The effects of two ultrasonic instruments on root surfaces.

The Orbison ultrasonic instrument and the Cavitron ultrasonic dental unit were compared for the smoothness of the root surfaces they produced. Twenty teeth were analyzed with the scanning electron microscope and classified as to rough or smooth. Both instruments produced similar degrees of smoothness on the root surfaces with minimal scarring. Application of these instruments to the root surface apical to the epithelial attachment produced residual smearing of some of the collagenous fibrils.