Department of Endodontics, Postgraduate Program of Endodontics, Faculty of Health Sciences, Catholic University of Córdoba, Cordoba, Argentina.
Division of Endodontics, Department of Oral Rehabilitation, Faculty of Dentistry, National University of Córdoba, Cordoba, Argentina.
Aust Endod J. 2021 Aug;47(2):122-129. doi: 10.1111/aej.12509. Epub 2021 Mar 17.
Stripping perforation is a possible complication in instrumentation of C-shaped canals. This study evaluated the minimum thickness of the root canal wall in C-shaped teeth after instrumentation. Twelve extracted C-shaped mandibular second molars (four teeth of type I, II and III each) were examined by CBCT (voxel size 90 μm) before and after instrumentation with WOG primary file. Micro-CT scans (voxel size 30 μm) were obtained after instrumentation. Percentage of canal wall area touched by the file and minimum thickness of dentine were measured and compared between CBCT and micro-CT. In type I C-shape canals, less than 10% of the canal wall area was touched by the instrument. In ten teeth, the shortest distance to root surface was from the instrumented area; no perforations occurred. CBCT and micro-CT measurements were in good agreement in ten cases; in two teeth, micro-CT revealed considerably shorter distance to root surface. The two shortest distances were 0.27 and 0.41 mm.
根管预备过程中，C 型根管可能发生侧穿。本研究旨在评估根管器械预备 C 型根管后根管壁的最小厚度。对 12 颗下颌第二磨牙（Ⅰ型、Ⅱ型和Ⅲ型各 4 颗）进行锥形束 CT（体素大小 90μm）扫描，在使用 WOG 主锉预备前后进行检查。使用微 CT（体素大小 30μm）进行扫描。测量根管壁受锉刀触及的面积百分比和牙本质的最小厚度，并比较 CBCT 和微 CT 的测量结果。在Ⅰ型 C 型根管中，不到 10%的根管壁面积被器械触及。在 10 颗牙中，距离根尖表面最近的是器械预备区域，未发生穿孔。在 10 颗牙中，CBCT 和微 CT 的测量结果一致；在另外 2 颗牙中，微 CT 显示距离根尖表面更近，最短距离为 0.27 和 0.41mm。
