Comparing instrument retrieval techniques for their efficiency and dentin preservation: A micro-computed tomography study

Aim: The study aimed to compare and evaluate the radicular dentin structure loss while retrieving separated instruments using two instrument retrieval techniques in mandibular molars using micro-computed tomography (micro-CT) analysis. Methods: ProTaper universal file F2 of 5 mm was separated in the middle third of moderately curved mesiobuccal canals of 36 mandibular molars which were then randomly assigned to two groups: Group I – hypodermic surgical needle and file technique and Group II – broken tool removal (BTR) pen. Instruments were retrieved under magnification, and they were assessed for various parameters such as changes in canal volume and remaining dentin thickness using micro-CT before and after retrieval, overall success rate, and time required. Results: The overall success rate of instrument retrieval was 66.7% out of which the BTR pen had a success rate of 77.8%, whereas the hypodermic surgical needle and file technique had 55.6% though at a higher cost. Conclusion: The time taken and success rate for retrieval and differences in axial diameter and volume before and after retrieval in Group II BTR pen were lesser and statistically significant ( P < 0.05) as compared to Group I (hypodermic surgical needle and file technique).