In vivo and in vitro assessment of the bleaching effectiveness of a brush-off patch containing 3.0% hydrogen peroxide

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.

Effect of conventional and power office bleaching with diode laser and led light on enamel microhardness

Aim: The present study aimed to asses enamel microhardness after office bleaching with diode laser and LED light compared to the conventional bleaching procedure. Methods: Thirty-nine human premolar teeth were collected and randomly divided into three groups regarding of the bleaching technique. Group 1: Snow O bleaching gel with LED light-curing unit; Group 2: Snow L bleaching gel with diode laser irradiation; and Group 3: Opalescence Boost bleaching gel with no light source in group 3. Enamel surface changes were evaluated in one tooth in each study group and one intact tooth as a reference under a scanning electron microscope (SEM). In the remaining samples (n=12), enamel microhardness was determined by Vickers microhardness test before and after bleaching. Data were analyzed with repeated-measures ANOVA to compare microhardness changes, followed by post hoc Tukey tests at the 0.05 significance level. Results: Enamel microhardness decreased in all the groups after bleaching, with the maximum decrease in microhardness in the Snow O bleaching group with LED light, which was significantly higher than the other groups (P=0.002). The two other groups did not exhibit any significant difference in microhardness decrease (P>0.05). Conclusion: Based on the limitations of this study, it can be concluded power bleaching with 980nm diode laser was less time-consuming compare to conventional bleaching procedure and yielded better outcomes in terms of enamel surface microhardness compared to the use of an LED light-curing unit.