Prospective, randomized clinical trial evaluating the clinical performance of a new universal adhesive in Class I and Class II restorations at 1 year.

Objective: This randomized controlled trial compared the 1-year clinical efficacy of Scotchbond Universal Adhesive Plus (SBU+) with that of its predecessor Scotchbond Universal Adhesive (SBU) to restore Class I and Class II preparations using the self-etch strategy in adult patients.

Materials and methods: Fifty-one subjects participated in this study. Two posterior teeth in each subject were randomized to a restoration with SBU+ or to a restoration with SBU (control) using the self-etch strategy. Teeth were restored with Filtek Universal Restorative. Restorations were evaluated at baseline, 6 months and 1 year using the FDI criteria. The Wilcoxon signed-rank test was used to compare outcomes.

Results: No restorations were graded as "Insufficient/Unsatisfactory" or "Poor" for any of the FDI criteria at the baseline, 6-month, or 1-year visits. At 1 year the retention rate was 100% for both SBU+ and SBU. For fracture of the restorative material 42/44 SBU+ restorations (95%) and 44/44 SBU restorations (100%) were graded "Excellent/Very Good" (p > 0.05). All restorations were clinically acceptable for marginal adaptation at 1 year with no statistical differences between the two adhesive materials. There were no recurrent caries lesions at the 1-year visit.

Conclusions: The clinical efficacy of the SBU+ at 1-year was not different to that of its predecessor SBU in Class I and Class II restorations of adult patients using the self-etch strategy.

Clinical relevance: The two dental adhesives used in this clinical trial showed excellent results in posterior restorations at 1 year without using a separate phosphoric etching step.