Clinical effectiveness of contemporary adhesives for the restoration of non-carious cervical lesions. A systematic review

ObjectivesThe aim of this systematic review was to evaluate the clinical effectiveness of contemporary adhesives for the restoration of non-carious cervical lesions (NCCLs) in terms of restoration retention as a function of time.MethodsMedline Ovid and IADR abstracts were reviewed for NCCLs clinical trials from 1950 to 2013. The reference list of all eligible trials and relevant review articles was checked to find additional studies. The review did not have any language restrictions. Only randomized controlled clinical trials that evaluated at least two adhesives for a follow-up period of at least 18 months were included. Materials with adhesive potential were categorized into 6 main classes: 3-step etch&rinse adhesives (3E&Ra's), 2-step etch&rinse adhesives (2E&Ra's), 2-step self-etch adhesives (2SEa's), 1-step self-etch adhesives (1SEa's), glass-ionomers (GI's) and self-adhesive composites (SAC's). The first four can bond restorative composite to tooth tissue. Both 2SEa and 1SEa were further sub-divided in ‘mild’ and ‘intermediately strong (1/2SEa_m), with a pH ≥ 1.5, and ‘strong’ (1/2SEa_s), with a pH < 1.5. From the restoration retention rates as a function of time the average annual failure rate (AFR) per adhesive and adhesive class was calculated.ResultsThe lowest AFR scores [mean (SD)] were recorded for GI [2.0 (1.4)] shortly followed by 2SEa_m [2.5 (1.5)], 3E&Ra [3.1 (2)] and 1SEa_m [3.6 (4.3)] (Tukey Contrasts: p > 0.05). Significantly higher AFR scores were recorded for 1SEa_s [5.4 (4.8)], 2E&R [5.8 (4.9)], and 2SEa_s [8.4 (7.9)] (p > 0.05). In addition, significant differences in AFR were noticed between adhesives of the same class (Kruskal–Wallis sum test: p > 0.05), except for GI (p = 0.7) and 2SEa_m (p = 0.1). Finally, selective enamel etching did not significantly influence the retention rate of SEa (AFR SEa_etch = 0.43 (0.49), AFR SEa_non-etch = 1.43 (1.77).SignificanceThe adhesive approach significantly influences the clinical effectiveness of adhesives in NCCLs. Within each class, except for GI, there was a wide variation in clinical bonding effectiveness.