Oral Malodour

Reduction in the levels of oral malodour precursors by hydrogen peroxide: in vitro and in vivo assessments
Grigor J and Roberts AJ
J Clin Dent 1992, 3, 111-115

The potential of hydrogen peroxide to reduce the levels of salivary thiol precursors of oral malodor was investigated in vitro and in vivo. In both cases the concentration of thiol groups was determined colorimetrically by quantitative reaction with 4,4’-bis (dimethylamino) diphenyl carbinol. Addition of volumes of hydrogen peroxide solution (containing between 0.18 and 0.90mmol) to premeasured aliquots of saliva in vitro, resulted in reductions in salivary thiol levels of between 53% and 75% compared to controls. This positive indication prompted an in vivo investigation. The efficacy of a fluoridecontaining test toothpaste also containing 0.67% hydrogen peroxide and 5.48% sodium bicarbonate was evaluated in a crossover study using ten male and female subjects (non-smokers). All subjects used the test product and a control fluoride dentifrice, in a random order. For the duration of the study subjects used a standard silica-based toothpaste containing 1500 ppm F (as sodium monofluorophosphate) exclusively for their normal oral hygiene. On each sampling morning they refrained from oral hygiene and eating and drinking on rising. At the test facility they generated a background saliva sample stimulated by chewing unflavored, unsweetened gum. Subjects brushed for one minute with 1.50 (±0.05)g test or control paste and generated another saliva sample as before, 30 minutes after product application. Using the same analytical procedures the mean (±SEM)% reduction in salivary thiol levels post treatment compared to baseline was found to be 59.0 (±7.0)% for the test product compared with 12.5 (±5.2)% for the fluoride control paste. Analysis of covariance showed that the test paste containing hydrogen peroxide/sodium bicarbonate was significantly superior (p<0.001) to the fluoride control, at reducing the concentration of oral malodour.

Reduction of oral malodour by zinc-citrate containing dentifrices
Grigor J, Roberts AJ and Tonzetitch J* (*University of British Columbia, Canada)
J Dent Res 1992, 272

Reduction of oral malodour and its thiol precursors by mouthrinses containing soluble zinc complexes
Grigor J, Huntington E, Roberts AJ and Tonzetitch J* (*University of British Columbia, Canada)
J Dent Res 1993, 72, 272

Evaluation of analysis of salivary thiol levels as prediction of oral malodour
Grigor J, Huntington E, Roberts AJ and Tonzetitch J* (*University of British Columbia, Canada)
J Dent Res 1993, 72, 272

Oral malodour reduction by dentifrice containing stannous and zinc ions
Grigor J, Huntington E, Matheson JR, Raven SJ and Tonzetitch J* (*Department of Oral Biology, University of British Columbia, Canada)
J Dent Res 1994, 73, 165

The efficacy of a combined zinc and Triclosan system in the prevention of oral malodour
Raven SJ, Matheson JR, Huntington E and Tonzetitch J* (*University of British Columbia, Vancouver, Canada)
in: “Bad Breath, A Multidisciplinary Approach”, Leuven University Press 1996

The incidence of oral malodour in the general population is high. with many people experiencing problems such as “morning mouth”. Mass marketed dentifrice and mouthwash can play an important role in helping to reduce both the incidence and the extent of oral malodour. In this paper the requirements of a mass market product are discussed and data presented to demonstrate the efficacy of products containing the combination of zinc and Triclosan. The efficacy is demonstrated using a variety of evaluation techniques and the importance of product form and frequency of use are discussed. For a product to be effective and suitable for mass marketing it must satisfy a number of criteria. It should obviously be safe for unsupervised use, have acceptable sensory properties to encourage regular use and be convenient as well as cost effective. In addition, it should contain an active species such as an anti-microbial agent, a compound capable of complexing volatile odour components, or an odour masking ingredient. The presence of an active species does not necessarily guarantee clinical efficacy and thus product efficacy should also be demonstrated in a clinical study against a suitable control.

Oral malodour reduction by dentifrice containing zinc citrate and Triclosan
Huntington E, Matheson JR, Raven SJ and Tonzetitch J* (*University of British Coumbia, Vancouver, Canada)
J Dent Res 1997, 74, 887

Correlation of halimeter with in vivo levels of VSC
Grigor J, Huntington E, Matheson JR, Raven SJ, Santos S and Tonzetitich J* (*University of British Columbia, Canada)
J Dent Res 1997 76, 885

Oral malodour reduction by mouthwash containing zinc sulphate and Triclosan
Huntington E, Matheson JR, Raven SJ and Tonzetitch J* (*University of British Columbia, Vancouver, Canada)
J Dent Res 1997, 74, 886

In vitro Technique for assessing substantivity and efficacy of antimalodour agents
Grigor J, Codipilly M*, Matheson JR, Pickles NA, and Kleinberg I* (*SUNY, Stoneybrook, USA)
J Dent Res 1997 76, 358

Negative correlation between oral malodour and numbers and activities of sulphate-reducing bacteria in the human mouth.
Willis CL*; Gibson GR*; Holt J and Allison C
(*Institute of Food Research, Earley Gate, Berks, UK) Archives of oral biol. (England) Aug 1999 , 44 (8) p665-70

The majority of cases of oral malodour are thought to be due to bacterial activities in the mouth, but many of the bacterial species responsible have not been identified. Volatile sulphide compounds have been proposed as constituents of oral malodour. Therefore, the relation between intensity of odour and numbers of bacteria in the mouth that are sulphide-producing from sulphate was investigated. Numbers of such dissimilatory sulphate-reducing bacteria (SRB) and sulphide reduction rates were evaluated. In samples from different oral sites in relation to measures of oral malodour. Results showed that sulphate-reducing bacterial numbers and activities were negatively correlated with malodour, as determined by organoleptic assessment and measurement with a sulphidemonitoring instrument, the Halimeter. The data indicate that sulphide produced by oral SRB may not be an important contributor to oral malodour. A rather poor correlation was observed between Halimetric and organoleptic values, indicating that these methods may measure different aspects of oral malodour intensity.

IMAGEM 1

Hypersensitive Teeth

The effectiveness of potassium salts as desensitising agents in the presence of SMFP
Chesters RK, Kaufman H*, Wolff M*, Huntington E and Kleinberg I* (*State University of New York at Stony Brook, New York)
J Dent Res 1990, 69, 164

Over-the-counter dentifrices in the treatment of tooth hypersensitivity – review of clinical studies
Kanapka JA
Dent Clin North Am 1990, 34, 545- 560

Dentinal hypersensitivity is a common condition. Most cases, after professional diagnosis, can be treated simply and inexpensively by home use of a desensitizing dentifrice. Because the habit of toothbrushing with a dentifrice for cosmetic reasons is well established in the population, compliance with this regimen is not a problem. Dentifrices incorporating potassium nitrate, strontium chloride, and dibasic sodium citrate have all been clinically determined to be effective desensitizers, and several brands have been critically evaluated and accepted by the Council on Dental Therapeutics of the ADA. During the years, clinical methodology has evolved from monadically designed, subjective investigator reports to present-day, double-blind, placebocontrolled clinical trials employing stimuli that are quantifiable in physical units. Future development of more effective desensitizing dentifrices will depend on standardization in clinical design, especially regarding stimulus choice and mode of application.

Do strontium salts block nerve conduction?
Stead WJ
J Dent Res 1993, 72, 727

The prevalence of self reported hypersensitive teeth
Murray LE and Roberts AJ
Archs Oral Biol 1994, 39, 129s

Mathematical model for potassium diffusion in dentinal tubules
Stead WJ, Warren PB*, Orchardson R* and Roberts AJ (*University of Glasgow Dental School, Glasgow, UK)
Archs Oral Biol 1994, 39, 145

Effects of potassium ions on action potential conduction in A- and C-Fibers of rat spinal nerves
Peacock JM and Orchardson R (Institute of Physiology, University of Glasgow, Scotland UK)
Dent Res 1995, 74(2), 634-641

Potassium ions in dentifrices for treating ‘hypersensitive’ dentin are believed to act directly on intradental nerves by raising extracellular potassium ion concentration ([K+]o) sufficiently to prevent action potential generation by axonal accommodation. However, the [K+]o necessary to block nerve conduction is not precisely known, nor is it certain that K+ can diffuse from a dentifrice in sufficient amounts to inactivate intradental nerves. To establish more accurately the [K+]o required to block nerve conduction under controlled conditions, we studied the effects of increased [K+]o on the sizes of compound action potentials (CAP) recorded from rat spinal nerves in vitro. [K+]o was increased by the addition of either KCI or KNO3 to Krebs’ solutions applied to the central portion of the nerves. CAP attenuation increased in a dose-dependent manner as [K+]o was raised in the 8 to 64mmol/L range, and complete block was generally produced with solutions containing at least 32mmol/L K+. CAP attenuation was reversible, and recovery times increased with increasing [K+]o. The effects of KCI and KNO3 solutions were the same for all [K+]o tested. Half-maximal (50%) reduction in the Aß-fiber component of the CAP occurred with 17.4mmol/L K+, and with 17.8mmol/L and 19.3mmol/L K+, respectively, for the A∂- and C-fiber components. Control experiments with glucose and choline chloride confirmed that the conduction block observed with increased [K+]o was not due to increased solution osmolarity or ionic strength. Assuming that intradental axons are as sensitive to altered [K+]o as spinal nerve axons, we suggest that for K+ in dentifrices to block intradental nerve conduction: (1) [K+]o in excess of 8mmol/L would have to be achieved around nerve axons in the inner dentin or peripheral pulp, and (2) increases in [K+]o of these magnitudes would have to be maintained in order for intradental nerve inactivation to be sustained.

Reproducibility of new and conventional methods for assessing dentine sensitivity
Ide M, Ashley FP and Wilson RF (Guys Hospital Dental School, London)
J Dent Res 1995, 74, 861

A mathematical model of potassium ion diffusion in dentinal tubules
Stead WJ, Orchardson R* and Warren PB (*Institute of Biomedical and Life Sciences, West Medical Building, University of Glasgow, UK)
Archs oral Biol 1996 Vol 41, no 7 pp 679-687

Desensitizing agents containing potassium ions (K+) are believed to inactivate intradental nerves by raising extracellular [K+]. A mathematical model was used to investigate factors affecting [K+] in dentinal tubules. The most important factors affecting the steady-state tubular [K+] were the tubular fluid-flow velocity, salivary [K+] and the permeability to potassium (k) of the barrier between the tubule and the pulp. Tubular [K+] decreased with increasing outward flow velocity and increasing k, whereas the dimensions of the tubule and odontoblast process had little effect. Following a I min simulated application of 500mmol/1 K+ to the dentine surface, [K+1 at the inner end of the tubule increased above steady-state levels for 20-30min. The maximum [K+] attained at the inner end of the tubule was around 30mmol/1 for an impermeable barrier (k = 0) and flow velocity of 1.4µm/s, but lower maximum tubular [K+] were achieved when either the outward flow velocity or k was increased. The model suggests that applying potassium-containing preparations to dentine may increase [K+] at the inner ends of dentinal tubules to levels sufficient to inactivate intradental nerves. However, the localized increase in [K+] is transient, and the concentration change will be lessened by conditions that increase the tubular fluid-flow velocity or the permeability of the barrier between the tubule and pulp.

IMAGEM 2

Specialised Research

Promoting dental health
Cowell CR and Sheiham A* (*London Hospital Medical College)
Published by King’s Fund, London 1981

Fluoride dentifrices
Ingram GS
Chapter in ‘Pediatric Dentistry’ CB Mosby Co 1982

Gel toothpastes: genesis
Pader M
Cosmet Toiletries 1983, 98, 71-76

The development of gel toothpastes from the formulation/technological principles to marketing the product is presented.

Photography and a study of the mottling of tooth enamel
Callender RM
J of Audiovisual Media and Medicine 1983, 6, 57-59

An intra oral photographic system was used to study mottling of tooth enamel in a clinical study of Danish schoolchildren. The methods used were reviewed.

Inlays, crowns and bridges. Fourth edition
Cowell CR, Curson I*, Kantorowicz CT** and Shovelton DS** (*University of London, King’s College) (**University Medical Hospital at Guy’s, London) (***University of Birmingham)
Edited by CT Kantorowicz Published by John Wright, Bristol, 1985

Surfactants in oral hygiene products
Pader M Surfactant
Sci Ser 1985 vol 16 (Surfactants Cosmet), 293-347

The role of surfactants in oral hygiene products is reviewed. Those surfactants used in oral hygiene products anionic, nonionic, cationic and surfactant interactions are discussed as well as the effects of surfactants on oral bacteria and oral tissues. Product formulations including dentifrices, tooth powders, mouthwashes and denture cleansers are also presented.

Combined study of coagulation kinetics and close-range aggregate structure
Lips A and Duckworth RM
J Chem Soc, Faraday Trans 1 1988, 84, 1223-1242

The kinetics of coagulation of model polystyrene latex spheres under both reaction and diffusion control have been studied. The zeroth moment of the aggregate distribution has been measured by an automated laser particlecounting method, and the second moment by time-resolved lowangle light scattering. The moments of the aggregate distribution can deviate from the predictions of the simple Smoluchowski constant-kernel equation. Acceleration in rate from reaction to diffusion control can occur in so-called rapid coagulation and in an intermediate regime of slow coagulation. In very slow coagulation, the rate decelerates, suggesting transition from reaction to equilibrium control. Interpretation on kinetic random polycondensation theory for an RAf process has yielded effective functionalities which increase with particle density and decrease with increasing reaction control. The observed deviations from constant-kernel Smoluchowski kinetics have important implications for the measurement of classical colloid stability plots and may be the origin of the discrepancies between the predictions of DLVO theory and kinetic measurements of colloid stability.

IMAGEM 3

Production of TGF-á and TGF-ß by cultured keratinocytes, skin and oral squamous cell carcinomas – potential autocrine regulation of normal and malignant epithelial cell proliferation
Partridge M*, Green MR, Langdon JD** and Feldmann M* (*Charing Cross Sunley Research Centre, Lurgan Avenue, London) (**Kings College Hospital, Denmark Hill, London)
Br J Cancer 1989, 60, 542-548

Transforming growth factors have a wide range of biological activities related to cell proliferation and differentiation. In general TGF-á promotes cell proliferation while TGF-ß may stimulate or inhibit proliferation depending on the cell type and growth factor environment. Cultured human keratinocytes, skin and oral squamous cell carcinomas were analysed for the presence of transcripts and protein for the transforming growth factors á & ß. Both growth factors were detected in cultured keratinocytes (which have receptors for and respond to both ligands), and in medium conditioned by these cells. Additionally transcripts for TGF-á were found preferentially in the basal, proliferative compartment of cultured keratinocytes. Similarly both growth factors were detected in oral squamous cell carcinomas and a highly significant inverse correlation was found between the levels of TGF-á and the epidermal growth factor receptor in these tumours. The data for TGF-á are consistent with the existence of an autocrine growth control loop influencing cell proliferation in both a normal cell type and malignant epithelial tissues, a process that in keratinocytes and responsive squamous cell carcinomas could be modulated by TGF-ß.

Studies on insoluble components in mature enamel follicle
Harrap GJ and Newsom BS
J Dent Res 1990, 69, 319

The prevalence and effectiveness of fissure sealants in Scottish adolescents
Chestnutt IG*, Schäfer F, Jacobson APM* and Stephen KW* (*University of Glasgow Dental School, Glasgow, UK)
Br Dent J 1992, 177, 125-129

The presence of fissure sealants was recorded in 4294 adolescents during a three-year, double-blind clinical caries trial, conducted in Lanarkshire, Scotland, between 1988 and 1992. Of 68, 704 occlusal surfaces examined at baseline, sealants were detected on 7011 (10.2%) surfaces, in 1596 subjects. Of these, 17.4% were judged as incompletely sealed. At the final examination 24.3% of sealants originally recorded as complete were missing, with partial loss observed on a further 18.2% of surfaces. At that time, 21.4% of surfaces unsealed but sound’ at baseline were recorded as decayed, filled or extracted due to caries, compared with 14.4% of surfaces on which an intact sealant had been recorded (p<0.001). In contrast, of those surfaces on which the sealant was noted as deficient at the outset, 22.9% were judged to have been affected by caries. This study shows that sealants should be repaired when deficient if they are to be effective.

The prevalence and effectiveness of fissure sealants in Scottish adolescents
Chestnutt IG*, Schäfer F, Jacobson APM* and Stephen KW* (*University of Glasgow Dental School, Glasgow, UK)
J Dent Res 1993, 72, 698

Prevalence of fissure sealants in children and adolescents in North Wales
Kavanagh D*, Ellwood RP*, O’Mullane DM*, Schäfer F and Nicholson JA (*University College of Cork, Ireland)
Caries Res 1994, 28, 181

Effect of toothbrush parameters on in vitro crevice cleaning
Dawson PL, Walsh JE and Raven SJ
J Dent Res 1994, 73, 164

Laboratory model for plaque removal from dental crevices by toothbrushes
Dawson PL, Walsh JE and Raven SJ
J Dent Res 1994, 73, 502

Periodontal health: CPITN as a promotional strategy
Purdell-Lewis D and Croxson LJ* (*New Zealand Dental Association, Auckland, New Zealand)
Int Dent J 1994, 44, 571-576

Community and individual involvement are essential needs in preventative programmes for periodontal health. Campaigns should be directed towards a better individual understanding of the importance of healthy gum tissues if a functional, healthy dentition is to be retained over a lifetime. Effective awareness campaigns require not only participation and education of the general public, but also all levels of health care professionals. Awareness programmes need to be carefully planned and their messages clear, non-conflicting and regularly reinforced. The complete programme should be based on, and include, specific aims, goals, strategies, monitoring and evaluation. Oral health and hygiene promotion campaigns need careful coordination between relevant agencies or institutions involved in their implementation, such as government agencies, professional associations, industry, aid groups and education organisations.

Investigation of factors influencing stain formation utilizing an in situ model
Joiner A, Jones NM and Raven SJ
Adv Dent Res 1995, 9, 471-476

In order to understand the factors of extrinsic stain formation more fully, we have developed an in situ stain model. This consists of polished bovine enamel blocks attached to partial or full dentures worn by adult volunteers for 24h per day. The dentures were cleaned twice daily with a commercial dentifrice and toothbrush, with care taken to avoid brushing the inserts. A Minolta CR321 Chroma Meter in the L*a*b* mode was used for taking reflectance measurements of the stain formed on the enamel inserts. From these values, changes in the color of the inserts were calculated and the level of stain determined. In general, the stain formed on the enamel inserts was yellow and increased in intensity and darkness with time. The enamel inserts with the largest stain increases were from smokers rather than non-smokers. No correlation was observed between amount of stain and quantity of tea and coffee consumed. When the effects of surface roughness on in situ stain formation were considered, the major variabIe in this study was found to be the location of the enamel insert in the denture rather than the surface roughness.

Hamster cheek pouch bioassay of dentifrices containing hydrogen peroxide and baking soda
Marshall M*, Kuhn JO*, Torrey CF*, Fischman S** and Cancro L (*Dermigen, Smithville, TX, USA, **SUNY, Buffalo, New York, USA)
J Am Coll Toxicol 1996,15, 45-61

The objective of this study was to determine the effects of hydrogen peroxide alone and in combination with7,12-dimethylbenza[a] anthracene (DMBA) in the oral cavity because H2O2 has been implicated as a complete carcinogen or cocarcinogen in two animal models. In the two independent studies, golden Syrian hamsters were used to evaluate the carcinogenic and cocarcinogenic potential of dentifrices containing H2O2 and NaHCO3. In the first study the cocarcinogenic potential of a dentifrice containing 0.75% H2O2/ 5% baking soda was compared with that of a commercial dentifrice with similar ingredients except baking soda and H2O2. In the second study, the cocarcinogenic potential of a dentifrice formulated with 1.5% H2O2/7.5% baking soda was compared with a mixture of 3% H2O2/baking soda. All materials were applied to the right cheek pouches of experimental animals, and the left cheek pouches were untreated. In the first study. 0.5% DMBA was administered five times weekly for 20 weeks, and the dentifrices were applied immediately after the DMBA. Dentifrices or mineral oil alone were also applied five times weekly. In the second study, 0.5% DMBA or 0.25% DMBA were applied three times weekly for 16 weeks; dentifrices (or 3% H2O2/baking soda) were applied five times weekly for 16 weeks. The dual-phase dentifrice containing 0.75% H2O2/5% baking soda was not carcinogenic and in combination with DMBA resulted in no observable acceleration of tumor onset compared with DMBA alone. In fact animals treated with 0.5% DMBA and the H2O2/baking soda dentifrice had a significantly delayed onset of tumor formation than did animals treated with DMBA alone. In the second bioassay, an increased latency period for tumor formation was observed with 0.5% DMBA and a dual-phase dentifrice containing 1.5% H2O2/7.5% baking soda, compared with 0.5% DMBA alone. With 0.25% DMBA Iatency was not affected by addition of the dualphase dentifrice. In contrast, animals receiving 0.25% DMBA and 3% H2O2/ NaHCO3 had a significantly lower rate of tumor formation and overall mass incidence. Croton oil also reduced the rate of tumor formation when applied with 0.25% DMBA. Histopathologic examination of cheek pouches revealed squamous cell carcinomas in the majority of DMBA-treated animals. Cheek pouches of DMBA-treated animals killed at interim times indicated a progression from keratotic changes and/or dyskeratosis at 6 weeks with the occurrence of carcinomas in approximately half the animals examined at 12 weeks. No significant histopathologic abnormalities were observed in animals not receiving DMBA other than slight keratosis in the oral mucosa of one or two animals per group. These results demonstrated that an oral product containing baking soda and hydrogen peroxide was not carcinogenic and that baking soda and H2O2 did not enhance the tumorigenicity of DMBA. Furthermore, the tumorigenic response of DMBA was reduced by coadministration of 3% H2O2 and sodium bicarbonate.

IMAGEM 4

Development of an in situ dental stain model
Joiner A and Jones NM
J Dent Res 1996, 75, 296

Extrinsic tooth stain after six weeks of normal dentifrice use
Macpherson LMD*, Stephen KW*, Schafer F, Joiner A (*University of Glasgow Dental Hospital and School, Glasgow, Scotland, UK)
J Dent Res 1996, 75, 223

Differential expression of type 1 cytokeratins in hamster cheek pouch epithelium following treatment with dimethylbenzanthracene
Shearer BH, McMillan MD*, and Jenkinson HF* (*University of Otago, Dunedin, New Zealand)
J Oral Pathology and Medicine 1997, 26, 470-476

Cytokeratin (CK) expression in untreated, paraffin-treated or dimethylbenzanthracine (DMBA) - treated hamster cheek pouch epithelium was investigated utilizing monoclonal antibodies AEI or AE3, which react with type I or type II CKs respectively, and by in situ hybridization utilizing type I CK-specific probes. The latter were isolated from a cDNA library of hamster cheek pouch mRNA and designated CK 13 and CK 10 based on their respective homologies (>95% amino acids) with murine CK 13 and human CK I0. Treatment of hamster cheek pouch epithelium with DMBA resulted in increased expression of type I CK, detected immunohistochemically with monoclonal AEI, but decreased expession of type II CKs detected with AE3. Despite an overall increase in type I CKs, in situ hybridization demonstrated differential expression of type I CKs with altered distribution of CK 13 mRNA and reduced expression of CK 10 mRNA, providing additional sensitive markers for DMBAassociated changes in CKs. These changes were constant at 2 to 22 weeks in the pre-neoplastic and neoplastic epithelium following the initial application of DMBA.

Lack of mutagenicity and free radical Inhibition by a H2O2 - containing dentifrice Marshall MV*, Cancro LP and Floyd RA** (*Stillmeadow Inc., Sugar Land, Texas, USA, **0klahoma Medical Research Foundation, Oklahoma City, USA) J Dent Res 1993, 72, 248 Lack of mutagenicity and free radical Inhibition by a H2O2 - containing dentifrice Marshall MV*, Cancro LP and Floyd RA** (*Stillmeadow Inc., Sugar Land, Texas, USA, **0klahoma Medical Research Foundation, Oklahoma City, USA) J Dent Res 1993, 72, 248 Osseo-integrated implants: A review of the literature Shearer BH Int Dent J 1995, 45, 261-266 The success of osseointegrated implants as a treatment option is extremely high. In recent years the emphasis in implant development has moved towards improved aesthetics. This paper reviews some of the recent advances associated with aesthetics and implant supported restorations. The techniques of bone grafting and guided tissue regeneration have allowed more ideal placement of implant fixtures in many situations. Implant companies continue to improve their components making implant supported prostheses possible for a wider variety of patients. Further advances in the management of the soft tissues, particularly the interdental papillae, are required to optimise aesthetic results. Hydrogen peroxide: A review of its use in dentistry Marshall M*, Cancro L and Fischman S** (*Dermigen, Smithville, TX USA, **SUNY, Buffalo, New York, USA) J Periodontol 1995, 66, 786-795 Several dentifrices that contain hydrogen peroxide are currently being marketed. The increased use of bleaching agents containing (or generating) H2O2 prompted this review of the safety of H2O2 when used in oral hygiene. Daily exposure to the low levels of H2O2 present in dentifrices is much lower than that of bleaching agents that contain or produce high levels of H2O2 for an extended period of time. Hydrogen peroxide has been used in dentistry alone or in combination with salts for over 70 years. Studies in which 3% H2O2 or less were used daily for up to 6 years showed occasional transitory irritant effects only in a small number of subjects with preexisting ulceration, or when high levels of salt solutions were concurrently administered. In contrast, bleaching agents that employ or generate high levels of H2O2 or organic peroxides can produce localized oral toxicity following sustained exposure if mishandled. Potential health concerns related to prolonged hydrogen peroxide use have been raised, based on animal studies. From a single study using the hamster cheek pouch model, 30% H2O2 was referred to as a cocarcinogen in the oral mucosa. This (and later) studies have shown that at 3% or less, no cocarcinogenic activity or adverse effects were observed in the hamster cheek pouch following lengthy exposure to H2O2. In patients, prolonged use of hydrogen peroxide decreased plaque and gingivitis indices. However, therapeutic delivery of H2O2 to prevent periodontal disease required mechanical access to subgingival pockets. Furthermore, wound healing following gingival surgery was enhanced due to the antimicrobial effects of topically administered hydrogen peroxide. For most subjects, beneficial effects were seen with H2O2levels above1%.

IMAGEM 5

IMAGEM 6

Cytokeratin changes in preneoplastic and neoplastic hamster cheek pouch epithelium
Shearer BH, Jenkinson HF* and McMillan HD* (*University of Otago, Dunedin, New Zealand)
J Dent Res 1996, 75, 331

Microbial contamination of toothbrushes during an in-home trial
Verran J*, Leahy-Gilmartin A*, Watson GK, Hammond K,. Huntington E and Raven J (*Manchester Metropolitan University, UK)
J Dent Res 1997, 76, 437

Microbial contamination of toothbrushes: Effect of usage period
Hammond K, Watson GK, Huntington E, Raven SJ, Verran J, and Leahy-Gilmartin A* (*Manchester Metropolitan University, UK)
J Dent Res 1997 76, 437

Comparative efficacy of three teeth-whitening dentifrices to remove and inhibit extrinsic natural dental stain
Sheth J*, Truelove R, Williams D and Garvin C (*Oracare Research, Altamonte Springs, Florida)
J Dent Res 77 (special issue):143, 1998.

The Efficacy of Tooth Whitening Dentifrices to Remove and Inhibit Natural Tooth Stain
Conforti N*, Truelove R, Sielski C*, Williams D and Garvin C (*ACCE, Williamsville, New York)
J Dent Res 77 (special issue):144, 1998.

In-Vivo and In-Vitro Studies Demonstrating the Ability of a BS&P Whitening Toothpaste to Whiten Teeth
Garvin C, Ryles C, Truelove R, Williams D and Ziemkiewicz A
J Dent Res 78 (special issue):357, 1999.

IMAGEM 7

IMAGEM 8

The Dental Faculty is an initiative designed to provide the global dental community with a medium for knowledge transfer. It will:

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