Efficacy of ultrasonic cleaning.

Resin blocks containing simulated root canal spaces were compared with extracted teeth as models for measuring the efficiency of endodontic debridement with hand instrumentation, ultrasonication, or a combination of both techniques. Canal spaces were filled with radioisotope-laden gelatin, and the loss of radioactivity was measured after treatment. No significant differences in efficiency of debridement were observed in teeth prepared with hand instruments or ultrasonics alone; both techniques reduced radioactivity by between 77% and 79%. Ultrasonication after hand instrumentation was the most efficient method; it reduced radioactivity in the teeth and blocks by 88% and 92%, respectively.