24-month clinical evaluation in non-carious cervical lesions of a two-step etch-and-rinse adhesive applied using a rubbing motion

The aim of this clinical trial was to evaluate the effects of application mode on the clinical performance of a two-step etch-and-rinse adhesive in class V cavities over 24 months. Forty patients with at least three similar-sized non-carious cervical lesions participated in this study. A total of 120 restorations with Prime & Bond NT were placed, 40 in each group. The adhesive was applied with no rubbing action, with slight rubbing action, or with vigorous rubbing action. The restorations were placed incrementally using the composite resin Esthet-X. The restorations were evaluated at baseline and after 6, 12, and 24 months following the modified United States Public Health Service criteria. Statistical analysis was conducted using Friedman repeated measures analysis of variance by rank and using the Wilcoxon signed-rank test for significance at each pair (α = 0.05). The 24-month retention rates of Prime & Bond NT were 82.5% for the no rubbing group, 82.5% for the slight rubbing group, and 92.5% for vigorous rubbing group. No significant difference in the retention rates in each recall period was detected among groups (p > 0.05); however, the retention rates in the 24-month recall was statistically lower than the baseline only for no rubbing or slight rubbing groups. The use of a vigorous application mode can be a clinical approach to improve the retention of restorations placed in non-carious cervical lesions.