Abstract: Implant therapy is an ideal restoration option for partial edentulousness. Sufficient amounts of soft and hard tissues are necessary for successful implant therapy. The mandibular molar area is closely related to the mandibular canal，and it is necessary to keep a safe distance to avoid nerve injury during implant therapy. Following extraction of mandibular molars with severe periodontal lesions，inadequate bone mass will greatly increase the difficulty and risk of subsequent implant therapy. Ridge preservation can achieve preservation or augmentation for alveolar ridge，thus creating good soft and hard tissue conditions for implant therapy. This article illustrates a case of the mandibular second molar with the periodontal and endodontic lesions undergoing ridge preservation after extraction and receiving implant treatment 6 months later，which increases the safety of implant therapy，and achieves good therapeutic effect and provides experience for clinical management of such cases. 

Key words: mandibular molars, alveolar ridge preservation, dental implantation, periodontal and endodontic lesions

摘要： 种植治疗作为修复牙列缺损的重要方式，充足的软硬组织条件是种植修复成功的必要条件。下颌磨牙区与下颌管关系紧密，种植治疗时种植体最根方与下颌管间应保持一定的安全距离，避免神经损伤。罹患重度牙周病变的下颌磨牙自然愈合后常常骨量不足，要实现以修复为导向的种植治疗的难度与风险大大增加。牙槽嵴保存术能够阻止或减缓牙槽骨宽度及高度的丧失，为种植治疗创造良好的骨量条件。文章展示了1例因牙周牙髓联合病变保留无望的下颌第二磨牙行微创拔牙同期牙槽嵴保存术后6个月实施种植修复治疗的过程，提高了种植治疗的安全性并取得了良好的治疗效果，积累了针对此类病例的临床经验。

关键词: 下颌磨牙, 牙槽嵴保存术, 牙种植, 牙周牙髓联合病变