Retention of microfilled and hybrid resin-based composite in noncarious Class 5 lesions: a double-blind, randomized clinical trial.

This double-blind clinical trial was undertaken to compare the retention rate of restorative materials with contrasting stiffness in noncarious class 5 lesions. All restorations were placed using retraction cord and cotton roll isolation to more closely mimic the general practice setting. Thirty subjects with at least two lesions were recruited to participate in the study. Each subject received one restoration using Silux Plus and one using Z100. The assignment of material was randomized, and the subjects were unaware of which tooth had received which material. All restorations were placed with a fourth-generation adhesive liner, Scotchbond Multi-Purpose. Evaluations were performed at baseline, 6, and 12 months by two independent examiners unaware of the restoration's group identity. The restorations were evaluated using criteria developed by Cvar and Ryge in a forced-consensus model. Despite the fact that the two materials have widely different elastic modulus values, after 12 months no difference between the retention rates for the two groups was found, and both groups of restorations performed very well.