Comparison of Three Different Nickel-Titanium Endodontic Rotary Systems in Shaping Simulated S-Shaped Canals
Date of Award
Master of Science (MS)
Stover, Sheila E.
Hashimoto, Lance K.
Introduction: Preparation error may result during mechanical instrumentation because of the complex anatomy of the root canal. Thus, flexibility and resistance to fracture are ideal properties that endodontic instruments should have. The aim of the study was to compare the shaping ability of three different nickel-titanium rotary instruments in simulated S-shape root canals by measuring transportation and canal volume change CVC. Materials and Methods: A total of 60 S-shaped canals in resin blocks were randomly allocated into 3 groups (n=20): Vortex Blue (Dentsply-Tulsa Dental Specialties), HyFlex CM (Coltène/Whaledent) and EndoSequence (Brasseler USA). Canals were filled with dye and secured in a jig for instrumentation stabilization and imaging standardization. After patency was confirmed using a size 10 K-file, groups were instrumented using a crown down technique from size 40 to 20/.04 and then apically enlarged to size 30/.04 using constant sterile water as an irrigant. Pre- and post instrumentation images were taken and layered for evaluation. Transportation and the CVC at the cervical, middle, and apical levels were measured/computed. Data obtained were statistically analyzed using a one-way ANOVA test and Tukey post hoc test. Results: Instrumentation with HyFlex CM resulted in significantly (p<0.05) less canal volume enlargement overall and at all levels compared to the other two files. No significant differences (p>0.05) were observed between the files for apical transportation. Conclusion: HyFlex CM showed better shaping ability than Vortex Blue and Endosequence but similar apical transportation.