Bleaching effectiveness of hydrogen peroxide containing titanium dioxide: A systematic review and meta-analysis.

OBJECTIVES: This systematic review and meta-analysis aimed to evaluate the efficacy of incorporating titanium dioxide (TiO(2)) into a hydrogen peroxide (HP) gel to increase bleaching effectiveness. DATA SOURCES: A comprehensive search was conducted in the PubMed, Web of Science, and Scopus databases through February 12, 2024. STUDY SELECTION: The eligibility criteria included studies comparing the bleaching effectiveness of HP alone to HP with incorporated TiO(2). The risk of bias for in vitro studies was assessed using the RoBDEMAT tool, while in vivo studies were evaluated using the Cochrane Collaboration tool. Meta-analyses were conducted for color difference (DeltaE(00)) and whiteness index for dentistry (WI(D)). The mean difference (MD) and 95% confidence interval (CI) for the DeltaE(00) and DeltaWI(D) values were calculated using a random-effects model (alpha=0.05). RESULTS: A total of 17 studies were included in this systematic review, and 5 were included in the meta-analysis. Among the 17 eligible studies, 11 were in vitro studies, and 6 were in vivo studies. The commonly used HP concentrations were 6% and 35%, and the concentrations of incorporated TiO(2) ranged from 0.2% to 10%. The meta-analysis demonstrated that incorporating TiO(2) into HP gels resulted in significantly greater DeltaE(00) values (P=0.04; MD=0.50; 95% CI: 0.01 to 0.98) and DeltaWI(D) values (P=0.003; MD=2.28; 95% CI: 0.75 to 3.80) than did using HP gels alone, with the DeltaWI(D) exceeding the perceptible threshold. CONCLUSIONS: HP gels with TiO(2) showed increased color and whitening index changes. However, standardized bleaching protocols, consistent color evaluation, and post-bleaching monitoring are needed for validation and study comparability. TiO(2) properties (particle size, shape, crystal phase) significantly affect gel performance, requiring further research to determine optimal parameters. CLINICAL RELEVANCE: Using a low-concentration HP gel with TiO(2) may be a promising alternative to high-concentration HP bleaching, potentially minimizing the side effects.