Universal Adhesive Brands Functional Performance in Non-Carious Cervical Lesions: 18- to 48-Months Systematic...

Universal adhesives (UAs) exhibit considerable versatility; however, no single commercial product has attained recognition as a clinical gold standard. This study evaluated the functional performance, retention, and marginal integrity of various UA brands in non-carious cervical lesion (NCCL) restorations and examined the effects of different adhesion strategies. A search of electronic databases was conducted for randomized clinical trials (RCTs) published between 2015 and 2025. Only RCTs that assessed the retention and marginal integrity of UAs with follow-ups of 18-48 months, using the USPHS/FDI criteria, were included. This review was registered with PROSPERO (CRD420251026490) and adhered to PRISMA 2020 and PICOS guidelines. Risk of bias was evaluated using the RoB 2 tool; statistical significance was defined as p < 0.05. Of 251 records screened, 23 met the eligibility criteria, resulting in the inclusion of 21 RCTs. Sixteen UA brands exhibited no clear differences in performance outcomes. Etch-and-rinse (ER) and selective enamel-etching (SEE) strategies achieved higher retention rates (median up to 100%; USPHS, p < 0.001), while the self-etch (SE) approach demonstrated lower and more variable retention (median 87.0%). Marginal integrity remained consistently high across all strategies (median 100%; p > 0.05). Although ER and SEE strategies significantly enhance long-term retention, no UA brand showed consistent superiority to be considered a gold standard.