<span lang="EN-IN">Fracture resistance of endodontically treated teeth using three novel nickel-titanium <span lang="EN-IN">file systems

Objective: The present study compared the fracture resistance of mandibular premolars instrumented using ProTaper NEXT, TruNatomy, and Neohybrid nickel-titanium (NiTi) file systems.Methods: In this in vitro study, ۵۶ extracted mandibular premolars were decoronated to obtain standardized root lengths of ۱۶ mm. The samples were divided into four groups (n=۱۴): Group I, no instrumentation (control); Group II, instrumentation with ProTaper NEXT files (Dentsply Maillefer); Group III, instrumentation with TruNatomy files (Dentsply Sirona); and Group IV, instrumentation with Neohybrid files (Orikam Healthcare). Following instrumentation, the samples were obturated using the cold lateral compaction technique with gutta-percha and AH Plus sealer. After one week, a vertical load was applied using a universal testing machine. The maximum load required to cause a root fracture was recorded in Newtons (N). Data were analyzed using one-way ANOVA and Tukey’s post-hoc test at the significance level of P<۰.۰۵.Results: The control group exhibited the highest mean fracture resistance (۷۷۴.۳۱ ± ۱۴۰.۸۲ N), followed by TruNatomy (۷۳۲.۷۸ ± ۱۲۸.۲۴ N), Neohybrid (۶۷۹.۶۵ ± ۱۸۵.۷۸ N), and ProTaper NEXT (۶۰۶.۷۷ ± ۱۴۴.۸۵ N) groups. ANOVA revealed a statistically significant difference among the groups (P=۰.۰۳۱). ProTaper NEXT showed significantly lower fracture resistance than the control group (P<۰.۰۵). The TruNatomy and Neohybrid groups showed no statistically significant differences compared with either the control group or the ProTaper NEXT group (P>۰.۰۵).Conclusions: Within the limitations of this in vitro study, all file systems reduced root fracture resistance; however, only ProTaper NEXT caused a significant reduction compared with the control group.

کلیدواژه ها:

Dental instruments ، endodontically treated teeth ، fracture resistance ، Nickel-Titanium alloy ، Root canal preparation ، Root Canal Therapy