Conventional versus resin based filling material: an in vitro evaluation of time effectiveness of teeth retreated with rotary and hand instruments

Introduction: To compare the amount of time required by rotary NiTi instruments and hand instruments in removing gutta-percha and resilon from root canal during retreatment. Materials and Methods: Sixty human mandibular premolar teeth with straight root canals were prepared. Half of the teeth were laterally condensed with gutta percha and the other half with resilon. Each half was further divided into two groups with one of them retreated with hand hedstrom files and other one retreated with rotary protaper retreatment files. Retreatment time was calculated using a stopwatch. Results: Rotary protaper retreatment files required significantly less time than hand hedstrom files in removing both gutta percha and resilon. Resilon was removed faster than gutta percha. Conclusion: Rotary files were significantly faster in retreatment than the hand files. Also resilon showed better efficacy for instrumentation time during retreatment.