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

Abstract

This literature review has critically analyzed the published research related to the biomechanical preparation of root canals with three-dimensional analysis using micro-computed tomography (micro-CT). In December 2017, six databases (PubMed, Cochrane, Web of Science, Embase, Scopus, and Science Direct) were accessed using keywords to find articles including the use of the micro-CT analysis in biomechanical root canal preparation. There were 60 full articles that were selected, which were screened and read by two authors. The research that was reviewed and analyzed included root canal anatomy and sample selection, changes in canal shape and untouched canal areas, canal transportation and centering ability, and kinematics (motion). Of the studies selected, 49.18% discussed anatomical characteristics, with 54.1% of these studies describing mesial roots of mandibular molars with moderate curvature. Only 35% used a stratified distribution based on root canal system morphology and quantitative data obtained by micro-CT. The analysis of canal transportation and centering ability showed that transport values in the apical third exceeded the critical limit of 0.3 mm in mesial roots of mandibular molars with moderate curvature, especially in the groups in which a reciprocating system was used. In relation to kinematics, 91.70% of the reviewed studies evaluated continuous rotating instruments, followed by reciprocating rotation (38.33%), vibratory (15%), and the adaptive kinematics, which was in only 8.33%. The reciprocating kinematics was associated with higher canal decentralization and transportation indexes, as well as a greater capacity for dentin removal and debris accumulation. This literature review showed that the anatomy, the type of design and kinematics of instruments, and the experimental design are factors that directly influence the quality of biomechanical preparation of root canals analyzed in a qualitative and quantitative manner by micro-CT.

Transportation assessment in artificial curved canals after instrumentation with Reciproc, Reciproc Blue, and XP‐endo Shaper Systems

“…In the current study, resin blocks were selected in order to take advantage of the great benefit represented by the standardization of the anatomy to be used for all tested instruments. Although micro‐computed tomography imaging is the most accurate way to evaluate the transportation of NiTi files, the superposition is a widely accepted method used to assess the shaping effects of instrumentation in simulated root canals …”

Torsional fatigue strength of reciprocating and rotary pathfinding instruments manufactured from different NiTi alloys

“…In addition, the metal mass volume (mm 3 ) of the 3 mm of instrument tips was measured by Micro-CT. Micro-CT is an accurate technology and has been used to assess the quality of root canal preparation, endodontic obturation, and root canal anatomy. 33 There are no previous studies that have evaluated metal mass volume using this method. The results showed that R-Pilot presented a significantly larger cross-sectional area and metal mass volume than did One G (P<0.05).…”

A new classification of cross-sectional root canal shape changes, a cone-beam computed tomography study

“…The variations in the geometry of the cross-sectional root canal shape before forming and cleaning have a great in uence on the changes that occur during root canal preparation and depend on the preparation methods. The preparation and treatment of the apical third of the root canal and apical foramen has been the subject of numerous studies [3][4][5].…”