Abstract: Implant restorations have been widely used in the functional reconstruction of partial edentulous and edentulous arches. Severe alveolar bone resorption destruction is usually found at teeth with severe periodontal diseases that need to be extracted. The root apex of the mandibular second premolar is adjacent to the mental foramen area. Due to its location，the inflammation in the root tip area is easy to spread to the mandibular nerve canal. Once the hopeless tooth was extracted，the implant reconstruction is also difficult and risky. The application of alveolar ridge preservation at the time of tooth extraction can preserve good soft and hard tissue contour of the alveolar ridge and provide favorable conditions for implant therapy. The paper shows the whole process of implant restoration and 2-year follow-up observation of a mandibular second premolar site after using alveolar ridge preservation at the time of tooth extraction，which provides a certain evidence and clinical experience for the treatment plan and management of mandibular second premolars with severe alveolar bone destruction. 

Key words: severe periodontitis, mandibular premolars, ridge preservation, dental implantation

摘要： 种植修复已被广泛应用于牙列缺损或缺失的功能重建。罹患重度牙周病变需要拔除的牙齿常存在广泛的牙槽骨吸收破坏。其中下颌第二前磨牙根尖毗邻颏孔区，由于其位置特点使得该处根尖区炎症进展易波及下颌管，一旦保留无望的牙拔除后，其种植修复治疗亦存在较大难度与风险。在拔牙同期应用牙槽嵴保存术可恢复和维持良好的牙槽嵴软硬组织轮廓，为种植治疗提供有利条件。文章完整展示了1例下颌第二前磨牙拔除同期行微翻瓣牙槽嵴保存术，术后进行种植修复及2年随访观察的全过程，为存在严重牙槽骨破坏的下颌第二前磨牙的治疗方案设计与临床处置提供了一定参考。

关键词: 重度牙周炎, 下颌前磨牙, 牙槽嵴保存, 牙种植