Comparative Evaluation of Shaping Ability of Different Rotary Nickel Titanium Single File Systems in Root Canals of Mandibular Molars: An In-Vitro Study

ABSTRACT

Background: Cleaning and shaping is a critical aspect of endodontic treatment as it influences the outcome of the subsequent phases of canal irrigation and filling and the success of the treatment itself. The goal of instrumentation is to produce a continuously tapered preparation that maintains the canal anatomy, without any deviation from the original canal curvature, facilitating optimal irrigation, debridement, and placement of local medicaments and permanent root filling, at the same time retaining the integrity of the radicular structures. AIM: The aim of the study was to compare the shaping ability of four different Nickel-Titanium single file systems in mesial roots of mandibular first molars. Methods: Eighty freshly extracted mandibular molars, extracted for periodontal reasons were used for the study A muffle-block was constructed as given by Aviad et al.[59] After sealing the apices with wax, the canals were mounted in the muffleblock using self-cure acrylic resin. After complete polymerization of the resin, the block was removed from the model. The blocks were sectioned horizontally at three sites (coronal, middle and apical) by a thin cutting disk (0.3-mm thick) at two levels one 3 mm from the apex and the other 6 mm from the apex. The disk was mounted on an electric saw (CIRSAW, Confident Dental Equipments Ltd, India) for cutting the blocks. Photographs were taken of all three cross-sections of each tooth using a DSLR Camera (Nikon Digital, Tokyo, Japan) at a fixed position. The sections were reassembled in the muffle. The specimens were randomly divided into the following four groups Group l Prepared using Reciproc rotary files. Group 2 Prepared using WaveOne rotary files. Group 3 Prepared using OneShape rotary files. Group 4 Prepared using F6 SkyTaper rotary files. Results: The results of the present study revealed that the use of Reciproc and WaveOne instruments resulted in significantly better canal centering ability than the use of OneShape instruments and F6 SkyTaper (P < 0.05) Reciproc and WaveOne exhibited less canal transportation than OneShape and F6 SkyTape There were no significant differences in the canal transportation between Reciproc and WaveOne. And also no significant difference between OneShape and F6 SkyTaper. One Shape instruments required significantly less time to prepare the root canals followed by Reciproc, WaveOne and F6 SkyTaper (P < 0.05). Conclusion: Reciproc and WaveOne instruments respected the original canal curvature better than OneShape and F6 SkyTaper files.