Four-year clinical evaluation of two self-etching dentin adhesives of different pH values used to restore non-retentive cervical lesions.

Purpose: To evaluate the clinical performance of two self-etching adhesives of different pH values when used to restore non-retentive cervical lesions.
Methods: 84 paired non-retentive class 5 restorations were originally placed in 21 subjects in need of 2, 4 or 6 restorations in incisors, canines and premolars. The retention of the placed restorations relied on the two adhesives only, which were iBOND NG plus B (iB), now marketed as iBOND Self Etch, and Clearfil SE (CB). Lesions were restored with a micro-hybrid composite (Venus). Following a baseline evaluation, the subjects were recalled and evaluated after 3 months, 1 year, 2 years and 4 years.
Results: At the 4-year evaluation, 17 subjects remained who had originally received 66 restorations (33 of each adhesive). Eight of these 66 restorations had dropped out during the 4 years (4 iB and 4 CB) for different reasons. Two of the drop-outs (one iB and one CB) had fractured in the same patient, leaving a large piece of the composite still bonded to the dentin. Two other drop outs (both material iB) were not available for evaluation because they had been crowned (one after endodontic treatment and one after cusp fracture), while the remaining drop-out iB restoration had debonded. Regarding material CB, except for the fractured and partly retained drop-out restoration, the remaining three drop-outs had debonded. Pair-wise comparison of the evaluated parameters using Fishers Exact Test revealed no statistically significant (P < 0.05) differences between the two materials.