Analysis of heat generation using ultrasonic vibration for post removal.

This study measured the temperature of the root surface and post during the application of ultrasonic vibration to cemented posts to simulate post removal procedure. Root canal therapy was performed on ten extracted maxillary incisors. A stainless steel Parapost was cemented into each prepared post space. Ultrasonic vibration was applied to the post and temperatures were recorded at the coronal post and the cervical root surface. Data were analyzed with ANOVA using the independent variables of (a) time of ultrasonic application (15, 30, 45 and 60 s) and 2) location (post and root surface). Greater temperature increase was observed at the post (52.6 degrees C, SD 11.1; 82.6 degrees C, SD 20.1; 111.0 degrees C, SD 29.1; 125.3 degrees C, SD 33.2) compared to the root surface (9.5 degrees C, SD 4.6; 17.5 degrees C, SD 4.8; 25.4 degrees C, SD 7.3; 32.2 degrees C, SD 8.1) for each time period, P < 0.001. Ultrasonic application to the post for longer than 15 s generates high temperature on the root surface.