Comparative Evaluation of Root Canal Centering Ability of ProTaper, Mtwo, WaveOne, and Reciproc Using Cone-beam Computed Tomography: In Vitro Study

Abstract

To compare the centering ability of rotating (ProTaper and Mtwo) and reciprocating (WaveOne and Reciproc) file systems using cone-beam computed tomography (CBCT). Eighty extracted human mandibular molars with curvature within 15-45° were selected and randomly divided into four groups (n = 20): group I (ProTaper), group II (Mtwo), group III (WaveOne), and group IV (Reciproc). The selected teeth were arranged in a template, and pre-instrumentation and post-instrumentation CBCT scans were taken using Kodak Carestream CS 9300 machine. The centering ability was measured in four planes namely, at furcation, 3 mm apical to furcation (coronal), 6 mm apical to furcation (middle), and 3 mm coronal to the apex (apical), wherein dentin thickness was measured from pre- and post-instrumentation CBCT scans and recorded for each canal (mesiobuccal and mesiolingual) separately and statistically analyzed. Mtwo and Reciproc remained better centered followed by WaveOne and least by ProTaper in different-level comparisons. In the mesiodistal dimension (MD) at the 3 mm, 6 mm, and 3 mm apical level, Mtwo and Reciproc showed better centering, meanwhile, in the buccolingual dimension, only in the 3 mm apical level, Mtwo and Reciproc remain better centered. A significant difference was seen between the group and type of canal. Mtwo and Reciproc showed better centered preparation than ProTaper and WaveOne. Significant differences were seen between the groups and types of canal. Root canal instrumentation should maintain the original canal anatomy. The proper enlargement keeping in mind the remaining strength in the tooth structure is essentially decided by how the selected instrument is centered. The alloy used for instrument manufacture and its design (taper, cross-section, and tip) will influence the centered preparation. The type of instrument and the instrumentation techniques should be chosen based on root canal anatomy.