Assessment of color changes and adverse effects of over-the-counter bleaching protocols: a systematic review and network meta-analysis.

OBJECTIVES: To assess color change efficacy and the adverse effects of varied over-the-counter (OTC) bleaching protocols. METHODOLOGY: The study included randomized clinical trials evaluating color changes from OTC bleaching agents. Nine databases were searched, including the partial capture of the grey literature. The RoB2 tool analyzed the individual risk of bias in the studies. Frequentist network meta-analyses compared treatments through common comparators (∆Eab* and ∆SGU color changes, and tooth sensitivity), integrating direct and indirect estimates and using the mean and risk differences as effect measures with respective 95% confidence intervals. The GRADE approach assessed the certainty of the evidence. RESULTS: Overall, 37 remaining studies constituted the qualitative analysis, and ten composed the meta-analyses. The total sample included 1,932 individuals. ∆Eab* was significantly higher in groups 6% hydrogen peroxide (HP) strips (≥ 14 h). ∆SGU was significantly higher in groups at-home 10% carbamide peroxide (CP) (≥ 14 h), followed by 6% HP strips (≥ 14 h) and 3% HP strips (≥ 14 h). At-home 10% CP (7-13 h) and placebo showed lower risks of tooth sensitivity without significant differences between these treatments. CONCLUSION: Considering the low level of evidence, OTC products presented satisfactory short-term effects on tooth bleaching compared to the placebo, with little to no impact on dentin hypersensitivity and gingival irritation. CLINICAL RELEVANCE: OTC products are proving to be practical alternatives for tooth whitening. However, patients should be advised about the possible risks of carrying out such procedures without professional supervision.

Avaliação in silico da afinidade de drogas ao receptor TRPA1 como preditor para o manejo farmacológico da sensibilidade provocada pelo clareamento dentário / In silico assessment of drug affinity to the TRPA1 receptor as a predictor for the pharmacological management of sensitivity caused by tooth whitening

Introdução: Reduzir a sensibilidade do clareamento dental em consultório representa um desafio para os profissionais. Pesquisadores associaram o bloqueio do receptor de dor TRPA1 com a redução da sensibilidade ao clareamento. No entanto, a afinidade química dos analgésicos/anti-inflamatórios para o TRPA1 ainda precisa ser averiguada. Objetivo: Realizar uma triagem virtual de múltiplos medicamentos (analgésicos e antiinflamatórios) para verificar a afinidade química pelo receptor TRPA1. Metodologia: A estrutura cristalina das proteínas do receptor TRPA1 foi recuperada do Protein Data Bank. Os códigos SMILES dos ligantes foram extraídos do PubChem. A energia de ligação do complexo foi obtida em ∆G - kcal/mol pelo AutoDock Vina© e replicada nos servidores SwissDock©, Dockthor© e CbDock©. LigPlus© confirmou os sítios de ligação. Resultados: Apesar dos antagonistas dos receptores analisados apresentarem alta afinidade, codeína e dexametasona apresentaram regularidade em todos os servidores, mesmo apresentando valores de energia de ligação de -7,9 kcal/mol para codeína e -8,1 kcal/mol para dexametasona. Conclusão: A codeína e a dexametasona podem ser drogas potenciais para controlar a sensibilidade ao clareamento dental caso atinjam o receptor TRPA1 da polpa dentária (AU).

Introduction: Reducing in-office tooth bleaching sensitivity represents a challenge for professionals. Researchers have associated the block of the pain receptor TRPA1 with reducing bleaching sensitivity. However, the chemical affinity of analgesic/antiinflammatory drugs to the TRPA1 needs to be verified. Objective: To perform a virtual screening of multiple drugs (analgesic and anti-inflammatory drugs) to verify chemical affinity for the TRPA1 receptor. Methodology: The crystal structure of the TRPA1 receptor proteins was retrieved from the Protein Data Bank. The SMILES codes of the ligands were extracted from PubChem. The binding energy of the complex was obtained in ∆G - kcal/mol by AutoDock Vina© and replicated in the webservers SwissDock©, Dockthor©, and CbDock©. LigPlus© confirmed the binding sites. Results: Although the receptor antagonists analyzed showed high affinity, codeine and dexamethasone showed regularity among all servers, even showing binding energy values of -7.9 kcal/mol for codeine and -8.1 kcal/mol for dexamethasone. Conclusion: Codeine and dexamethasone may be potential drugs to manage tooth bleaching sensitivity if they reach the dental pulp TRPA1 receptor (AU).

Assessment of cytotoxic and genotoxic effects of conventional and whitening kinds of toothpaste on oral mucosa cells.

OBJECTIVE: This study aimed to evaluate possible DNA damages to oral epithelial cells exposed to whitening kinds of toothpaste considering the effect of conventional non-whitening toothpaste. MATERIALS AND METHODS: Sixty volunteers were assigned into three experimental groups, each of them using a different regular toothpaste for the initial 2 months, followed by the use of whitening kind of toothpaste of the same brand for next 2 months. The oral epithelial cells were sampled prior and 30, 60, 90 and 120 days after the beginning of the use of tested kinds of toothpaste. Chromosomal damages were analyzed by micronucleus assay. RESULTS: For just one kind of tested whitening toothpaste was observed the significant increase in the number of micronucleated cells after 60 days of use compared values obtained 60 days of usage of conventional non-whitening toothpaste (6.35 ± 3.67 and 2.8 ± 1.91; p < .05). There was no statistically significant difference in other micronucleus assay endpoints between tested types of toothpaste at either of the sampling times during the period of toothpaste application. CONCLUSIONS: Based on the results, it can be concluded that the use of certain whitening kinds of toothpaste may cause a limited biologically insignificant genotoxic effect on buccal epithelial cells.

Assessment of efficacy and post-bleaching sensitivity of home bleaching using 10% carbamide peroxide in extended and non-extended bleaching trays.

AIM: This study aimed to compare the effect of extended margin and conventional bleaching trays on tooth bleaching and tooth sensitivity. METHOD AND METHODS: Twenty subjects (18-56 years) were investigated in a split arch design clinical study that was conducted in a general dental practice. Each subject received a custom made bleaching tray and 10% carbamide peroxide gel. The bleaching trays had the borders extended 5 mm beyond the gingival margins on the right side and finished just at the gingival margin on the left side. Shade change and tooth sensitivity were the primary outcomes studied and analysed in this study. The shade of the six upper and lower anterior teeth was assessed using a value-ordered shade guide before, one week and two weeks after treatment. Sensitivity was self-assessed using a visual analogue scale (VAS) at the end of the first and second weeks of the study. RESULTS: At the end of week two, the mean shade change was 5.01 (± 3.37) and 5.10 (± 3.36) for teeth covered by extended and non-extended tray design, respectively. The mean VAS sensitivity scores for teeth covered by extended and non-extended tray design were 0.96 (± 1.39) and 0.66 (± 0.96), respectively. There was no significant statistical difference between the two designs at any assessment point with regard to shade change and sensitivity (p >0.05). CONCLUSIONS: It can be concluded that an extended tray design confers no superior effect in terms of the whitening outcome achieved or in reducing levels of sensitivity. Thus, both tray designs can be used depending on a dentist's personal preference.

Assessment of the effect of casein phosphopeptide-amorphous calcium phosphate on postoperative sensitivity associated with in-office vital tooth whitening.

The aim of this study was to evaluate the efficacy of tooth mousse containing 10% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) in reducing tooth sensitivity associated with in-office vital tooth whitening. In-office tooth whitening was performed for 51 participants using 35% hydrogen peroxide gel in a single visit. After the procedure, each participant was randomly assigned to one of three groups: gel without desensitizing agent (n=17), gel with 2% sodium fluoride (n=17), gel with 10% CPP-ACP (n=17). A small amount of the desensitizing gel assigned for each participant was applied directly on the labial surfaces of teeth and left undisturbed for three minutes. The participants were asked to apply the gel assigned to them for three minutes twice daily after brushing their teeth, and to continue this for 14 days. The participants were asked to return for follow-up visits after 24 hours and on days 3, 7, and 14, at which time teeth shade changes were assessed by one evaluator using a value-oriented Vita classic shade guide. The incidence, duration, and intensity of tooth sensitivity experienced was self-assessed on a daily basis for the 14-day study period using a visual analog scale (VAS). The effect of the three gels on tooth sensitivity was assessed using one-way analysis of variance and a χ (2) test (α=0.05). The general linear model was used to compare intensity-level differences in the three studied groups and for shade stability over the follow-up period. The results of this study showed that all three gels decreased the intensity of sensitivity associated with tooth whitening. The intensity of sensitivity was lower in the fluoride group than in the other two groups; however, it was not statistically significant (p=0.112 and p=0.532 on day 1 and day 2, respectively). The average shade change was 6.8. None of the tested materials affected the efficacy of tooth whitening, but the shade change among the fluoride group showed more color stability than that of the other two groups. This study suggested that using a gel after tooth whitening can reduce the intensity of tooth sensitivity associated with in-office whitening procedures without affecting the efficiency of tooth whitening. However, it failed to demonstrate that using a 10% CPP-ACP could provide additional therapeutic benefits.

Assessment of the release of mercury from silver amalgam alloys exposed to different 10% carbamide peroxide bleaching agents.

This in vitro study assessed the amount of mercury (Hg) released from a silver amalgam alloy following the application of different 10% carbamide peroxide bleaching agents. A total of 30 specimens (2 mm thick x 4 mm in diameter) were stored in deionized water at 37°C for 7 days. Next, the control group (n = 10) remained in the deionized water for 15 days, while the remaining samples were exposed to 1 of 2 bleaching agents (n = 10) for 8 hours daily (total exposure = 120 hours); for the remaining 16 hours, specimens in the test groups were stored in deionized water at 37°C under relative humidity. After this period, the quantity of Hg in the deionized water was assessed (using atomic absorption spectrophotometry) and compared to the amount of Hg at baseline. The results indicate that exposing amalgam alloys to bleaching agents released greater amounts of Hg compared to exposing samples to deionized [corrected] water.

Assessment of tooth sensitivity using a desensitizer before light-activated bleaching.

UNLABELLED: CLINICAL OBJECTIVE: This clinical study evaluated whether the use of a desensitizing agent (5% potassium nitrate/2% sodium fluoride) before in-office light-activated bleaching decreased this sensitivity. METHODS: Before in-office bleaching with 35% hydrogen peroxide gel (three applications, 15 minutes each) associated with an LED/laser unit, clinicians applied a placebo gel or the desensitizing agent on the buccal surfaces of all participants. They repeated this protocol one week later. Patients recorded their tooth sensitivity on a 0-to-4 scale. The authors used one-way repeated measures ANOVA to compare the tooth color changes and non-parametric statistics to compare the different percentages of patients with tooth sensitivity and the levels of tooth sensitivity in the different periods of time between groups (α=0.05). RESULTS: The use of a desensitizing gel did not affect the bleaching efficacy. Eighty percent and 100% of the participants from the experimental and placebo groups, respectively, experienced tooth sensitivity (p>0.05). The intensity of sensitivity was similar immediately after bleaching for both groups (p>0.05). After 24 hours, lower sensitivity was reported in the experimental group, while most of the participants from the placebo group experienced tooth sensitivity (p<0.05).

An exposure-based risk assessment approach to confirm the safety of hydrogen peroxide for use in home tooth bleaching.

Hydrogen peroxide has a long history of safe use in a wide variety of medical and consumer products, including oral care products. The use of hydrogen peroxide in tooth bleaching has been extended to home use. Because this represents a new use, questions have been raised regarding safety, particularly the potential for peroxide tooth-whitening products to increase the risk of oral cancer in high-risk individuals (e.g., smokers and drinkers). These concerns are based on limited experimental data in animals that hydrogen peroxide has extremely weak tumor promoting activity and a lack of publicly available data on exposure to peroxides from the home use of tooth-whitening products. This paper provides a weight-of-evidence cancer hazard characterization for hydrogen peroxide and presents a quantitative risk assessment that confirms a favorable human safety profile risk associated with low levels of exposure to hydrogen peroxide from the use of tooth-whitening products. This includes a lack of tumor promotion risk which is important because tooth-whitening products are often used by chronic smokers and drinkers, who may represent a susceptible subpopulation because of their exposure to other known carcinogens.

Teaching nightguard bleaching and other tooth-whitening procedures in North American dental schools.

Tooth-whitening using carbamide peroxide delivered in a custom-fitted tray (nightguard bleaching) is a relatively new procedure, yet it is currently one of the most commonly used types of esthetic dental treatment in private practice. This study determined the extent that nightguard bleaching (NGB) has been included in dental school curricula. All sixty-five dental schools in North America were surveyed about curriculum content and treatment protocol for the use of nightguard and other bleaching procedures, generating an 82 percent response. The survey covered eighteen subject areas related to NGB ranging from clinical requirements and indications to products and recall intervals used. The most commonly taught tooth-whitening procedure was NGB, which was most often taught by operative and restorative faculty. Although no schools had clinical requirements for NGB, 92 percent taught it. The most common indications for NGB were esthetic shade change and pre-restorative lightening of teeth. Unrestored caries, defective restorations, and pre-existing sensitivity were common contraindications. Most schools do not use a specific NGB consent form, but most use written patient instructions. Most schools use at least two different NGB products, bleach for two to four weeks, and use reservoired and scalloped trays. An average of 25 percent of NGB patients were estimated to develop sensitivity, for which treatment recommendations include fluoride, desensitizing toothpaste, and reduced exposure time. Curriculum time and safety concerns were reasons for not teaching NGB (8 percent schools). Most schools indicated that the relative importance of NGB in the curriculum was increasing.

Current status of nightguard vital bleaching.

Indications for using a 10% carbamide peroxide material in a custom-fitted tray to whiten teeth include teeth discolored from aging, chromogenic foods and drinks, and smoking, and also brown fluorosis-stained teeth, single dark teeth, and tetracycline-stained teeth. Tetracycline-stains may require 2 to 6 months of nightly treatment, whereas after discolorations generally resolve in 2 to 6 weeks. After an initial relapse in the first 2 weeks after the end of treatment, color tends to be stable for 1 to 3 years, with some treatments being permanent. The ADA has approved only six 10% carbamide peroxide materials, which have extensive research and publications on safety and efficacy. Considering the average cost of $196 per arch, and the noninvasive nature of this treatment, nightguard vital bleaching is probably the safest, most cost-effective, patient-pleasing method to improve the appearance of a smile. However, it should be supervised by a dentist for the proper examination, diagnosis of the cause of discoloration, treatment options, and fabrication and fitting of the carrier. Sensitivity during whitening may be treated with fluoride and potassium nitrate.