Microleakage and damage to adjacent teeth when finishing Class II adhesive preparations using either a sonic device or bur.

Purpose: To detetmine the damage to adjacent tooth surfaces and the quality of the marginal seal of a resin-based composite restoration when a sonic preparation device (Sonicsys) was used to finish the preparation outline.

Materials And Methods: Three general practitioners prepared 60 Class II box-type cavities in extracted teeth placed in an artificial jaw in a phantom-head. In 30 preparations a bevel was made with a bur, in the other 30 restorations the margins were finished using the sonic preparation device.