Fibre post removal using ultrasonic tips: A comparative in vitro study using different protocols.

This study evaluated the glass fibre post (GFP) removal using three different protocols with ultrasonic tips. Thirty-six extracted single-rooted teeth were endodontically treated and cemented with a 10-mm GFP. Three protocols were used for GFP removal: 20 s activated with cooling, 20 s activated without cooling and 40 s activated without cooling. The removal time and temperature increase on the external root surface were recorded. The amount of residual material and the volume of dentin loss were assessed using micro-computed tomography. Data were analysed using ANOVA with a 5% significance level. The removal time and the amount of residual material were not affected by the protocol. There was no difference in temperature increase between the 20-s groups. The 40s activated without cooling produced the highest temperatures, especially in the apical region, and greater dentin loss. It is not advisable to use the ultrasonic insert continuously for more than 20 s.