A comparative evaluation of remaining dentin thickness following biomechanical preparation of teeth using different rotary file systems: An in vitro study

AIM: The aim of the study is to compare and evaluate the remaining dentin thickness following biomechanical preparation of teeth using different rotary file systems. MATERIALS AND METHODOLOGY: Sixty noncarious mandibular premolar teeth were collected and decoronated at the level of cementoenamel junction with a diamond disc. All specimens were randomly divided into 5 experimental groups – ProTaper Next (Dentsply Mallifer), Mtwo (VDW, Antaeus, Munich, Germany), RaCe (FKG, La Chaux-de-Fonds, Switzerland), Hyflex electro-discharge machining (EDM) (Coltene-Whaledent, Allstetten, Switzerland), NeoNiTi (Neolix, France) and 1 control group of 10 teeth each. After mounting the samples on a modeling wax sheet, preoperative cone-beam computed tomography (CBCT) scans were taken. Biomechanical preparation of canals was done following the assigned protocol of manufacturers. Postoperative CBCT scans were taken and comparison was carried out with preoperative scans. STATISTICAL ANALYSIS USED: Difference among the groups was analyzed by post hoc Turkey and analysis of variance tests. A P < 0.05 was considered statistically significant for all tests. RESULTS: A comparison of preinstrumentation and postinstrumentation CBCT images revealed ProTaper Next group to remove more dentin at 7 mm as opposed to other groups in mesiodistal direction. However, no statistical difference was evident between ProTaper Next, MTwo, Race, Hyflex EDM, NeoNiTi file systems at 3 mm, 5 mm, and 7 mm in buccolingual direction. A statistically nonsignificant difference was evident between MTwo, Race, Hyflex EDM, NeoNiTi file systems at 3 mm, 5 mm, and 7 mm in both mesiodistal and buccolingual direction. CONCLUSION: Race file system performed better and removed lesser dentin in both buccolingual and mesiodistal directions. More dentin was removed at the coronal in mesiodistal direction with the use of ProTaper Next, and significant difference was seen between Protaper Next group and other groups in the study.