Two-year clinical comparison of a microfilled and a hybrid resin based composite in non-carious Class V lesions

The purpose of this double-blind clinical trial was to compare the retentio n rate in noncarious Class V lesions of two resin-based composite restorati ve materials with contrasting stiffness. Isolation with retraction cord, pr essed paper triangles, and cotton rolls was used to closely mimic the proce dures generally used in a practice setting. Thirty pairs of restorations we re placed, one using Silux Plus and one using Z100. The assignment of mater ial was randomized, and the subjects were unaware of the material used, All restorations were placed with a fourth-generation adhesive liner, Scotchbo nd Multi-Purpose. Evaluations were performed at baseline, 6, 12, 18, and 24 months by two independent; examiners using criteria developed by Cvar and Ryge in a forced consensus model. Examiners were unaware of the restoration 's group identity. No difference between the retention rates for the two gr oups was found after 24 months, bringing into question the role that a mate rial's stiffness plays in determining retention in a noncarious Class V les ion.