Post-Graduation Program in Dentistry, Faculty of Health Sciences, University of Brasilia (UnB), Campus Universitário Darcy Ribeiro, Asa Norte, Brasília, DF, 70910-900, Brazil.
Department of Dentistry, Faculty of Health Sciences, University of Brasilia (UnB), Campus Universitário Darcy Ribeiro, Asa Norte, Brasília, DF, 70910-900, Brazil.
BMC Oral Health. 2022 Feb 11;22(1):37. doi: 10.1186/s12903-022-02067-8.
The endodontic treatment of calcified root canals in molars is a challenging and time-consuming procedure. Even with the aid of a surgical microscope, the risk of root perforation is high, especially in the furcation area. The purpose of this study is to report the Computer-Aided-Design and Manufacturing (CAD-CAM) workflow, the innovative strategies for the template ideation, and the guided endodontic treatment of a mandibular molar with dystrophic calcification in the mesial root canals.
A 58-year-old female patient, ASA I, was referred to endodontic treatment in the right first mandibular molar for prosthetic reasons. The mesiobuccal and mesiolingual canals appeared obliterated in the radiographic images. The absence of dental crown, tooth inclination, and the limited mouth opening of the region contributed to a poor visual reference of the tooth in the dental arch and the direction of the remaining lumens of the canals. Despite using surgical microscopy, the conventional technique led to the deviation of the mesiobuccal canal towards the furcation area. The obliteration of both mesial root canals was confirmed using the Cone Beam Computer Tomography. The clinical history associated with the tomography diagnosis was compatible with dystrophic calcifications in the pulp canals. The patient was submitted to an intra-oral scanning as well. The Digital Imaging and Communications in Medicine data (DICOM) were segmented. The Standard Tessellation Language (STL) files were processed following the CAD-CAM workflow, aiming to create two different endodontic templates with a new open design concept. The templates with open design allowed direct visualization of the operative field, irrigation, and dentin debris removal. The strategy of the guidance sleeves niche as half-cylinders allowed the drill insertion in a limited mouth opening region.
The digital planning and guided access permitted to overcome the case limitations and then re-establish the glide path following the original anatomy of the root canals. The guided endodontic represents a personalized technique that provides security, reduced risks of root perforation, and a significant decrease of the working time to access obliterated root canals even in the mesial root canal of mandibular molars, a region of limited mouth opening.
磨牙钙化根管的牙髓治疗是一项具有挑战性和耗时的过程。即使借助手术显微镜，根管穿孔的风险也很高，尤其是在分叉区域。本研究旨在报告计算机辅助设计和制造（CAD-CAM）工作流程、模板构思的创新策略以及下颌第一磨牙近中根管有发育性钙化的牙髓治疗。
一位 58 岁女性患者，ASA I 级，因修复原因转诊至右侧下颌第一磨牙进行牙髓治疗。近颊和近舌根管在影像学图像中显示为闭塞。缺失的牙冠、牙齿倾斜和该区域的张口受限导致在牙弓中对牙齿的视觉参考不佳，以及根管的剩余腔道的方向难以确定。尽管使用了手术显微镜，但传统技术导致近颊根管向分叉区域偏离。通过锥形束计算机断层扫描（CBCT）确认了两个近中根管的闭塞。临床病史与 CT 诊断相吻合，提示牙髓管有发育性钙化。患者还接受了口腔内扫描。获取数字成像和通信医学数据（DICOM）并进行分段。按照 CAD-CAM 工作流程处理标准 tessellation language（STL）文件，旨在创建具有新的开放式设计理念的两种不同的牙髓治疗模板。开放式设计的模板允许直接观察手术视野、冲洗和牙本质碎屑去除。作为半圆柱的引导套管凹口策略允许在张口受限的区域插入钻头。
数字化规划和引导通道允许克服病例限制，然后根据根管的原始解剖结构重新建立导丝通道。引导牙髓治疗是一种个性化技术，提供了安全性、降低根管穿孔风险，并显著减少了进入闭塞根管的工作时间，即使在下颌磨牙的近中根管，即张口受限区域也是如此。
