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

Area of Science:

• Endodontics
• Dental Materials Science

Background:

• Glass fibre posts (GFPs) are widely used in endodontic restorations.
• Effective and safe removal of GFPs is crucial for retreatment.
• Ultrasonic devices are commonly employed for post removal.

Purpose of the Study:

• To evaluate the efficacy and safety of different ultrasonic activation protocols for glass fibre post removal.
• To assess the impact of cooling and activation duration on removal time, temperature increase, residual material, and dentin loss.

Main Methods:

• Thirty-six endodontically treated teeth with cemented 10-mm GFPs were used.
• Three ultrasonic removal protocols were tested: 20s with cooling, 20s without cooling, and 40s without cooling.
• Removal time, external root surface temperature, residual material, and dentin loss were measured.
• Micro-computed tomography and ANOVA were used for data analysis.

Main Results:

• No significant differences in removal time or residual material were found between protocols.
• Continuous 40s ultrasonic activation without cooling resulted in the highest root surface temperatures, particularly in the apical region.
• The 40s protocol without cooling also led to significantly greater dentin loss compared to other groups.

Conclusions:

• Ultrasonic activation time for glass fibre post removal should not exceed 20 seconds continuously, especially without cooling.
• Prolonged activation increases the risk of thermal damage and excessive dentin loss.
• Careful consideration of ultrasonic parameters is essential for safe and effective post removal procedures.