Bond strength of self-adhesive flowable composite resins to dental tissues: A systematic review and meta-analysis of in vitro studies

Although the clinical use of self-adhesive flowable composite resins is convenient, the decision to use flowable or conventional composite resin remains controversial.The purpose of this systematic review and meta-analysis was to assess the in vitro bond strength of self-adhesive flowable composite resins to enamel or dentin compared with conventional composite resins using etch-and-rinse or self-etch adhesive systems.Two independent reviewers performed searches in the PubMed (MEDLINE), Cochrane Wiley, Web of Science, Scopus, and Google Scholar databases for studies reporting on the bond strength of self-adhesive flowable and conventional composite resins to enamel and dentin published from January 2010 up to September 2020. A meta-analysis software program was used for the meta-analysis. Comparisons were conducted using standardized mean differences considering the random-effects model (α=.05).Twenty-two studies were considered for the meta-analysis. Immediate and long-term bond strength to enamel was improved when a conventional composite resin was used in combination with an adhesive system (P.001). Bond strength to dentin was improved by using an adhesive system in combination with a conventional composite resin (P.001).The bond strength of self-adhesive flowable composite resins is lower than that of conventional composite resins, indicating limited ability to bond to enamel and dentin.