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

Abstract

Clinical Relevance Vital bleaching impairs the bonding of adhesive systems to enamel and dentin. Thus, restoration placement should be delayed for at least two weeks after completion of bleaching procedures. 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.

In Vitro Investigation of the Effects of Various Reducing Agents on Dentin Treated with Hydrogen Peroxide

“…The reduction in the bond strength of adhesive restorations to the tooth structure after tooth bleaching is a major concern in clinical settings, and this is not limited to enamel but also to dentin, particularly in cases where the bleaching material comes into direct contact with dentin, such as the walking bleach technique. The decrease in bond strength is attributed to the presence of active chemicals and highly reactive residual oxygen radicals from the bleaching agent, which interfere with resin bonding, inhibit resin polymerization, and/or increase resin porosity in resin-based restorative materials placed immediately after bleaching [ 5 , 6 ].…”