Evaluation of remaining dentin thickness following use of three different rotary nickel–titanium retreatment files: A cone-beam computed tomography study

AIM: The aim of the study is to measure the amount of remaining dentin thickness (RDT) following retreatment using three different rotary nickel–titanium (NiTi) systems. METHODOLOGY: Mesiobuccal roots of 45 extracted maxillary first molars were prepared up to F(2) ProTaper File and obturated. After cone-beam computed tomography (CBCT) imaging, to evaluate the obturation, the samples were randomly assigned to three retreatment groups (n = 15). Group I was retreated with ProTaper Universal retreatment kit, Group II and III with M(TWO) and D-Race retreatment files, respectively. Postoperatively, all samples were subjected to CBCT imaging and evaluated with AutoCAD software (AutoDesk, Inc.) Mill Valley, California, U.S. to calculate the RDT. Data were statistically analyzed using one-way ANOVA and Tukey's post hoc tests, and the level of significance was set at P = 0.05. RESULTS: The amount of RDT was significantly more in D-Race and M(TWO) groups when compared to ProTaper group. CONCLUSION: D-Race and M(TWO) instruments were associated with significantly more RDT than ProTaper.