Thirty-six-month clinical evaluation of different adhesive strategies of a universal adhesive

The aim of this clinical trial was to evaluate and compare the performance of a universal adhesive with different adhesive strategies in the restoration of non-carious cervical lesions (NCCLs) over a 36-month period.

One hundred sixty-five NCCLs in 35 patients (13 female, 22 male) with at least 3 lesions each were included in this study. Three groups were formed according to the adhesive strategy used (n = 55): selective-etch mode, etch-and-rinse mode, or self-etch mode of a universal adhesive, Single Bond Universal. The same nanofilled resin composite, Filtek Ultimate, was used for all restorations by a single operator. The restorations were evaluated by two calibrated examiners at baseline and at 6, 12, 18, 24, and 36 months in accordance with the modified USPHS criteria. The chi-square test was used for intergroup comparison and Cochran's Q test for intragroup comparison (∝ = 5%).

At 36 months, the recall rate was 98.1% and three restorations, one from each group, had failed because of retention loss (P > 0.05). The self-etch mode group showed 17 bravo scores for both marginal staining and marginal adaptation after 3 years, which was significantly different from the selective-etch and etch-and-rinse groups (P < 0.05). For all groups, the only statistically significant difference was found when baseline and 36-month evaluations were compared in terms of marginal staining (P = 0.000). When the marginal adaptation values at 36 months were compared with those at the baseline, statistically significant differences were found in the etch-and-rinse and self-etch mode groups (P < 0.05). Neither secondary caries nor postoperative sensitivity was observed at any recall.

All adhesive modes showed similar retention rates. Although all restorations were clinically acceptable, restorations in self-etch mode showed less satisfying performance for marginal staining and marginal adaptation.

At the end of 36 months, the Single Bond Universal adhesive received acceptable scores according to the modified United States Public Health Service (USPHS) criteria. However, clinicians should be aware that its use in self-etch application mode tends to result in marginal staining and marginal deterioration when compared with etch-and-rinse and selective-etch application modes.