Evaluación de la resistencia a la fractura de dientes instrumentados con ProTaper Gold, ProTaper Next y WaveOne Gold

Resumo

Introduction: root canal treatment produces physicist-chemist changes in the dentine and a significant structural loss for the tooth what makes it more susceptible to fracture. Material and methods: 64 mandibular premolar were decoronated and randomly divided into four groups (n=16): control group (CG) non-treated, ProTaper Gold™ (PTG™) instrumented group (25.08), ProTaper Next™ (PTN™) instrumented group (25.06) and WaveOne Gold™ PRIMARY (WOG™) instrumented group (25.07). While shaping, cleaning was done with NaOCl 5,25% using a Monoject™ syringe and after shaping, roots were irrigated with NaOCl, EDTA 17% and NaOCl sonically activated. Root canals were obturated using B&L™ system, embedded into standardized acrylic resin blocks and load with a constant vertical force of 0,02 mm/s until root fracture was produced using a universal testing machine (ME-405/20, Servosis™). Comparisons among groups were analyzed with ANOVA test. Results: There were no statistically significant differences (p> 0.05) between the CG and the groups instrumented with PTN™ and WOG™; neither among PTN™ and WOG™ groups. However, statistically significant differences were obtained between the group instrumented with PTG™ and the rest of the groups being PTG™ group the most susceptible to fracture. Conclusions: PTG™ system was the one that weakened more the roots after the instrumentation in comparison with the WOG™ and PTN™ systems.