RCT of a HEMA-free all-in-one adhesive in non-carious cervical lesions

Objectives: One-step self-etch adhesives are the most recent generation of adhesives introduced onto the market. The objective of this randomized controlled clinical trial was to test the hypothesis that a one-step self-etch adhesive performs equally well as a conventional three-step etch&rinse adhesive (gold standard).

Methods: Two-hundred and sixty-seven non-carious cervical lesions in fifty-two patients were restored with Gradia Direct Anterior (GC, Tokyo, Japan). These composite restorations were either bonded with the HEMA-free ‘all-in-one' adhesive G-Bond (GC, Tokyo, Japan) or with the three-step etch&rinse adhesive Optibond FL (Kerr, CA, USA). The restorations so far have been evaluated after 6 and 12 months clinical service regarding retention, marginal adaptation, microleakage, caries occurrence and sensitivity. Retention loss, severe marginal defects and/or discoloration that needed intervention (repair or replacement) and occurrence of caries were considered as clinical failures. A Logistic regression analysis with generalized estimating equations (GEE) was applied to factor in the clustered data (multiple lesions per patient).

Results: The recall rate at 1 year was 98%. The statistical analysis revealed a relatively low patient factor, indicating that supplementary information could be obtained from the additional restorations per patient. The retention rate for G-Bond was 98.5% compared to 99.3% for Optibond FL due to loss of two and one restoration, respectively. There were no significant differences between both adhesives regarding the evaluated parameters except for the higher occurrence of incisal marginal defects with G-Bond. These defects, however, were small and clinically irrelevant.

Conclusions: Regarding short-term performance, it was concluded that the simplified one-step adhesive G-Bond and the three-step Optibond FL are clinically equally successful, even though both were characterized by progressive degradation of marginal adaptation and G-Bond exhibited more small enamel marginal defects.

This study was supported by the Toshio Nakao Chair. The author was granted a PhD-fellowship of the Research Foundation–Flanders.