Self-adhesive flowable composite resins and flowable composite resins in permanent teeth with occlusal cavities: A systematic review and meta-analysis

Objectives: To compare the clinical performance (retention, secondary caries, marginal adaptation, marginal discoloration, and postoperative hypersensitivity) of self-adhesive flowable composite resins (SAFCs) and flowable composite resins (FCs) in permanent teeth with occlusal cavities.Data: Randomized controlled trials (RCTs) of SAFCs versus FCs with a follow-up length of at least one year. No restrictions were placed on language or publication date.Sources: Five databases, including PubMed, Embase, Web of Science, Scopus, and the Cochrane Central Register of Controlled Trials, were searched manually by browsing ten related journals. On 14 June 2023, all electronic and manual searches were updated.Study selection: Five RCTs with 138 participants were included. Cochrane's risk of bias tool (2.0) was implemented in selected studies, and the GRADE tool was utilised to evaluate the evidence quality. To summarize the effects of the treatments and pool the data, a random-effects model was used.Conclusions: According to the modified United States Public Health Service Evaluation (USPHS) criteria, there was no discernible difference between the groups during the two-year follow-up period (maximum follow-up time). Nevertheless, FCs applied with the etch-and-rinse mode demonstrated superior marginal adaptation and marginal discoloration at the two-year follow-up (relative risk = 3.21 [1.50 to 6.83], 3.40 [1.10, 10.48]). The evidence for marginal discoloration at any recall time and marginal adaptation at the one-year follow-up was graded as moderate quality due to inconsistency. Moreover, low-quality evidence for marginal adaptation at twoyear follow-up was due to imprecision and inconsistency.Clinical significance: SAFCs exhibited clinical performance comparable to that of FCs in occlusal cavities. Further high-quality clinical trials are needed to provide solid evidence to support the clinical application of SAFCs. Registration: PROSPERO (CRD42022374983).