A Comparative evaluation of the shaping ability, canal straightening, and preparation time of five different NiTi rotary files in simulated canals.

AIM: The aim is to compare the shaping ability, canal straightening, and the preparation time of five different nickel-titanium rotary files in simulated J-shaped canals. MATERIALS AND METHODS: Ninety J-shaped canals in resin blocks were filled with 2% Methylene Blue solution and pre-instrumentation images were taken using a Leica microscope at a ×10. They were prepared until size 25 taper 0.04 using (n = 18 per group): T-Flex, HyFlex CM, Vortex Blue, S5, and iRace. After instrumentation, images were captured again, and composite images were made using Adobe Photoshop imaging software. The differences in canal width and canal curvature at each respective landmark were measured and compared. The preparation time and canal abbreviations were also recorded. Statistical analyses were performed using one-way ANOVA and post hoc Tukey HSD tests. The level of statistical significance was set to P = 0.05. RESULTS: HyFlex CM demonstrated the least difference in canal width after instrumentation, but no significant difference (P > 0.05) as compared to T-Flex and Vortex Blue. The mean canal straightening ranged between 0.91° and 7.65°. T-Flex created the least canal straightening after instrumentation which was significantly less (P < 0.05) than S5, but there was no significant difference (P > 0.05) when compared to HyFlex CM. Instrumentation with the S5 file was significantly faster (P < 0.05), whereas HyFlex CM was the slowest. CONCLUSION: T-Flex, HyFlex CM, and Vortex Blue demonstrated better shaping ability, whilst T-Flex and HyFlex CM maintained the original canal curvatures well. S5 tended to straighten the canals and caused the greatest canal transportation, but it required the least amount of time to shape the canal.

Cone-beam computed tomography diagnosis and nonsurgical endodontic management of a taurodontic mandibular first premolar with two roots and four canals: A rare case report.

Successful root canal treatment requires a thorough understanding of the normal root canal anatomy and possible variations for each tooth. Variations in the root canal anatomy are frequently associated with complex orientations of pulp tissues and complicating mechanical and chemical debridement. Inability to manage such complications may result in endodontic failure. Mandibular first premolars often exhibit a wide range of anatomic variations, complicating clinicians' treatment. This clinical case report discusses the cone-beam computed tomography (CBCT) diagnosis and nonsurgical management of a taurodontic mandibular first premolar with two roots and four canals under a dental operating microscope (DOM). In endodontically challenging cases, using a DOM and CBCT imaging can help the clinician gain a better understanding of the complex root canal anatomy, allowing the clinician to more efficiently explore, clean, shape, and obturate the root canal system.