Removal of fractured posts using ultrasonic vibration: an in vivo study.

The purpose of this study was to determine the effectiveness of ultrasonic vibration in the removal of fractured posts from teeth under true clinical conditions. Thirty patients (16 men and 14 women with a mean age of 51 yr, SD 13.13) had ultrasonic vibration applied to the side of a fractured post fragment after creation of a small gutter around the fragment. A piezoelectric ultrasonic scaler was used to apply the vibration for two 15-s periods and then 30-s periods until the post fragment became loose. There was a significant correlation (r = 0.52, p = 0.003) between the cemented length of post fragment (mean length 3.8 mm, SD 1.39) and the time of ultrasonic vibration application (mean time 2.05 min, SD 1.62), but the correlation between post diameter and ultrasonic time did not reach statistical significance (r = 0.35, p = 0.059). The mean ultrasonic time was approximately 25% of that found in previous studies on post removal from extracted teeth probably because of suboptimal cementation of posts in the clinical situation.