Is clinical behavior of composite restorations placed in non-carious cervical lesions influenced by the application mode of universal adhesives? A systematic review and meta-analysis.

Objective: To answer the following PICOS question: "Is the risk of retention loss, marginal discoloration, marginal adaptation and postoperative sensitivity (POS) equal for etch-and-rinse (EAR) compared to self-etch (SE) or selective-enamel etch (SEE) mode when restoring non carious cervical lesions (NCCLs) with universal adhesives?".

Methods: PubMed, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, LILACS, OpenGrey and Google Scholar™ were searched. Randomized controlled clinical trials in which resin composites and universal adhesives were used for restoration of NCCLs were considered. Cochrane Risk of Bias Tool was used to assess the risk of bias. Meta-analyses were performed using Revman; random-effects models were applied, and heterogeneity was tested using the I index. The significance level was set at p < 0.05. Certainty of evidence was assessed by GRADE tool.

Results: After screening, 20 articles were included in qualitative, while 14 articles were used for quantitative synthesis. Twelve studies ranked as "low", while 8 studies scored as "unclear" for risk of bias. At 12- and 18/24-months the risk for retention loss was higher for SE than for EAR groups (p = 0.005; RR = 0.22, 95% CI [0.08, 0.63],[moderate certainty of evidence and p = 0.0002; RR = 0.32, 95% CI [0.17, 0.58], moderate certainty of evidence, respectively). No significant differences were observed for marginal discoloration and adaptation (p > 0.05). The probability of POS occurrence was less in SE than in EAR groups (RR = 2.12, 95% CI [1.23, 3.64], moderate certainty of evidence). The certainty of evidence for other outcomes was scored as "low" or "moderate", depending on the follow-up period.

Significance: Using universal adhesives in EAR or SEE mode provides more predictable retention, while SE strategy reduces the risk of POS occurrence.