ASSESSMENT OF THREE HEAT TREATED SINGLE FILE SYSTEMS IN GUTTA-PERCHA REMOVAL USING CONE BEAM COMPUTED TOMOGRAPHY (AN IN VITRO STUDY)

INTRODUCTION: Absolute removal of the defective root filling material and regaining apical patency is the primary factor of endodontic retreatment success. AIM OF THE STUDY: Assessment of the ability of Reciproc R25 (VDW, Munich, Germany), Reciproc blue (VDW, Munich, Germany) and the XP-endo shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland) thermally treated rotary files in removing of the root filling material from oval shaped canals using cone beam computed tomography (CBCT). MATERIALS AND METHODS: Thirty six extracted single canaled human mandibular premolar teeth were prepared chemo-mechanically using Revo-S rotary file system (Micro-Mega, France) and obturated. The teeth were randomly allocated into three groups (n=12 each) depending on files used in retreatment procedure as follow: Group I: Reciproc R25, Group II: Reciproc blue, Group III: XP-endo shaper. Pre and post retreatment scans were done using CBCT to calculate the volume of the remaining gutta percha by using computer software (Osirix lite). Time consumed by each file was recoded until gutta percha was completely removed. RESULTS: All used files were not able to remove the entire root filling material from the canals. No statistically significant differences (P> 0.05) in residual gutta percha were detected between the groups, the percentage of reduction was 88.87 % in (Group Ⅰ ), 92.22 % in (Group Ⅱ ), and 88.60 % in (Group Ⅲ ). The XP-endo shaper required more time with statistically significant difference than the Reciproc groups in gutta percha removal. CONCLUSION: All systems removed the root filling material from oval shaped canals effectively. Both reciproc systems were faster than XP-endo shaper in gutta percha removal.