Abstract: Distal caries in mandibular second molars associated with impacted mandibular third molars are hidden，often located subgingivally，which may lead to pulpitis or apical periodontitis，and accompanied by distal periodontal pathologies such as distal alveolar bone resorption. During the treatment，mandibular second molars face difficulties in rubber dam isolation，anatomical complexities of root canals，iatrogenic injury，insufficient occluso-gingival distance，and coronal restoration. Choosing appropriate dental，periodontal，and restoration treatment is of great value in preserving mandibular second molars. This article reviews the clinical characteristics，treatment difficulties，and clinical treatment strategies selection of pulpitis or apical periodontitis secondary to distal caries in mandibular second molars due to impacted third molars.

Key words: mandibular second molar, mandibular third molar, C-shaped root canal, micro-endodontic therapy, endocrown

摘要： 下颌第二磨牙常因下颌第三磨牙阻生引发远中邻面龋。远中邻面龋位置隐匿，多位于龈下，可继发牙髓根尖周病，并伴随远中牙槽骨的吸收。治疗过程中，下颌第二磨牙存在橡皮障隔离困难、根管形态复杂、根管治疗难度大且易发生并发症、龈距离短、冠部修复困难等问题。选择恰当的牙体、牙周及冠部治疗方案对保留下颌第二磨牙具有重要价值。文章就阻生齿相关的下颌第二磨牙远中龋继发牙髓根尖周病的临床特点、治疗难度及临床治疗策略做一综述。

关键词: 下颌第二磨牙, 下颌第三磨牙, C形根管, 显微根管治疗, 髓腔固位冠