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Objectives: This meta-analysis was performed to evaluate the efficacy of potassium nitrate and sodium fluoride as desensitizing agents during tooth bleaching treatment., Data, Sources and Study Selection: An electronic systematic literature search was conducted in Cochrane Center Register of Controlled Trials, MEDLINE (PubMed) and EmBase in April, 2014 in English and without time restrictions. Study information extraction and methodological quality assessments were accomplished by two reviewers independently. Methodological quality was assessed by using the "Criteria for judging risk of bias in the 'Risk of bias' assessment tool". Dichotomous data was summarized by odds ratio (OR) with 95% confidence interval (CI) and continuous data was summarized by mean difference (MD) or standardised mean difference (SMD) with 95% confidence interval (CI). Statistical analyses were carried out by using Review Manager 5.2. For evaluation of percent of patients experiencing tooth sensitivity (POTS), the pooled OR of desensitizers vs. placebo was 0.45 (95% CI: 0.28-0.73, P=0.29). The pooled SMD of desensitizers vs. placebo was -0.47 (95% CI: -0.77 to -0.18, P=0.13) in evaluation of level of tooth sensitivity (LOTS). The results of shade evaluation remained inconsistent by evaluating subjective shade guide unit difference (ΔSGU or SGU) and objective colour difference (ΔE)., Conclusions: This meta-analysis was performed to evaluate the efficacy of desensitizing agents, potassium nitrate and sodium fluoride, for tooth bleaching treatments. Potassium nitrate and sodium fluoride reduce tooth sensitivity while no consistent conclusion of tooth colour change was found., Clinical Significance: Tooth sensitivity is a typical side effect associated with tooth bleaching procedures. Potassium nitrate and sodium fluoride are used widely to treat tooth sensitivity. This meta-analysis was performed to evaluate the efficacy of potassium nitrate and sodium fluoride as desensitizing agents during tooth bleaching treatment., (Copyright © 2015. Published by Elsevier Ltd.)

Background: In an in vivo study, the authors tested the hypothesis that no difference in enamel surface roughness is detectable either during or after bleaching with a high-concentration in-office whitening agent., Methods: The authors performed profilometric and scanning electron microscopic (SEM) analyses of epoxy resin replicas of the upper right incisors of 20 participants at baseline (control) and after each bleaching treatment with a 38 percent hydrogen peroxide whitening agent, applied four times, at one-week intervals. The authors used analysis of variance for repeated measures to analyze the data statistically., Results: The profilometric analysis of the enamel surface replicas after the in vivo bleaching protocol showed no significant difference in surface roughness parameters (P > .05) compared with those at baseline, irrespective of the time interval. Results of the correlated SEM analysis showed no relevant alteration on the enamel surface., Conclusions: Results of this in vivo study support the tested hypothesis that the application of a 38 percent hydrogen peroxide in-office whitening agent does not alter enamel surface roughness, even after multiple applications., Clinical Implications: The use of a 38 percent hydrogen peroxide in-office whitening agent induced no roughness alterations of the enamel surface, even after prolonged and repeated applications.

Background: A new restorative called a "giomer composite" has been introduced. The authors conducted a study to determine retention, anatomical form, caries, staining, marginal discoloration, marginal adaptation, surface roughness and sensitivity of giomer compared with those of a microfilled composite., Methods: The authors placed 40 sets of restorations randomly in canines and premolars in vivo. They used a giomer composite and a microfilled composite in erosion/abrasion/abfraction Class V lesions that were not altered with rotary instruments. They placed the restorations according to manufacturer's recommendations, and two calibrated examiners evaluated the restorations independently using modified U.S. Public Health Service criteria at baseline and at six, 18 and 36 months. The lesions receiving the restorations did not differ from each other in the amount of circumferential enamel present, the percentage of the surface area of dentin or lesion type., Results: There were no differences in the restorations at baseline, an evaluation made two weeks after placement. At 36 months, the giomer and microfilled composite restorations were not significantly different from one another in any of the eight criteria evaluated. The percentage agreement between examiners was at least 83 percent for each criterion in each evaluation period., Conclusions: Both the giomer and the microfilled composite used in this study meet the clinical portion of the Acceptance Program Guidelines for Dentin and Enamel Adhesives Materials established by the American Dental Association., Clinical Implications: Both the giomer and the microfilled composite used in this study can be used with confidence in Class V lesions.

Background: Vital tooth bleaching for esthetic reasons has gained in popularity during the last few years. However, few studies have investigated the efficacy of daytime bleaching products. The purpose of this double-blind in vivo study was to evaluate the efficacy of 20 percent carbamide peroxide, or CP, and 7.5 percent hydrogen peroxide, or HP, during daytime use. The degree of color change, any color relapse, and tooth or gingival sensitivity were evaluated., Methods: Twenty-four patients participated in this study. The bleaching gels were randomly applied to the right and left maxillary anterior teeth. Patients were shown how to place the two bleaching agents in a custom tray for one hour, twice a day for two weeks. Patients returned in one, two, three, six and 12 weeks for color evaluation with the colorimeter and shade guides as well as to have color slide photographs taken. The authors evaluated sensitivity by asking the patients to record daily for 21 days any tooth or gingival sensitivity they experienced., Results: Use of the 20 percent CP resulted in significantly more lightness than the 7.5 percent HP during the first 14 days of the study, but at the end of the study, there was no significant difference between products with regard to tooth lightness. In addition, the authors found no statistically significant difference between products with regard to gingival or tooth sensitivity., Conclusions: Both CP and HP are effective at-home bleaching agents when daytime bleaching is preferred., Clinical Implications: Dentists who choose to use daytime bleaching can select either CP or HP.

Background: The purpose of the study described here was to determine the in vivo degradation rate of 10 percent carbamide peroxide, or CP, gel in bleaching trays. The degradation rate indicates the remaining concentration of the active agent on the facial surfaces at various intervals., Methods: The researchers fabricated bleaching trays with 0.5-millimeter reservoirs and loaded them with a 10 percent CP whitening gel. The tray was seated in place in 15 patients for six different intervals that ranged from 15 seconds to 10 hours. When the tray was removed, three samples were collected from each patient: the gel remaining in the tray; the adherent gel scraped from the teeth; and a "grab" sample from the reservoir of tooth no. 8. The researchers analyzed these samples for CP according to the method specified by the U.S. Pharmacopeial Convention., Results: The percentage of CP recovered decreased as the intervals increased: 87 percent at 15 seconds, 10 percent at 10 hours. Log of tray, teeth and grab samples, respectively, at 15 seconds were 0.94, 0.98 and 0.96 and at 10 hours were -0.13, -0.38 and 0.11. The first-hour degradation rate for tray, teeth and grab samples, respectively, was 2.0 times, 3.6 times and one time the rate during the next nine hours. The within-subject repeatability of the samples was excellent., Conclusions: The degradation rate of CP during the bleaching process is biexponential. In the tray and teeth samples, the degradation rate was accelerated during the first hour. Further research is needed to determine the cause of this acceleration., Clinical Implications: The active agent in CP bleaching gel is available in bleaching trays for more than 10 hours. After two hours, more than 50 percent of the active agent is available, and 10 percent is available after 10 hours.

At least four cervical erosion/abrasion lesions were restored with glass ionomer materials in 30 patients. Some restorations were finished in 15 minutes, and some were finished 24 hours after placement. No significant differences were found after five years.