM zinc
phenolsulphonate. A three fold
increase was still present six hours
later for the 31mM mouthwash.
Zinc salts inhibited acid production
from [14C]-glucose in vitro by
plaque at concentrations which
were found in plaque in vivo after
using the mouthwashes. The effect
of zinc on the metabolic activity of
plaque may reduce the growth rate
of plaque bacteria and so decrease
plaque growth.
Influence of mechanical aspects of dentifrice and toothbrush in plaque control
Cancro LP, Pader M, Birenz SS and Spanedda PP J Soc
Cosmet Chem 1985, 36, 377
The effect of dentifrices containing zinc citrate on plaque growth and oral zinc levels
Saxton CA, Harrap GJ and Lloyd AM J
Clin Periodontol 1986,13,
301-306
Zinc salts have previously been
shown to possess antiplaque
activity in solution but this activity
has as yet not been reported for
dentifrices. The purpose of the
present investigation was to
establish the effect of dentifrices
containing zinc citrate (ZCT) on
plaque growth and on the
concentration of zinc in saliva and
plaque. Plaque growth inhibition
was studied over periods of time
approximating to intervals for
normal oral hygiene procedures.
Zinc in saliva and plaque was
measured by atomic absorption
spectroscopy.
Elevated zinc levels in saliva were
observed for 3-4 hours after
brushing with the zinc citrate
dentifrice. Similarly, raised levels of
zinc were encountered in plaque
one hour following contact with a
slurry of a dentifrice containing
ZCT. Increased concentrations of
zinc were observed in plaque fluid
and plaque residue.
The plaque growth data from
88 participants in five studies
revealed that plaque regrowth over
16 hours or 22 hours was reduced
by dentifrices containing 0.5 per
cent ZCT, compared with placebo
dentifrices. Dentifrices which contained 0.5 per cent ZCT or 0.4
per cent stannous fluoride, had
similar inhibitory effects on plaque.
Further analysis of the data showed
that subjects with high rates of
plaque growth benefited more
from the zinc dentifrices than those
with low rates of plaque growth. It
is suggested that the effect on
plaque was related to zinc
concentration in the dentifrice
rather than total dose applied and
that the main effect of zinc was to
inhibit the extension of existing
plaque.
The effects of a dentifrice containing zinc citrate and 2,4,4-trichloro-2’- hydroxydiphenyl ether
Saxton CA
J Periodontol, 1986, 57, 555-561
The effects of a dentifrice which
contained 1% zinc citrate and
0.5% of a non-ionic antimicrobial
agent 2,4,4’-trichloro-2’-
hydroxydiphenyl ether on plaque
and gingival health have been
investigated. In a four day
nonbrushing study in which
dentifrices were used as slurries,
this dentifrice inhibited plaque
accumulation significantly more
than dentifrices which contained
either zinc citrate or Triclosan
separately. In a 28 day double-blind
cross-over study, a significant
reduction in plaque accumulation
and improvement in gingival health
was demonstrated with a group of
well motivated volunteers who had
a good standard of oral health.
Analysis of the data suggested that
the benefit might be extended to a
less motivated population.
Changes in periodontal health in a cohort of British workers over a fourteen year period
Sheiham A*, Smales FC** Cushing AM*** and Cowell CR (*University College London and the London Hospital Medical College) (**The London Hospital Medical College) (***King’s College Dental School)
Brit Dent J 1986, 160, 125-127
In a longitudinal study of
periodontal diseases lasting 14
years, in 89 British industrial
workers with a mean age of 40
years at the initial examination, it
was found that the level of
periodontal disease had decreased.
The periodontal index decreased by
26% from 4.09 in 1966 to 3.01 in
1980. A similar decrease of 26.5%
and 22.8% respectively occurred
also in those people who were
below and those above 40 years of
age in 1966. The debris index
decreased by 148% from 1.08 to
0.92, and the calculus index from
1.18 to 0.65 – a 44.9% reduction.
The findings suggest that although
a large percentage of teeth are
being extracted as people age, the
severity of periodontal disease and
oral cleanliness is improving
markedly.
Plaque and gingivitis reduction by zinc citrate and Triclosan dentifrices
Saxton CA, Svatun B*, Lane RM and van der Ouderaa FJG (*Department of Pedodontics, University Dental School, Oslo, Norway) J Dent Res, 1986, 65 (special issue),
787
Effect of Triclosan/zinc citrate toothpaste on oral flora
Jones CL, Prottey C and Ritchie JA
J Dent Res 1986, 65 (special issue),
818
Effect on plaque accumulation of a mouthwash containing, sodium lauryl sulphate
Pretara-Spanedda P, Cancro LP, Pader M and Jacobs D
J Dent Res 1986, 65 (special issue),
788
Anticalculus activity of 0.5 per cent zinc citrate trihydrate in dentifrices
Best JS, Harrap GJ Johnson AW and Langmead HR
J Dent Res 1987 (special issue),
66,191
The effects of a dentifrice containing a zinc salt and a non-cationic antimicrobial agent on plaque and gingivitis
Saxton CA, Lane RM and van der Ouderaa F
J Clin Periodontol 1987,14,
144-148
The antiplaque potential of metal
salts in mouthwashes or dentifrices
has been previously demonstrated.
The purpose of the present
investigation was to establish the
effects on plaque and gingival
health of a dentifrice which
contained a combination of the
metal salt, zinc citrate and the
antimicrobial agent, Triclosan.
Plaque growth was reduced by a
dentifrice which contained either
zinc citrate or Triclosan but greater
inhibition was achieved with
dentifrices which contained both
agents. A four-day non-brushing
study in which slurries of the
dentifrice were used confirmed
that the test dentifrice which
contained 1% zinc citrate and
0.5% Triclosan reduced the
accumulation of plaque by 50%. In
a double-blind crossover study of
28 days duration, a significant
reduction in plaque accumulation
and an improvement in gingival
health was demonstrated for the
test dentifrice compared to the
placebo. Further analysis of the
data indicated that the dentifrice
was most efficacious for
participants who brushed
ineffectively. Also, the greatest
benefit was obtained by subjects
that used the largest amount of
dentifrice.
The influence of a dentifrice containing a zinc salt and a nonionic antimicrobial agent on the maintenance of gingival health
Svatun B*, Saxton CA, van der Ouderra F and Rölla G* (*Department of Pedodontics, Faculty of Dentistry, University of Oslo, Oslo, Norway)
J Clin Periodontol 1987,14,
457-461
The purpose of the present
investigation was to test the
concept that a dentifrice containing
zinc citrate and Triclosan could
maintain gingival health. The
gingival health of 101 young
predominantly female student
nurses in Oslo was brought to a
high level by professional cleaning
supported by oral hygiene
instruction. The criterion of gingival
health was 5 elicited bleeding sites
from a full mouth assessment. The
mean bleeding value attained for
the whole group was 3.5. Two
balanced groups were formed,
based on the initial number of
elicited bleeding sites and plaque
values. One group used the test
dentifrice and the other group the
placebo for six months, with an
intermediate assessment after three
months. The placebo group failed
to maintain the standard of oral
hygiene and gingival health that
had been achieved by professional
care. In contrast, the group using
the test dentifrice for six months
exhibited similar levels of plaque
and gingival health to that
observed at baseline following oral
hygiene instruction. After six
months, <7% of the subjects in the
placebo group possessed healthy
gingivae in contrast to 60% of the
test group. Thus a dentifrice
containing a zinc salt and nonionic
germicide had successfully
maintained gingival health in a
group of young adults.
The oral retention and antiplaque efficacy of Triclosan in human volunteers
Gilbert RJ and Williams PEO* (*Simbec Research Ltd, Merthyr Tydfil, Mid Glamorgan CF48 4DR)
Br J Clin Pharmac 1987, 23,
579-583
The delivery of the antibacterial
agent, Triclosan (2,4,4’ trichloro-2’-
hydroxy diphenyl ether) to the
mouth during toothpaste use was
investigated. An antiplaque
toothpaste containing 0.2%(w/w)
Triclosan significantly inhibited
overnight plaque growth in 12
human volunteers and Triclosan
was present in bacterial plaque for
at least eight hours after dosage
and in the oral mucosa for at least
three hours.
In vivo anticalculus effect of a dentifrice containing 0.5 per cent zinc citrate trihydrate
Stephen KW* Burchell CK, Huntington E, Baker AG, Russell Jl* and Creanor SL* (*Department of Oral Medicine and Pathology, University of Glasgow Dental Hospital and School, Glasgow, UK)
Caries Res 1987, 21, 380-384
The effects on supragingival
calculus of dentifrices containing
0.5 per cent zinc citrate trihydrate
(ZCT) measured in a clinical trial is
presented. The trial was carried out
in Lanarkshire, UK, on a panel of
3000 children
The results demonstrate the
anticalculus effects of toothpastes
containing sodium
monofluorophosphate 0.5%ZCT
over a three year period.
Oral disposition of Triclosan (2,4,4’-trichloro-2’- hydroxydiphenyl ether) delivered from a dentifrice
Gilbert RJ, Fraser SB and van der Ouderaa FJG
Caries Res 1987 21, 29-36
This paper reports measurements
of oral retention and intra-oral
distribution of Triclosan in man
after use of an antiplaque
toothpaste slurry containing this
antibacterial. Determinations of
Triclosan were made by highperformance
liquid
chromatography. It was shown that
38%of the Triclosan in a
1g dose of toothpaste (0.50% w/w
Triclosan) and 62% of a 3g dose
was retained. Triclosan was
detected and measured in plaque
and this antibacterial was also
present in saliva. Levels of
approximately 20-30µg Triclosan/ml
of saliva were measured five
minutes after toothpaste use and
these had fallen to approximately
3-4µg/ml two hours later. A
significant inhibition of plaque acid
production is shown to follow use
of the antiplaque dentifrice.
Plaque inhibition by hexetidine and zinc
Giertsen E* Svatun B* and Saxton A (*Department of Pedodontics, University Dental School, Oslo, Norway)
Scand J Dent Res 1987, 95,
49-54
Rinsing experiments with
mouthwashes containing zinc ions,
hexetidine and a combination of
hexetidine and zinc ions were
performed with a group of ten volunteers. The amount of plaque
was assessed after rinsing with the
test solutions for four days during
which mechanical toothcleaning
was discontinued. Significantly
improved inhibition was observed
by the combination of hexetidine
and zinc ions compared with the
two agents used separately. In vitro bacteriological tests showed that
hexetidine and zinc ions had a
synergistic inhibitory effect on the
growth of streptococcus mutans..
IMAGEM 9
The oral clearance of zinc and Triclosan after delivery from a dentifrice
Gilbert RJ
J Pharm Pharmacol 1987, 39,
480-483
Oral delivery and retention of zinc
and Triclosan were measured in
man after use of an anti-plaque
dentifrice containing these
antibacterial agents. Triclosan (25%
of the dose) and zinc (24%) were
retained in the mouth immediately
after toothbrushing and a single
mouthrinse. Salivary concentrations
fell from 7.5µg g–1 (Triclosan) and
7.0µg g–1 (zinc) after five minutes
to 0.5µg g–1 (Triclosan) and 1.2µg
g–1 (Triclosan) and 1.2µg g–1
(zinc), two hours after brushing.
Relative ability of three dentifrices and a mouthrinse to control plaque
Pretara-Spanedda P, Beiermeister S, Hubbard S and Cancro LP
J Dent Res 1987, 66 (special issue),
258
Maintenance of oral health by unsupervised use of a dentifrice containing zinc and non ionic anti-bacterial
Svatun B*, Rolla G*, Saxton CA and van der der Ouderaa FJG (*Department of Pedodontics, University Dental School, Oslo, Norway)
J Dent Res 1987, 66 (special issue),
279.
Influence of a dentifrice containing zinc citrate and Triclosan on plaque
Saxton CA, Gilbert RJ and Svatun B* (*Department of Pedondontics, University Dental School, Oslo, Norway)
Caries Res 1987, 21,188
Changes in the oral flora during longitudinal oral ecology studies
Jones CL and Prottey C
Caries Res 1987, 21,164
Two year effect of stated brushing frequency on plaque gingivitis and caries increments in teenagers
Burchell CK, Stephen KW*, Creanor SL* and Russell Jl* (*University of Glasgow Dental School, Glasgow, UK)
Caries Res 1987, 21,185
In vivo anticalculus effect of a dentifrice containing 0.5% zinc citrate trihydrate
Stephen KW*, Burchell CK, Huntington E, Baker AG, Russell JI* and Creanor SL* (*Department of Oral Medicine and Pathology, University of Glasgow Dental Hospital and School, Glasgow, UK)
Caries Res 1987, 21, 380-384
Anti plaque agents are known to
reduce calculus formation and a
quantitative relationship has been
found between stainable plaque
and calculus. Three thousand
children from the 1st grade in 12
secondary schools participated in a
study on the effects of 0.5% zinc
citrate (ZCT), in a dentifrice, on
supragingival calculus. At the final
examination 2316 children were
present. The reduction in calculus
prevalence due to ZCT was
equivalent to 30% of the placebo
calculus presence (p<0.001). It was
also found that in the group of 277
children who had received a dental
prophylaxis prior to the final three
year examination there was less
calculus present in children using
ZCT (p<0.05). It can be concluded
that the results demonstrate the
anticalculus effect of toothpastes
containing sodium
monofluorophosphate and 0.5%
ZCT over a three year period.
The effect on the oral flora of long-term exposure to a zinc citrate toothpaste
Jones CL and Stephen KW* (*University of Glasgow Dental School, Glasgow, UK)
Caries Res 1988, 22,101-102
Use of zinc containing dentifrice: uptake of zinc by hydroxyapatite and by dental calculus
Ingram GS, Tan-Walker R, Gilbert RJ and van der Ouderaa FJG
J Dent Res 1988, 67 (special issue),
402
The oral disposition of zinc following the use of an anticalculus toothpaste containing 0.5 per cent zinc citrate
Gilbert RJ and Ingram GS
J Pharm Pharmacol 1988, 40, 399-
402
Zinc is retained in the mouth after
use of a toothpaste containing
0.5% zinc citrate. More than one
third of the dose was found to be
retained after normal brushing.
Elevated zinc levels were also found
in plaque. Saliva zinc levels were
significantly above background for
at least two hours after brushing. In vitro experiments demonstrated
that zinc can bind to the pelliclecoated
tooth surface and can
subsequently desorb into saliva.
Plaque can calcify to form calculus
containing appreciable levels of
hydroxyapatite. Zinc adsorbs to
hydroxyapatite inhibiting crystal
growth. Levels of zinc in plaque
were found to be considerably
higher than those taken up by
hydroxyapatite in an in vitro test of
crystal growth inhibition indicating
the potential of zinc to inhibit
calculus formation.
Clinical evaluation of a zinc citrate containing anti-calculus dentifrice
Kazmierczak M*, Mather ML, Ciancio SG, Fischman S*, and Cancro LP (*Center for clinical studies SUNY
at Buffalo)
J Dent Res 1988 67 (special issue)
246
Antiplaque effects and mode of action of a combination of zinc citrate and a non-ionic antimicrobial agent
Saxton CA, Svatun B* and Lloyd AM (*Department of Pedodontics, Oslo University Dental School, Oslo, Norway)
Scand J Dent Res 1988, 96,
212-217
The effect upon plaque growth of
adding a non-ionic antimicrobial
agent, Triclosan, to a dentifrice
containing zinc citrate was
established in short-term in vivo studies. Plaque regrowth was
inhibited by brushing with
dentifrices which contained either
zinc citrate or Triclosan. When both
were combined in the same
dentifrice, the inhibition of
overnight plaque regrowth was
significantly greater. In two fourday
nonbrushing studies, the
dentifrices containing both zinc
citrate and Triclosan were applied
either undiluted by the use of a
cap splint or as 23% suspensions in
water. Both methods resulted in
significant reductions in plaque
accumulation, with the greater
activity being observed for the
undiluted application of the
dentifrice. Analysis of results of the
overnight plaque studies for
individual teeth revealed that the
two agents had a complementary
inhibitory action on plaque
regrowth, zinc citrate being more
effective on existing plaque
whereas Triclosan inhibited plaque
formation on clean surfaces. The
dentifrice containing both agents
was effective against both existing
plaque and new plaque formation.
It is concluded that the addition of
Triclosan to a dentifrice containing
zinc citrate improves its antiplaque
potential.
The effect of long-term use of a dentifrice containing zinc citrate and a non-ionic agent on the oral flora
Jones CL, Ritchie JA, Marsh PD* and van der Ouderaa FJG (*Bacterial Metabolism Research Laboratory, PHLS Centre for Applied Microbiology and Research, Porton Down, Salisbury SP4 0KG, UK)
J Dent Res 1988, 67, 46-50
The effect on the oral ecology of
daily use, for seven months, of a
dentifrice containing 0.5% (w/w)
zinc citrate and a non-ionic agent, i
e., 0.2% (w/w) Triclosan (2,4,4’-
trichloro-2’-hydroxydiphenyl ether),
has been monitored on 13 adult
volunteers. Plaque and saliva were
sampled monthly and the bacterial
flora analysed. Twenty-six
volunteers used a placebo
dentifrice as part of their normal
oral hygiene for four months to
establish the baseline microbial
flora. The volunteers were then
split into two equal groups: One
group continued to use the
placebo dentifrice; the other used
the dentifrice containing zinc
citrate and Triclosan. There was no
evidence that seven months use of
a dentifrice containing 0.5% zinc
citrate and 0.2% Triclosan caused
shifts in the oral microbial ecology,
nor was there any evidence of
developing bacterial resistance to
Triclosan.
Long-term exposure of plaque to zinc citrate
Jones CL, Stephen KW* Ritchie JA, Huntington E, Saxton CA and van der Ouderaa FJG *Department of Oral Medicine and Pathology, University of Glasgow Dental School, Glasgow, UK)
Caries Res 1988, 22, 84-90
The effect of three years
continuous exposure to dentifrices
containing different levels of
sodium monofluorophosphate,
with or without 0.5% zinc citrate
has been investigated on plaque
growth inhibition. Additionally,
changes in the plaque microflora
during prolonged exposure to zinc
have been monitored in children
with high or low caries increments.
Following long-term use the
inhibitory effect of zinc citrate on
plaque growth was fully
maintained. There was no evidence
that prolonged exposure to zinc
caused shifts in the plaque
population of streptococcus mutans, streptococcus sanguis, lactobacilli, or actinomyces species.
A positive association was observed
between children with high caries
increments and high numbers of streptococcus mutans in plaque
and saliva. Caries increments were
also associated with total viable
count per microgram plaque
protein. A negative association was
observed between combined caries
increment and number of streptococcus sanguis in plaque.
The control of gingivitis and calculus by a dentifrice
Saxton CA, Jones CL and Ritchie JA J Dent Res 1989, 68, 971
Comparison of the rate of calculus formation in an Asian and Caucasian population
Gaare D*, Rölla G* and van der Ouderaa F (*Department of Pedodontics, University Dental School, Oslo, Norway)
Caries Res 1989, 23, 104
The effect of zinc citrate dentifrices on the development of gingivitis
Saxton CA and Cummins D
J Dent Res 1989, 68, 971
Effect of a dentifrice containing zinc and Triclosan on gingivitis
Jones CL, Saxton CA and Ritchie JA
J Dent Res 1989, 68, 971
The reduced development of gingivitis after the use of dentifrice
Saxton C
A J Dent Res 1989, 68, 565
Delivery of zinc and Triclosan to oral micro-reservoirs of antibacterial activity
Gilbert RG, Tan Walker RLB and van der Ouderaa FJG
J Dent Res 1989, 68, 1706-1717
Oral delivery of zinc from slurries and separated supernatant fractions of dentifrices
Tan Walker RLB and Gilbert JA
J Dent Res 1989, 68, 1706
Maintenance of gingival health by a dentifrice containing zinc citrate and Triclosan
Saxton CA
J Dent Res 1989, 68, 1724-1726
One-year study of the efficacy of a dentifrice containing zinc citrate and Triclosan to maintain gingival health
Svatan B*, Saxton CA, Rölla G and van der Ouderaa F (*Department of Pedodontics, University Dental School, Oslo, Norway)
Scand J Dent Res 1989, 97,
242-6
In a previous study we
demonstrated that gingival health
could be maintained in a group of
highly motivated nurses using a
dentifrice containing a zinc salt and
Triclosan. We have now
investigated the effect of the
experimental dentifrice on a group
of less motivated men. One
hundred and three male students
were given oral hygiene instruction
(OHI) and their teeth were
professionally cleaned. For each
individual, both the instruction and
cleaning were completed in a
single 15-minute period. Two
balanced groups were formed,
based on the prestudy plaque level
and gingival bleeding. One group
used the experimental dentifrice for
12 months, while the other used a
control. Results were assessed after
6 months, and after 12 months. As
a result of the OHI, plaque and
gingival bleeding were reduced at
the end of the pre-study period.
This improvement was not
maintained by the control group
even for six months. In contrast,
the test group exhibited
significantly lower plaque level and
higher standard of gingival health
throughout the 12 months.
Reassessment of available
participants six months after the
study showed that gingival health
in both groups had returned to its
pre-study condition. The lower
observed standard of gingival
health in the test group after
ceasing to use the experimental
dentifrice further supports the
conclusion that this dentifrice can
contribute to an oral care
programme.
Comparison of the rate of formation of supragingival calculus in an Asian and a European population
Gaare D*, Rolla G* and van der Ouderaa F (*Faculty of Dentistry, University of Oslo, Norway)
Recent Advances in the Study of
Dental Calculus 1989 IRL Press,
115-122
A comparison of formation rate of
calculus was performed between
74 male students in Oslo and 77
soldiers in Jakarta of the same age.
It was found that the formation
rate was higher in the Asian
population and that more teeth
acquired calculus, in this group.
The difference in formation rate
was not caused by age, sex,
toothbrushing frequency or
toothpaste abrasivity. It is
suggesting that differences in
eating habits and food may
account for the difference. In
particular consumption of rice
which contains silicon and which
has a low abrasivity may be a
significant factor in the high
formation rate in the Asian group.
A one-year study on the maintenance of gingival health by a dentifrice containing a zinc salt and non-anionic antimicrobial agent
Svatun B*, Saxton CA, Rolla G* and van der Ouderaa F (*Department of Pedodontics, Faculty of Dentistry, University of Oslo, Norway)
J Clin Periodontol 1989, 16, 75-80
An experimental dentifrice
containing zinc citrate and Triclosan
was used by student nurses for 12
months without supervision, while
a corresponding group used a
control dentifrice. Dental flossing
was not permitted during the first
six months. Gingival health
achieved in a pre-experimental
period, during which oral hygiene
instruction was given, was
maintained by users of the
experimental dentifrice for 12
months but not by users of the
control dentifrice. About one third
of the control group used floss
daily during the second six months
and significantly improved their
gingival health to a level
comparable to that of the
experimental group. Flossing
brought no extra benefit for the
latter group. In the control group,
approximal regions were less
healthy than buccal or lingual sites.
The gingival health of these sites
improved significantly with daily
flossing. The experimental
dentifrice maintained gingival
health in all sites irrespective of the
use of floss. The study has
confirmed that oral health can be
maintained by the use of the
experimental dentifrice for at least
12 months in a habitual
toothbrushing regime, and that the
dentifrice would be as effective and
simpler than relying on the
combination of brushing and
regular flossing.
The effect of a dentifrice containing zinc citrate and Triclosan on developing gingivitis Saxton CA and van der Ouderaa FJG J Periodont Res 1989, 24, 75-80
A partial mouth experimental
gingivitis model was employed to
establish the potential efficacy of a
dentifrice containing a zinc salt and
the antimicrobial agent Triclosan to
prevent or delay the development
of gingivitis over a period of 28
days. Initially, gingival health was
established in 34 subjects following
a six-week period of professional
tooth cleaning and oral hygiene
instruction. A toothshield was
constructed to fit four posterior
mandibular teeth. Undiluted test or
placebo dentifrice was applied to
the experimental teeth via the
toothshield, which also prevented
plaque removal from these teeth
during habitual brushing of the
remainder of the dentition. The
presence of plaque, bleeding after
probing and visual signs of
inflammation were independently
assessed. Plaque accumulated
rapidly and gingivitis developed in
both groups. At the two-week
assessments lower mean plaque
scores were recorded for the group
using the test dentifrice. At the
four-week assessment a
significantly lower level of gingivitis
was recorded for the test group. It
is concluded that (a) the model can
be used to establish the potential
efficacy of a dentifrice to maintain
gingival health (b) the dentifrice
containing zinc citrate and Triclosan
was efficacious and (c) the Gingival
Index possibly overestimates the
proportion of healthy gingival sites. A
dentifrice to control gingivitis and calculus Svatun BL* and Saxton CA (Department of Pedodontics, University Dental School, Oslo, Norway) J Dent Research 1990, 69 (special
issue) 165
Microbiological and clinical effects of a dentifrice containing zinc citrate and Triclosan in the human experimental gingivitis model Jones CL, Saxton CA and Ritchie JA J Clin Periodontol 1990, 17,
570-574
A partial mouth experimental
gingivitis model was employed to
establish the effect of a dentifrice
containing 0.2% Triclosan and
0.5% zinc citrate on the
development of chronic gingivitis.
In addition, changes in the plaque
flora associated with the
developing gingivitis have been
monitored. Following a period of
stringent oral hygiene, volunteers
were allocated to one of two
treatment groups. A toothshield
was constructed to fit four
posterior mandibular teeth. During
the 21day experimental period test
or placebo dentifrice was applied
to the experimental teeth via the
tooth shield. The toothshield also
prevented plaque removal from
those teeth during habitual
brushing of the remaining
dentition. Supragingival plaque was
collected at baseline and day 21 for
analysis of the total bacterial flora.
At the end of the experimental
period, plaque and gingivitis had
developed in both groups.
However, the test group had
significantly less plaque and
gingivitis than the placebo group.
The microbiological data
demonstrated that plaque from the
test group contained significantly
lower numbers of anaerobes
compared to plaque from the
placebo group. This was considered
particularly significant as these
bacteria are generally associated
with chronic inflammatory
periodontal disease. There was also
a trend for the numbers of actinomyces to decrease in plaque
from the test group but not in the
placebo group.
Six month study of the effect of a dentifrice containing zinc citrate and Triclosan on plaque, gingival health, and calculus Svatun B*, Saxton CA and Rölla G* (*Department of Pedodontics, Faculty of Dentistry, University of Oslo, Olso, Norway) Scand J Dent Res 1990, 98,
301-304
In two previous studies gingival
health was maintained for at least
12 months by a dentifrice
containing zinc citrate and
Triclosan. The aims of the present
study were to determine if a
zinc/Triclosan dentifrice would
stabilize gingival health if a lower
concentration of zinc was used and
to investigate its effect on the
formation of calculus. One hundred
and one men and women were
given oral hygiene instruction and
their teeth were professionally
cleaned. Two balanced groups
were then formed, based on the
pre-study levels of gingival bleeding
and calculus. One group used the
zinc/Triclosan dentifrice for six
months, while the other used a control. Results were assessed after
three months and six months.
Following the oral hygiene
instruction, plaque and gingival
bleeding were assessed at the end
of the four week period preceding
the experimental phase, and both
had been reduced. This
improvement was not maintained
by the control group, whereas the
test group exhibited significantly
lower plaque levels and a higher
standard of gingival health
throughout the six months. After
three months, levels of calculus in
the control group had returned to
pre-study levels. At both the three
and six-month assessments,
significantly less calculus was
observed in the test group. The
improved plaque control, stabilized
gingival health, and reduced
calculus formation support the
conclusion that a dentifrice
containing 0.5% zinc citrate and
0.2% Triclosan can contribute to
oral care.
IMAGEM 10
Concentration of anti-microbial proteins in human Saliva
Page DJ, Gilbert RJ, Bowen WH* and Stephen KW** (*Department of Dental Research, University of Rochester Medical Centre, NY, USA) (**University of Glasgow Dental School, Glasgow, UK)
Caries Res 1990, 24, 216-219
This paper reports data on the
salivary concentrations of some
proteins which exhibit antimicrobial
activity, i.e. lysozyme, lactoferrin,
salivary peroxidase and
immunoglobulin A and the oral
health of 198 school children aged
14. The effect of three years
continuous usage of a 0.5% zinc
citrate dentifrice on the salivary
concentrations of these proteins is
also reported. This study was
carried out during a three year
clinical trial. The dentifrices with or
without zinc citrate were:Lysozyme
2.39±0.31µg/ml with (Zn),
2.10±0.29µg/ml (without Zn);
lactoferrin 4.90±0.52µg/ml,
5.72±0.66µg/ml; salivary
peroxidase 0.245±0.015
Absorbance unit/min/ml,
0.248±0.012 Absorbance
unit/min/ml; immunoglobulin A
32.0±3.4µg/ml, 38.5±3.8µg/ml and
total protein 1.05±0.03mg/ml,
1.1±0.03mg/ml. None of these
antimicrobial proteins showed any
significant correlations with caries
increments (over a three year
period), caries score, gingival index
or oral hygiene. Total protein in
stimulated saliva significantly
correlated with oral hygiene only at
the p<0.05 level. The study showed
that prolonged use of a 0.5% zinc
citrate dentifrice does not affect
the salivary concentrations of these
proteins which make up part of the
non-specific salivary antimicrobial
defence system.
Improvement in gingival health by toothbrushing in individuals with large amounts of calculus
Gaare D*, Rolla G*, Aryadi RJ** and van der Ouderaa FJG (*Department of Pedodontics, University of Oslo, Norway) (**University of Indonesia, Jakarta, Indonesia)
J Clin Periodontol 1990, 17, 38-41
Dental calculus itself is not thought
to affect gingival health, but its
rough and porous surface retains
plaque better than a calculus-free
surface. In a population with a high
degree of supragingival calculus, the
effect of toothbrushing after a
careful professional prophylaxis
(group A) has been compared with
the effect of toothbrushing as the
sole oral hygiene aid (group B). The
subjects in this comparison were
Indonesian soldiers 20-25 years of
age, none of whom had
pathological pockets (CPITN 2) but
all had large amounts of calculus.
They had no experience of modern
oral hygiene practice but were given
individual instruction in
toothbrushing at the start of the
study and were provided with
toothpaste and toothbrush. Removal
of calculus in group A took an
average of one hour per subject by
an experienced clinician. Gingival
health in both groups improved after
two months: group A from 63% to
34% bleeding points and group B
from 61% to 36%. There was thus
no obvious benefit from the
professional prophylaxis received by
group A. The results are particularly
relevant for populations in which
professional prophylaxis is not
normally available. However, they
were obtained in a group of young,
healthy individuals and may not be
extrapolated to older and less
healthy populations or to individuals
with deep periodontal pockets. The
improvement of gingival health
through toothbrushing, in spite of
the presence of calculus, supports
the contention that plaque, rather
than calculus as a non-inflammatory
scale provides the pathogenic
potential.
IMAGEM 11
Control of gingivitis and calculus by a dentifrice containing a zinc salt and Triclosan Stephen KW*, Saxton CA, Jones CL, Ritchie JA and Morrison T (*University of Glasgow Dental School, Glasgow) J Periodontol 1990, 61, 674-679
The effect of unsupervised
brushing with a dentifrice
containing two antiplaque agents,
0.5% zinc citrate and 0.2%
Triclosan, on gingival health,
plaque, supragingival calculus, and
the oral flora was compared to
brushing with a non-active control
dentifrice. Volunteers were given
oral hygiene instruction and their
teeth were professionally cleaned.
They then used a placebo dentifrice
for a pre-experimental phase of
one month, before being stratified
into two groups on the basis of
their initial plaque, gingival
bleeding, and calculus levels, sex,
and age. Over the following 6
months, one group used the
control while the other used the
test dentifrice. Plaque levels,
gingival bleeding, and calculus
were assessed at baseline and at 3
and 6 months. Supragingival
plaque was sampled for
microbiological analysis at the
initial examination, at three and six
months (conclusion of study
period) and three months after the
study. Representative oral bacteria
and the development of bacterial
resistance to Triclosan were
monitored. Results showed that
plaque was reduced and gingival
health significantly improved during
the one-month pre-experimental
period. During the experimental
period, this improvement was not
maintained by the control group as
gingival bleeding and calculus
increased. In contrast, gingival
bleeding and calculus levels of the
test group were maintained
significantly below those of the
placebo group. Plaque levels were
lower in the test group after three
and six months, but the groups
were not significantly (P=0.05)
different. No shifts in oral flora or
development of bacterial resistance
to Triclosan were detected.
Effect of dentifrice dilution on developing plaque and gingivitis Putt MS*, Saxton CA, Milleman JL* and Kleber CJ (*Department of Chemistry, Indiana-Purdue University, Fort Wayne, Indiana, USA) J Dent Res 1991, 70, 32
Concentration of antimicrobial proteins in human saliva. Effect of six month usage of an antiplaque dentifrice on levels of antimicrobial proteins in unstimulated saliva from 102 adults Turner GA, Saxton CA and Svatun B* (*Department of Pedodontics, Faculty of Dentistry, University of Oslo, Norway) J Biol Buccale 1991, 19, 267-270
Student nurses (aged 20-26 years)
were assigned to two groups that
were matched for plaque levels and
gingival health. For six months,
one group used a standard fluoride
dentifrice while the other used an
identical dentifrice to which zinc
citrate (1%w/w) and Triclosan
(0.2%w/w) had been added. Levels
of natural antimicrobial proteins
(Iysozyme, lactoferrin, salivary
peroxidase and Immunoglobulin A)
in whole, unstimulated saliva taken
from the students at the start and
on completion of the six months
were measured. No statistically
significant differences were found
in the levels of antimicrobial
proteins in saliva between the test
and placebo groups. Review of the clinical effects of dentifrices containing Triclosan Gjermo PE* and Saxton CA (*Department of Periodontology, University Dental School, Oslo, Norway) Recent advances in Periodontology
II Eds: Gold SI, Midda M and
Mutlu S
Excerpta Medica Amsterdam
1991,151-159
This review looks at the effect of
some antibacterial dentifrices on
plaque and gingivitis. The focus is
on two recently introduced
dentifrices with Triclosan as the
active ingredient. One aims at
providing a slow release reservoir
of Triclosan in the oral cavity.
Three-month results indicate a
modestly improved effect on
plaque and gingivitis. The other
dentifrice on the market utilises the
principle of additive effects by
combining Triclosan and zinc
citrate. The combination appears to
be more effective than either
compound alone. Studies of up to
one year duration indicate that the
level of oral hygiene and gingival
health obtained through an initial
period of motivation and oral
hygiene instruction can be
maintained by the test dentifrice,
while most subjects in the control
group returned to pre-experimental
levels. It is concluded that the new
approaches to chemical plaque
control may be beneficial to the
population at large, and thus of
great clinical relevance.
The effect of zinc citrate and Triclosan on the control of plaque and gingivitis: short term clinical and mode of action studies Cummins D Recent advances in Periodontology
II Eds: Gold SI, Midda M and Mutlu
S Excerpta Medica Amsterdam
1991,
137-142
The rationale for the use of
antimicrobial/anti-plaque agents to
control supragingival plaque
formation and to prevent the onset
of early periodontal disease is clear.
In principle, toothpastes provide an
excellent vehicle for the delivery of
such agents. However, very few
have been successfully formulated
to give clinically active products.
A dentifrice formulation based
upon the additive anti-plaque
effects of low levels of zinc citrate
and Triclosan has been developed,
which is carefully optimised with
respect to delivery and clinical
activity. Short term clinical,
microbiological mode of action and
oral delivery studies give additional
confidence that the combined use
of these agents will result in
consistent anti-plaque activity during extended use and, hence,
will give rise to long term gingival
benefit.
Zinc citrate/Triclosan: A new anti-plaque system for the control of plaque and the prevention of gingivitis: Short term clinical and mode of action studies
Cummins D
J Clin Periodontol 1991, 18,
455-461
A dentifrice based upon the
additive anti-plaque effects of zinc
citrate and Triclosan has been
developed and optimised for
clinical activity. In 1-6h and fourday
plaque growth inhibition
studies, zinc citrate/Triclosan
inhibited plaque accumulation
significantly more than either agent
alone. The effect on the
development of gingivitis has been
demonstrated in a 21-day
experimental gingivitis study.
ZCT/Triclosan reduced the
development of gingival bleeding
sites by significantly more than ZCT
alone, suggesting that the system
has the potential to give a gingival
health benefit in a six-month
unsupervised brushing study. Zinc
and Triclosan employ multiple
modes of antimicrobial action and
these result in reduced growth,
inhibition of glucose uptake and
metabolism and modified virulence
of periodontal pathogens.
Importantly, the effects of zinc and
Triclosan are additive and
complementary. Oral substantivity
is a pre-requisite of any agent for
anti-plaque activity in vivo.
Pharmacokinetic data demonstrate
that 30% of the zinc and Triclosan
dosed is retained immediately after
brushing. Saliva decay curves
indicate that Triclosan is cleared
more quickly from the mouth than
zinc, consistent with the
physicochemical properties of these
agents. Triclosan is present in
plaque for at least 8h and in the
oral mucosa for at least 3h after
brushing.
Antibacterial dentifrices: clinical data and relevance with emphasis on zinc/Triclosan
Gjermo P* and Saxton CA (*Department of Periodontology, University Dental School, Oslo, Norway)
J Clin Periodontol 1991, 18,
468-473
The present review concerns the
effect on plaque and gingivitis of
some antibacterial dentifrices. The
difficulties of including cationic
agents in conventional dentifrice
formulations are briefly discussed.
The focus is on two recently
introduced dentifrices with
Triclosan as the active ingredient.
One aims at providing a slow
release reservoir of Triclosan in the
oral cavity by delivering the
substance dissolved in a lipophilic
copolymer. Three-month results
indicate a modestly improved effect
on plaque and gingivitis compared
to that of Triclosan alone. Longterm
studies are needed before
conclusions on the clinical
relevance can be drawn. The other
dentifrice on the market utilises the
principle of additive effects by
combining Triclosan and zinc citrate
in the formulation. The
combination appears to be more
effective against plaque and
gingivitis than either compound
alone. Studies of up to one year
duration indicate that the level of
oral hygiene and gingival health
obtained through an initial period
of motivation and oral hygiene
instruction can be maintained by
regular use of the test dentifrice,
while most subjects in the control
group returned to
pre-experimental levels.
Microbiological monitoring
indicates no major shifts in plaque
ecology nor any development of
resistant bacteria, and adverse sideeffects
have not been observed. It
is concluded that the new
approaches to chemical plaque
control may be beneficial to the
population at large, and thus of
great clinical relevance.
Oral Pharmacokinetics of copper (II) ions delivered by mouthwashes and toothpastes
Creeth JE and Simons J
J Dent Res 1992, 71, 558
Interleukin-6 (IL-6) in crevicular fluid (CF) from adult periodontitis (AP) patients
Wilton JMA*, Austin AK, Rogers PA, Johnson NW* and Powell JR (*Medical Research Council, Dental Research Unit, London, UK)
J Dent Res 1992, 71, 698
Comparison of two Triclosan dentifrices on developing gingivitis
Saxton CA and Cummins D
J Dent Res 1992, 71, 558
Mediators of inflammation and tissue destructive metabolism in gingival fluid
Powell JR
J Dent Res 1992, 71, 747
Affect of therapy upon levels of crevicular fluid inflammatory analytes
Powell JR, Caves J and Smales F* (*The London Hospital Medical College, London, UK)
J Dent Res 1992, 71, 622
Longitudinal study of crevicular fluid in a healthy population
Caves J, Powell JR, Alexander DC* (*Naval Dental School, Bethesda, USA)
J Dent Res 1992, 71, 553
Bacteria as a source of alkaline phosphotase in GCF
Harrop GJ and Penet SA
J Dent Res 1992, 71, 554
Sulphated GAG and GCF from periodontitis patients and healthy subjects
Long SP and Harrap GJ
J Dent Res 1992, 71, 552
Delivery of antiplaque agents from dentifrices, gels and mouthwashes
Cummins D and Creeth JE
Int Dent J 1992, 71, 1439-1449
Antiplaque agents delivered from
toothpastes, gels, or mouthrinses
can augment mechanical oral
hygiene procedures to control the
formation of supragingival plaque
and the development of early
periodontal disease. Clinically
effective antiplaque agents are
characterized by a combination of
intrinsic antibacterial activity and
good oral retention properties. The
overall oral retention of an
antiplaque agent is determined by
the strength and rate of association
of the agent with its receptor sites
and the accessibility of these sites.
The substantivity of an antiplaque
agent and its clearance from the
oral cavity are determined by the
rate of dissociation of the agent
from the receptor sites and the
salivary composition and flow rate.
Positively charged and non-charged
organic molecules, metal ions,
enzymes, and surface-active agents
have all been considered as
antiplaque agents. To exert clinical
antiplaque activity, an antimicrobial
agent must be formulated in a
chemically compatible delivery
vehicle to give optimal release and
uptake to the sites of action in a
biologically active form during its
time of application. In principle,
antiplaque activity may be
enhanced by combining
antimicrobial agents with broadly
similar, but complementary, modes
of action. Alternatively, the activity
of a single agent may be increased
by use of a retention aid to
enhance oral substantivity.
Substantial evidence exists to
demonstrate the validity of the first
approach. However, there are a
few data, as yet, to support the
effectiveness of the second. The
oral mucosa is the bulk retention
site for all clinically proven
antiplaque agents. Plaque, the
pellicle-coated tooth surface, and
saliva are probably all sites of
biological action. A detailed
understanding of the interactions
between agents and the various
receptor sites, and of the
importance of these receptor sites
to biological activity, is generally
lacking.
Elevated levels of the lgG2 subclass in serum from patients with a history of destructive periodontal disease
Wilton JMA*, Hurst TJ*, Stern JAC*, Caves J, Tilley C* and Powell JR (*Medical Research Council, Dental Research Unit, London, UK)
J Clin Perio 1992, 19, 318-321
The levels of the four subclasses of
IgG were estimated in the serum
from 35 patients with a history of
chronic periodontitis and 35
matched controls. The levels of IgG2
were significantly (p<0.019) elevated
in the patients (3.756g 1-1)
compared to the controls (2.882g 1-
1). The data suggests that the
predominant antibody response to
periodontal pathogens in
periodontitis may be directed against
carbohydrate or glycolipid antigens.
Interleukin-1Beta (1L-1B) levels in gingival fluid from adults with previous evidence of destructive periodontitis
Wilton JMA*, Bampton JLM*, Griffiths GS*, Curtis MA*, Life JS*, Johnson NW*, Powell J, Harrap GJ and Critchley P (*Medical Research Council, Dental Research Unit, London, UK)
J Clin Perio 1992, 19, 47-53
We have estimated the levels of
Interleukin-1 beta (IL-1ß) by ELISA
in gingival crevicular fluid (GCF) at
58 sites from 37 patients with
adult periodontitis. GCF was
collected for 5s on filter papers and
a second sample was collected for
30s one minute later. 68/116 strips
yielded detectable levels of IL-1ß.
IL-1ß was present in both the first
and second samples at 28 sites, in
the first only at four sites and in
the second only at eight sites; 18
sites were below the level of
detection for the assay. When the
concentrations of IL-1ß were
calculated in the original volume of
GCF on each strip, the mean value
for positive strips was 34.16 ±
29.45 (SD)pg/µl with a range from
1.75 to 97.13ºpg/µl. There were no
statistically significant correlations
with a plaque index, bleeding index
or probeable crevice depth (pocket
depth). The results indicate that IL-
1 is present in the GCF from a
proportion of sites with evidence of
previous periodontal destruction.
Reduced development of gingivitis by mouthrinses containing zinc and Triclosan
Schaeken MJM*, van der Hoeven JS*, Saxton CA and Cummins D (*Department of periodontics, University of Nijmegen Dental School, Nijmegen, The Netherlands)
J Dent Res 1993, 72, 374
IMAGEM 12
Improved gingival health and reduced calculus by zinc/Triclosan mouthrinses
Schaeken M*, Saxton CA and van der Hoeven H* (*Department of periodontics, University of Nijmegen Dental School, Nijmegen, The Netherlands
J Dent Res 1993, 72, 374
Longitudinal study of crevicular fluid IgG subclass in adult periodontitis
Powell JR, Caves J, WIlton JMA* and Johnson NW* (*Medical Research Council, Dental Research Unit, London, UK)
J Dent Res 1993, 72, 268
A combination of therapeutic agents for the control of dental plaque and gingivitis in man
Saxton CA
Thesis 1993, Catholic University of
Nijmegen, Nijmegen, The
Netherlands, Unilever Research,
Wirral, UK
This dissertation is based on the
premise that improved control of
bacterial plaque deposits on teeth
in humans is both necessary to
maintain oral health and, to the
individual, socially desirable. Several
investigations have shown that
mechanical means, in practice, are
insufficient to suppress bacterial
plaque formation effectively. The
research presented in this
dissertation was therefore aimed at
investigating the efficacy of
chemical antiplaque agents to act
against bacterial overgrowth to the
extent that gingival health can be
achieved and sustained. Although
not specifically included in the
investigation, it is assumed that
maintenance of low levels of
gingivitis will reduce the potential
of the local site specific
environment to cause periodontal
breakdown as demonstrated in
studies by Lindhe and Nyman
(1975), Axelsson and Lindhe (1978).
The epidemiology of periodontal
disease related factors, particularly
that of dental plaque is briefly
reviewed together with the use of
mechanical methods of plaque
removal and efficacy of dentifrices
containing chemical agents aimed
at improving plaque control.
Oral delivery and clearance of antiplaque agents from Triclosan-containing dentifrices
Creeth JE, Abraham P, Barlow JA and Cummins D
Int Dent J 1993, 43, 387-397
Oral delivery and clearance of
Triclosan and zinc were studied
following use of three commercially
available Triclosan-containing
toothpastes. One paste contained
0.3% Triclosan and 2% PVM-MA
copolymer, one contained 0.3%
Triclosan and 5% sodium
pyrophosphate and the third
contained 0.3% Triclosan and
0.75% zinc citrate trihydrate. Each
gave similar total oral retention of
Triclosan (37%-46% of the dose).
However, clinically important
product differences were observed
in the salivary clearance of Triclosan
and in Triclosan delivery to plaque.
The Triclosan/zinc paste delivered
more Triclosan to oral reservoirs (as
measured by the area under the
salivary clearance curve) than either
the Triclosan/PVM-MA or the
Triclosan/pyrophosphate paste
(p<0.001). The Triclosan/zinc paste
produced higher Triclosan levels in
plaque than the Triclosan/PVM-MA
paste (109 µg/g versus 78µg/g,
p<0.05). Zinc was effectively
delivered to oral surfaces by the
Triclosan/zinc paste, and was
cleared more slowly than Triclosan
(single-reservoir t1/2 = 50min).
After use of the Triclosan/zinc paste
the zinc level in plaque was
153µg/g, a seven-fold increase over
the control. These results
demonstrate that good delivery of
Triclosan requires a highly
optimised formulation.
Furthermore, they suggest that the
superior clinical effects of the
Triclosan/zinc paste are due to a
combination of superior delivery of
Triclosan to oral sites of action
together with effective delivery of a
second, complementary antiplaque
agent, zinc.
The effects of a silica-based dentifrice containing Triclosan and zinc citrate on supragingival plaque and calculus formation and the control of gingivitis
Svatun B*, Saxton CA, Huntington E and Cummins D (*Department of Pedodontics, University Dental School, Oslo, Norway)
Int Dent J 1993, 43, 431-439
A double blind, seven-month
parallel clinical study was
conducted to determine the effect
of a dentifrice containing 0.3%
Triclosan and 0.75% zinc citrate in
a 0.8% sodium
monofluorophosphate/silica base
on supragingival plaque, gingivitis
and supra-gingival calculus
formation, compared to a 0.8%
onofluorophosphate/silica control
dentifrice. The results of this clinical
study demonstrate that the use of
the Triclosan/zinc citrate dentifrice
over a seven-month period
provided a statistically significant
and clinically relevent benefit in
controlling gingivitis, compared to
a control dentifrice. Supragingival
plaque and calculus levels were
also significantly reduced in
comparison to the effects of a
control dentifrice.
The effect of dentifrices containing Triclosan on the development of gingivitis in a 21-day experimental gingivitis study
Saxton CA, Huntington E and Cummins D
Int Dent J 1993, 43, 423-429
The aim of this study was to
investigate the ability of Triclosan
dentifrices to delay the
development of gingivitis during a
21-day period without
toothbrushing. Test pastes
contained 0.3% Triclosan; seven
also contained 0.75% zinc citrate;
one other contained 2% Gantrez®.
Plaque and gingivitis increased
significantly (p<0.001) between day
0 and day 21 in the control group.
There was no evidence to reject the
assumption of similar efficacy
across the seven Triclosan/zinc
citrate variants. For the combined
Triclosan/zinc citrate groups,
statistically significant reductions in
plaque formation and in gingivitis
relative to the control were
recorded. Reductions in plaque and
gingival bleeding compared to
control for the Triclosan/Gantrez®
group were not statistically
significant, although reductions in
gingival indices were. The greater
reduction in the Gingival Index of
the Triclosan/zinc group was also
statistically significantly different
from that of the Triclosan/Gantrez®
group, suggesting that a dentifrice
containing the former would have
a greater antigingivitis potential
than a dentifrice containing the
latter.
The effect of chlorhexidine and zinc-Triclosan mouthrinses on the production of acids in dental plaque
van der Hoeven JS*, Cummins D, Schaeken MJM* and van der Ouderaa FJG (*Department of Periodontics, University of Nijmegen Dental School, Nijmegen, The Netherlands
Caries Res 1993, 27, 298-302
Chlorhexidine and zinc in
combination with Triclosan, are
used as anti-plaque agents in the
prevention of gingivitis. The
multifunctional activity of these
compounds against bacterial cells
has been proposed to include
interference with sugar transport
and reduction of glycolysis. In this
study the ability of the agents to
reduce acid production in dental
plaque in vivo has been
investigated. Samples of smoothsurface
plaque were collected from
individuals who had been rinsing
for several weeks with (a)
chlorhexidine (0.12%, Peridex®); a
combination of zinc and Triclosan
in mouthwashes containing (b)
high and (c) low concentrations of
humectant; or (d) a control
mouthwash. Analyses using
isotachophoresis showed that
resting plaques in the chlorhexidine
and zinc/Triclosan groups contained
less acetate than the control group.
Acids were also measured 15
minutes after a glucose rinse.
Compared with the control, the
amount of lactate was significantly
decreased (45%) in the
chlorhexidine group, while lactate
reduction (20%) in the
zinc/Triclosan (high humectant)
group was not statistically
significant.
Interleukin-1B and 1gG subclass concentrations in gingival crevicular fluid from patients with adult periodontitis
Wilton JMA*, Bampton JLM*, Hurst TJ, Caves J and Powell J (*Medical Research Council, Dental Research Unit, London, UK)
Arch Oral Biol 1993, 38, 55-60
Interleukin-1ß (IL-1ß) and the four
IgG subclasses were measured in
gingival crevicular fluid (GCF) at 35
sites in 19 patients with adult
periodontitis. Serum concentrations
of the IgG subclasses were assayed
in 16 patients. IL-1ß was detected
GCF at 88.6% of sites at
concentrations ranging from 12.38-
420.90pg/µl (mean 138.35 ±
112.61pg/µl). IgG1 was detected at
81.2% sites, IgG2 at 93.6%, IgG3
at 71% and IgG4 at 71%. Absolute
concentrations in GCF were: IgG1 –
2.419g/l ± (SD) 3.389: IgG2 – 2.945
± 6.434; IgG3 – 0.118 ± 0.144;
IgG4 – 0.864 ± 1.336. There were
no significant correlations between
IL-1ß concentrations, GCF volume
or the clinical status of the sample
site. IL-1ß was not correlated with
any of the IgG subclasses. The
absolute concentrations of all
subclasses in GCF were significantly
negatively correlated with GCF
volume and positively correlated
with the Bleeding Index. Only IgG4
was significantly negatively
correlated with a probeable crevice depth index. The concentration of
each IgG subclass was positively
correlated with the other three IgG
subclasses. Subclass concentrations
in GCF, relative to serum
concentrations, were not correlated
with GCF volume or clinical status.
Relative concentrations of IgG1,
IgG2 and IgG3 showed significant
positive correlation with each
absolute concentration of the other
subclasses but IgG4 did not show
this relation. It was concluded that
IL-1ß is not related to clinical
measurements of inflammation of
previous attachment loss. The data
suggest that IgG in GCF is largely
derived from plasma but that some
IgG4 may be locally synthesized.
IMAGEM 13
The effects of three silica dentifrices containing Triclosan on supragingival plaque and calculus formation and on gingivitis
Svatun B*, Saxton CA, Huntington E and Cummins D (*Department of Pedontics, Oslo University Dental School, Oslo, Norway)
Int Dent J 1993, 43, 441-452
A double blind, seven month clinical
study was conducted to determine
the effects of three Triclosan
containing test dentifrices on
supragingival plaque, gingivitis and
supragingival calculus formation
compared to a 0.8%
monofluorophosphate-silica control
dentifrice. Each test dentifrice
contained 0.3% Triclosan;
additionally one contained 0.75%
zinc citrate, the second contained
2% Gantrez® and the third
contained 5% pyrophosphate.
Subjects were assigned to one of
the three test groups or to the
control group according to random
allocation within nine strata.
Subjects were evaluated for
supragingival plaque and calculus
formation and for gingivitis after
one, four and seven months use of
the dentifrices. After seven months,
the Triclosan/Gantrez® and the
Triclosan/pyrophosphate dentifrices
each provided a statistically
significant reduction of
approximately 25% in gingival
bleeding compared to the control.
Neither dentifrice gave statistically
significant reductions in
supragingival plaque or calculus
formation. In contrast, the
Triclosan/zinc citrate dentifrice
provided statistically significant
reductions of 33% in supragingival
plaque, 51% in gingival bleeding
and 67% in supragingival calculus
formation. The reductions in gingival
bleeding and calculus formation
were statistically superior to those of
the Triclosan/Gantrez® and the
Triclosan/pyrophosphate products.
The results demonstrate that use of
the Triclosan/zinc citrate dentifrice
over a seven month period provided
statistically significant and clinically
relevant reductions in supragingival
plaque and calculus formation, and
control of gingivitis as compared to
a control dentifrice.
Interrelationship of crevicular fluid inflammation associated markers in periodontitis
Powell JR, Caves J, Austin AK and Wilton JMA* (*Medical Research Council, Dental Research Unit, London, UK)
J Dent Res 1994, 73, 393
Effect of therapy upon levels of crevicular fluid inflammatory analytes
Alexander DC*, Martin J, Caves J and Powell JR (*Naval Dental Research Inst, Bethesda, USA)
J Dent Res 1994, 73, 163
Effect of pre-experimental maintenance care duration, on the development of gingivitis in a partial mouth experimental gingivitis model
van der Weijden GA*, Timmerman MF*, Danser MM*, Nijboer A*, Saxton CA and van der Velden U* (*Department of Periodontology, ACTA, Academic Centre for Dentistry, Amsterdam, The Netherlands
J Periodontal 1994, 29, 168-173
The present study was designed to
evaluate if different periods of
supervised oral hygiene prior to the
experimental gingivitis trial have an
effect on the amount of
inflammation which develops in the
‘toothshield’ model. Two groups
were compared. One group (Group
A) was supervised over a five-month
period before experimental
gingivitis. Six months later Group A
participated in a second trial, this
time receiving only a one-month
pre-trial. A second group (Group B)
which served as a control was
supervised over a pre-trial period of
one-month prior to the start of the
experimental gingivitis phase.
During the pre-trial period all
subjects undertook a regime of
vigorous oral hygiene which
included polishing of the test
quadrant in the upper jaw and
supervised subgingival brushing,
interdental taping or the use of
toothpicks. The presence of plaque
and bleeding were assessed.
Following the pre-trial period all
plaque control measures in the
experimental area were prevented
during oral hygiene periods by the
temporary placement of soft, loosely
fitting vinyl toothshield guards.
During this period they accumulated
plaque rapidly and developed a
generalized gingivitis. The results of
this study indicate that, irrespective
of the length of the pre-trial period,
subjects by group develop a
comparable mean level of plaque
and gingival bleeding. However, the
extent to which gingivitis develops
differs among individuals and was
for a number of subjects not
consistent. Therefore, in designing
an experimental gingivitis trial care
should be taken to include a
sufficient number of subjects to
account for individual variation.
Interrelationship of inflammation associated markers in periodontitis
Powell JR, Caves J, Wride HJ, Austin A and Wilton JMA (MRC Dental Research Unit, London, UK)
Inflammation Res 1995, 44, 281
Evaluation of a zinc citrate/dual -phase dentifrice in a human calculus model
Putt MS*, Milleman JL*, Kleber CJ*, Truelove RB, and Williams DR (*Indiana-Purdue University, Fort Wayne, USA)
J Dent Res 1995, 74, 209
Clinical evaluation of an anti-tartar dentifrice containing hydrogen peroxide
Marks RG*, Hefti AF*, Conti AJ*, Magnusson NI*, Taylor M*, and D. Willliams (*University of Florida, USA)
J Dent Res 1995, 74, 25
Comparison of tartar control dentifrices using a 2-Week human calculus model
Putt MS*, Milleman JL*, Kleber CJ*, Truelove RB, and Williams DR (*Indiana-Purdue University, Fort Wayne, USA)
J Dent Res 1995, 74, 209
Evaluation of anti-tartar dentifrices on calculus formation
Taylor M, Marks RG*, Hefti AF*, Conti AJ *and Willliams D (*University of Florida, USA)
J Dent Res 1995, 74, 50
Effect of baking soda-peroxide dentifrice on Postsurgical wound-healing
Dentino AR*, Ciancio SG*, Bessinger M*, Mather M*, Cancro L and Fischman S**
Am J Dent 1995, 8, 125-127
Purpose: To investigate the effect of a
baking soda-hydrogen peroxide
(0.75°/0) dentifrice on wound
healing, plaque formation, gingival
inflammation, patient comfort,
probing depth, and clinical
attachment level following gingival
flap surgery. Materials and Methods: A randomized, double-blind
crossover study involving 25
patients requiring bilateral maxillary
gingival flap surgery was
completed. The effects of twice
daily brushing with a baking
soda-hydrogen peroxide dentifrice
(Mentadent) or a placebo dentifrice
(Crest) were observed over a 28-
day post-surgical period. Gingival
index (GI), plaque index (PI),
probing depth (PD), clinical
attachment level (GAL) and
gingival bleeding index (BI) were
recorded pre-surgically and at day
28 for each surgical sextant. At
days 7 and 14, soft tissue
appearance/wound healing (STA)
was assessed based on color and
edema, PI’s were determined and
patient comfort was ascertained by
report. Results: Post-surgical wound healing was
statistically significantly improved at
day 7 with the trend continuing to
day 14 when Mentadent dentifrice
was used as compared to Crest
dentifrice. However, there was no
statistical difference in the PI values
between the test and control
dentifrice throughout the study.
Use of Mentadent may be an
effective aid in the early phase of
healing following gingival flap
surgery.
Risk factors associated with progression of periodontitis
Machtei EE*, Dunford R**, Housmann E**, Grossi SG**, Powell JR, Offenbacher S***, Cummins D, Zambon J** and Genco RJ** (*Rambam University Hospital, Oral Biology & Perio Unit, Haifa, Israel, **SUNY, Buffalo, New York, USA, ***University of North Carolina, Chapel Hill, USA)
J Dent Res 1996, 75: 48
Interleukin l-B, prostaglandin E2 and IgG subclasses in gingival crevicular fluid of patients undergoing periodontal therapy
Alexander DCC, Martin JC, King PJ, Powell JR, Caves J and Cohen ME J
Periodontol 1996, 67, 755-762
Determination of the presence of
inflammatory products found in
gingival crevicular fluid (GCF) may
be of value in evaluating both
periodontal disease status and the
outcome of therapy.
Immunoglobulin G subclasses 1
through 4 (IgGs), interleukin 1-ß
(IL-1ß), and prostaglandin E2 (PGE2)
have all been shown to be present
in GCF. This study monitored IgGs,
IL-1ß, and PGE2 in GCF of 18 adult
patients. They progressed through
periodontal treatment toward
maintenance therapy. Sites were
selected from the most severely
affected sextant as determined by
probeable crevice depth (PD) at
initial examination (IE). GCF was
collected on four occasions: initial
examination; 4 weeks after
completion of initial therapy (oral
hygiene counseling, and scaling
and root planing); 3 months after
completion of surgery; and 7 to 9
months later at a maintenance visit.
All variables were reduced to binary
form (positive or negative), and
break points chosen to separate
the approximately symmetrical bellshaped
areas (negatives) from the
skewed tails (positives). Repeated Clinical examination measures analyses of variance were
performed to detect significant
changes in all variables across time.
Significant improvements were
observed for all the clinical
variables measured: PD attachment
level, and bleeding on probing.
However, significant reductions for
the GCF components only occurred
in the concentrations of IL-1ß and
PGE2 but were not evident until the
maintenance sampling. Surprisingly,
GCF:serum ratios of Ig subclasses
did not change significantly over
the course of the investigation. The
robustness of the levels of these
components may be due to
inflammation associated with the
healing process, or to a further
plaque induced response.
IMAGEM 15
Longitudinal study of prognostic factors in established periodontitis patients
Machtei EE*, Dunford R**, Housmann E**, Grossi SG**, Powell JR, Offenbacher S***, Cummins D, Zambon J** and Genco RJ** (*Rambam University Hospital, Oral Biology & Perio Unit, Haifa, Israel, **SUNY, Buffalo, New York, USA, ***University of North Carolina, Chapel Hill, USA)
J Clin Periodontol 1997, 24,
102-109
Numerous indicators for disease
progression have been described in
the last decade. The purpose of
this study was to examine,
longitudinally, a large battery of
clinical, microbiological, and
immunological indicators, to try to
determine whether the presence of
one or a combination of these
parameters at baseline, would
correlate positively with increased
attachment and or bone loss (true
prognostic factors). Following initial
screening, 79 patients with
established periodontitis were
monitored longitudinally for one
year. Whole mouth clinical
measurements, plaque gingival
and calculus indices, together with
pocket depth and attachment level
measurements, were repeated
every three months. Full mouth
radiographic survey, performed at
baseline and 12 months, served to
determine changes in crestal bone
height using an image
enhancement technique.
Subgingival plaque samples were
taken at baseline and every 3
months. Immunofluorescence
assays were performed for the a
battery of target microorganisms.
Serum and GCF samples for IgG
subclasses analysis were obtained
at each visit and assayed using
ELISA techniques. Likewise blood,
samples were also drawn at each
visit for a quantitative analysis of
serum cotinine level. The overall
mean attachment loss (AL) and
bone loss (BL) were almost identical
(0.159mm and 0.164mm,
respectively). Individual patients
variation was large ( -0.733 to +
1.004 mm). An overall 6.89°/u of
sites were active; individual
patients’ means ranged from
0-28.9%. Mean pocket depth (PD)
showed minimal change over the
study period (-0.033 mm) thus
suggesting that most if not all the
AL was accompanied by
concomitant gingival recession.
Smokers exhibited greater AL and
radiographic BL compared to nonsmokers.
Likewise, patients’
nicotine level showed direct
correlation with outcomes of progressive periodontal breakdown.
Past severity of periodontal
involvement, as reflected in the
patients baseline PD, AL and crestal
bone height, showed good
correlation with longitudinal
changes in the periodontium. This
correlation was higher for crestal
BL as the outcome variable, while
somewhat smaller for change in AL
as the outcome variable. Bacteroides forsythus (Bf.), Prevotella intermedia (Pi.) and Porphyromonas gingivalis (Pg.)
were frequently found in these
patients. The presence of these
microorganisms at baseline was
associated with further disease
progression. Subjects with mean
baseline pocket depth equal or
greater than 3.2mm were at
greater risk for future bone loss
1 year later
(O.R.2.97;C.I.1.02-8.70). Smokers
were at significantly greater risk for
further attachment loss when
compared to non-smokers
(O.R.5.41;C.1.1.50-19.5). Subjects
that harbored B. forsythus at baseline, were at
seven times greater risk for
increased pocket depth
(O.R.7.84;C.I.1.74-35.3). In
conclusion, past periodontal
destruction, smoking habits, Bf., Pg. and Pi. are prognostic factors
for further periodontal breakdown.
When designing clinical trials, or
when evaluating epidemiological
data, it is most important to
balance for these factors. Also,
treatment strategies should
attempt to eliminate or modify
these factors.
The effect of low cost chalk based dentifrices containing neem extract, on plaque and gingivitis, amongst users of natural products.
G. Subraya Bhat G, Arun Kumar M.S , Mahalinga Bhat K , Bhat KS, Vaidehi Ketkar, Bhattacharya SK and Bijlani NS
J. Indian Dent. Assoc., October
Issue 1998
Three month clinical studies were
conducted on a population of
natural product users, to determine
the effect of brushing with two
low cost chalk based toothpastes
containing neem extract, on plaque
and gingivitis. The fluoridated and
non-fluoridated toothpastes were
tested in two phases. In the first
phase, the experimental toothpaste
contained 1000ppm fluoride as
SMFP and in the second phase the
same formulation without Fluoride
was used. A control or no
treatment population who used
non-conventional dentifrices like
mango and cashew leaf, charcoal
and ash as a routine method of
oral hygiene, was used in both the
phases of the study. The control
population continued with their
routine habit throughout the study.
Subjects underwent a baseline
assessment for plaque and
gingivitis and were assigned to
either the experimental group
which received the test toothpaste
and a soft toothbrush and
instructions on brushing technique,
or the control group. At the end of
three months, there was a
significant reduction in plaque and
gingivitis for subjects using the
both the experimental toothpastes
without fluoride and with
1000ppm fluoride as SMFP, as
compared to the baseline as well
as control group. All reductions
were statistically significant at the
95% or greater level of confidence.
Effect of zinc citrate-triclosan dentifrices on plaque growth
Creeth JE, Lloyd AM, Schæfer F and Shearer BH
J Dent Res 78: 356-356 (Abstr
2001) Sp Iss 1999
Anti-calculus activity of a toothpaste with microgranules
O’Mullane DM*, Chesters RK, Finnerty A*, Huntington E and Jones PR (*Oral Health Services Research Centre, Cork, Ireland)
J Dent Res 77: 2123, Sp Iss B 1998
Clinical and metrology assessment of experimentally induced gingivitis
Yeganeh S*, Lynch E*, Shearer B, Heath MR*, Jovanovski V* and Zou L* (*St Bartholomew’s & the Royal
London School of Medicine &
Dentistry)
J Dent Res 78: 1965, p351, 1999
A method to measure interproximal delivery of fluoride and triclosan
Waterfield PC, Lester HE, Anklam JLR, Davies RH
J Dent Res 77: 498 (special issue B)
1998
Effect of zinc citrate-triclosan dentifrices on plaque growth
Creeth JE, Lloyd AM, Schäfer F,
Shearer BH
J Dent Res 78: 356-356 (Abstr
2001) Sp Iss, 1999
Comparison of mouthrinses and flossing on residual plaque after toothbrushing
Davidson KR*, Putt MS*, Kleber CJ*, Truelove R and Williams D (*Indiana-Purdue University, Fort
Wayne, Indiana)
J Dent Res 78 (special issue):249,
1999.
Effect of mouthrinses on residual plaque following toothbrushing and flossing
Milleman JL*, Putt MS*, Davidson KR*, Truelove R and Williams D (*Indiana-Purdue University, Fort
Wayne, Indiana)
J Dent Res 78 (special issue):249,
1999
Metrology: A Novel Method to Measure Plaque Removal by Dentifrices
Waterfield PC, Shearer B, Lynch E*,
Jovanovski V* and Morris-Clapp C*
(*St Bartholomew’s & the Royal
London School of Medicine &
Dentistry)
J Dent Res 78 (special issue), 498,
Abstr 3137, 1999
Plaque removal of mouthwashes and flossing following toothbrushing
Ciancio SG*, Truelove RB, Garvin CL and Williams DR
J Dent Res 78 (special issue):356,
1999.
(*SUNY at Buffalo, Buffalo, New
York)
Comparative plaque removal of mouthwashes following toothbrushing and flossing
Truelove RB, Ciancio SG*, Williams DR, Mather MA* and Garvin CL
J Dent Res 78 (special issue):356,
1999
(*SUNY at Buffalo, Buffalo, New
York)
IMAGEM 17
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