The effectiveness of different polymerization protocols for class II composite resin restorations.

Objectives: To investigate the effect of reduced light exposure times on Vickers hardness (VH) of class II composite resin restorations.

Methods: Class II restorations were made in vitro in three 2mm thick increments in a human molar. Two composite resins (Clearfil AP-X; Esthet-X) were polymerized with four light-curing units (Halogen; Astralis 10, LED; The Cure, L.