Vital Bleaching Influences the Bond Strength of Adhesive Systems to Enamel and Dentin: A Systematic Review and Meta-Analysis of In Vitro Studies

Abstract

SUMMARY Objective: This systematic review evaluates the influence of vital bleaching on the bond strength of adhesive systems to enamel and dentin. Methods: This review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). In vitro studies comparing the bond strength of bleached and unbleached enamel and dentin were searched at the electronic databases—PubMed/MEDLINE, Scopus, and Web of Science—with no limit on year or language. The studies were screened and had data extracted by two reviewers independently. Bond strength data were meta-analyzed using the inverse variance method and the random effect model (p≤0.05). Results: The electronic search provided 4941 eligible studies, and 52 were included in the systematic review and the meta-analysis. The global meta-analysis showed that bleaching impairs the bond strength of adhesive systems to enamel and dentin (p<0.001; mean difference [MD]: −0.96; confidence interval [CI]: −1.18 to −0.73), regardless of the bleaching agent (p<0.001; MD: −9.98; CI: −1.37 to −0.58) or substrate (p<0.001; MD: −0.89; CI: −1.12 to −0.66). The detrimental effect of bleaching on bond strength was not observed after two and three weeks after bleaching (p=0.1; MD: −0.39; CI: −0.84 to 0.65; and p=0.18; MD: −0.99; CI: −2.45 to 0.47, respectively). Conclusion: This systematic review and meta-analysis demonstrated that vital bleaching impairs the bonding of adhesive systems to enamel and dentin, and this adverse effect persists for two weeks.