Six Month Clinical Evaluation of Prolonged Solvent Evaporation of Universal Adhesive in Non-Carious Cervical Lesions: A Double-Blind Randomized Clinical Trial

Objectives: To evaluate the effect of prolonged solvent evaporation on the clinical performance of universal adhesive systems in non-carious cervical lesions (NCCLs). Materials and Methods: A total of 148 NCCLs were randomly placed in 28 subjects according to: SUP5 (Scotchbond Universal Plus adhesive [ethanol-water] evaporated for 5 s); SUP25 (SUP evaporated for 25 s); GBU5 (Gluma Bond Universal adhesive [acetone-water] evaporated for 5 s); GBU25 (GBU evaporated for 25 s). Restorations were evaluated at baseline and 6 months, using the updated FDI criteria. Appropriate statistical analyses were performed (α = 0.05). Results: The recall rate was 100% at 6 months. The retention rates were 83.4% for SUP5, 97.3% for SUP25, 100% for GBU5, and 97.3% for GBU25. A significantly lower retention rate was observed for SUP5 compared to GBU5 (p = 0.04). No significant differences among the groups were observed when secondary parameters were evaluated (p > 0.05). Conclusions: Prolonged solvent evaporation time, whether for ethanol-water or acetone-water based universal adhesives, did not improve their clinical performance in NCCLs after 6 months. However, the lowest retention rate was observed in the ethanol-water adhesive when evaporated for only 5 s. Clinical Significance: Extended solvent evaporation time for universal adhesives does not significantly affect their short-term clinical performance.