Untouched canal areas and debris accumulation after root canal preparation with rotary and adaptive systems

Abstract

This study assessed the percentage of untouched canal areas and the amount of debris accumulation after canal preparation with ProTaper Next (PTN) and Twisted File Adaptive (TFA) systems using micro-computed tomographic (micro-CT) imaging. Twenty isthmus-containing mesial roots of mandibular molars were anatomically matched through micro-CT evaluation and randomly assigned to one of the two experimental groups (n = 10), according to the system used for canal preparation: PTN (X1 and X2 files using rotary motion) and TFA (SM1 and SM2 files using adaptive motion). After canal preparation up to ISO size 25, the specimens were then scanned and the matched images of the mesial canals, before and after preparation, were examined from the furcation level to the apex to quantify the untouched surface canal areas and to evaluate the amount of accumulated debris. An independent samples t-test and a Mann-Whitney test were used, respectively, to compare these variables between the groups with a significance level set at 5%. Root canals prepared with either PTN or TFA systems were found to present similar untouched canal surface areas (P = 0.52) and hard-tissue debris accumulation (P = 0.39). Both systems produced a suboptimal and similar mechanical preparation of the mesial canals of mandibular molars and were not able to yield root canals completely free from packed hard-tissue debris.

Arrowhead design ultrasonic tip as a supplementary tool for canal debridement

“…, Lopes et al . ). In addition, the micro‐CT approach was used to standardize the sample selection, ensuring comparability of the experimental groups at the baseline regarding root canal morphology.…”

“…Micro-CT technology was the analytic tool used in this study. This nondestructive method is based on an imaging technology that has been considered the gold-standard experimental model to assess several outcomes of root canal treatment as it allows a longitudinal track of the same specimen at different time points (Paqu e et al 2009, De-Deus et al 2015, 2019b, Azim et al 2016, Leoni et al 2017, Lopes et al 2018). In addition, the micro-CT approach was used to standardize the sample selection, ensuring comparability of the experimental groups at the baseline regarding root canal morphology.…”

Root canal preparation using micro-computed tomography analysis: a literature review

“…Regarding selection of the t ype of canal, Vertucci's classification for the evaluation of the root canal preparation showed the use of the Type I (single canal that extends from the pulp chamber to the apex) for incisors, 62 Type II (two canals that leave the pulp chamber and join near the apex to form a single canal), 43 and Type IV (two distinct and separate canals that extend from the pulp chamber to the apex) in mesial roots of mandibular molars. 12,14,40,44,45,47,97,101,104 Also, in mesial roots of mandibular molars, isthmus classification Type I (narrow sheet and complete connection existing between two canals) 128 or Type III (incomplete isthmus existing above or below a complete isthmus) 57,58 was seen.…”

“…This system was designed to permit switching from a continuous clockwise motion (when the instrument is not subjected to stress within the canal) to an interrupted reciprocation motion (when undue tensions are generated by dentin) during instrumentation. 37,44,45,47,53,54,55,56,57,58 There are also instruments designed with center of mass and/or center of rotation in offset that, in rotation, produce a mechanical wave that runs through the active part of the instrument. This results in improvement of the flexibility along the active part of the instrument and minimizes the instrument locking in the dentin, in addition to reducing the formation of debris.…”

“…27,76,77,78 The development of micro-CT allows a more precise RCS evaluation than a conventional CT scanner, and more recent use of specific software has made it possible to accurately assess the biomechanical preparation as well as the anatomy, root canal filling, and retreatment. 2,3,4,5,7,9,11,12,13,14,15,25,27,28,29,30,31,34,35,37,38,39,40,41,42,43,44,45,47,56,57,58,59,61,62,63,68,79,80,81,82,83,84,85,86,87,88,…”