Lu Yaqian, Liu Yawen, Xiong Yuhua, Geng Nan, He Feng, Sun Chao, Li Jin, Gu Yongchun
Jiangsu Key Laboratory of Oral Disease, Department of Endodontics, Nanjing Medical University, the Affiliated Stomatological Hospital of Nanjing Medical University, 136 Hanzhong Road, Nanjing, 210029, People's Republic of China.
Sunshine Dental Haishu Clinic, 8 Lengjing Street, Ningbo, 315000, People's Republic of China.
Odontology. 2021 Jan;109(1):231-238. doi: 10.1007/s10266-020-00525-9. Epub 2020 May 20.
The aim of this study was to establish an effective method of locating and negotiating the lingual canal in mandibular first premolars with two canals during root canal preparation. A total of 125 mandibular first premolars with radicular grooves were collected, and after micro-computed tomography scanning, 50 mandibular first premolars with a Vertucci V/III canal form were selected based on the inclusion criteria. Access cavities were prepared, and the lingual canals (LCs) were searched in four following steps: step 1 direct vision and a straight K-file; step 2 stereomicroscopy and a straight K-file; step 3 stereomicroscopy and a pre-curved K-file; and step 4 a long-neck bur. After localization, the LCs were instrumented. In most cases, access to the LC was achieved by step 2 (19/50, 38%) or step 3 (22/50, 44%). In three cases (6%), step 1 alone was enough to achieve access to the orifice, and in six cases (12%), access to the lingual canal was not achieved until step 4. Overall, 43 of the 50 mandibular first premolars (86%) were successfully instrumented, and the remaining seven failed. Two cases failed in the process of negotiating the canal to full length and five cases failed due to procedural errors (ledge formation, canal perforation, vertical fracture, or instrument separation). The LC in mandibular first premolars is a major endodontic challenge. A stereomicroscope and a pre-curved K file are suggested to be valuable tools for detecting and accessing the extra LC.
本研究的目的是建立一种在根管预备过程中定位和疏通下颌第一前磨牙双根管舌侧根管的有效方法。共收集了125颗有根面沟的下颌第一前磨牙，经显微计算机断层扫描后，根据纳入标准选择了50颗呈Vertucci V/III型根管形态的下颌第一前磨牙。制备开髓洞形，并按以下四个步骤寻找舌侧根管（LC）：步骤1：直视下使用直K锉；步骤2：体视显微镜下使用直K锉；步骤3：体视显微镜下使用预弯K锉；步骤4：使用长颈钻。定位后，对舌侧根管进行预备。在大多数情况下，通过步骤2（19/50，38%）或步骤3（22/50，44%）可进入舌侧根管。在3例（6%）中，仅步骤1就足以进入根管口，在6例（12%）中，直到步骤4才进入舌侧根管。总体而言，50颗下颌第一前磨牙中有43颗（86%）成功完成根管预备，其余7颗失败。2例在根管疏通至全长的过程中失败，5例因操作失误（台阶形成、根管穿孔、垂直根折或器械分离）而失败。下颌第一前磨牙的舌侧根管是牙髓治疗中的一个主要挑战。体视显微镜和预弯K锉被认为是检测和进入额外舌侧根管的有价值工具。
