Clinical performance of different adhesion strategies in non-carious cervical lesion restorations: A four-year randomized clinical trial.

Objective: To evaluate the retention rate and other clinical criteria of four different restorative techniques for non-carious cervical lesions (NCCLs) after 4 years.

Methods: This is a prospective, randomized, double-blind, and split-mouth study evaluating four different adhesion strategies in non-carious cervical lesion restorations: adhesive restorative system (Scotchbond Universal Adhesive/Filtek Z350XT) without (SBU) and with selective enamel acid-etching (E-SBU), resin-modified glass-ionomer cements (Vitremer; RMGIC), and ethylenediaminetetraacetic as acid pretreatment (E-RMGIC). In total, 200 restorations were placed in 50 patients. Good health, no allergies to dental products, adequate oral hygiene were inclusion criteria. Pregnancy, active caries, use of desensitizers/fluoride, orthodontic appliances, and severe bruxism were exclusion criteria. All restorations were scored regarding retention, marginal integrity, marginal discoloration, surface texture, wear, secondary caries, anatomical form, surface staining, color match, and inflammation of gingival tissue marginal adaptation, using modified United States Public Health Service (USPHS) criteria at baseline and after 1, 2, 3 and 4 years. Kruskal-Wallis, Friedman, and Wilcoxon were used (p < 0.05).

Results: In total, 40 patients returned for the follow-up. RMGIC and E-RMGIC presented more alteration in surface texture than SBU and E-SBU. SBU had lower retention at four years than at baseline. Decreased alpha scores for marginal integrity and marginal discoloration were observed for all groups after four years when compared to baseline. Survival curves, related to retention, presented no statistical differences among groups (p = 0.315).

Conclusions: NCCLs restored with ionomer had more reduction in surface luster than resin composite restorations. The use of selective enamel etching promoted less loss of retention for universal adhesive. The increase of initial marginal defects occurred for all types of adhesion strategies.

Clinical Relevance: The use of selective enamel etching cause less loss of retention for universal adhesive used in NCCL. Initial marginal defects occur for all types of adhesion strategies after four years.