关键词: 牙周炎, 位点保存, 牙槽骨吸收, 骨再生, 软组织

Abstract: Severe periodontitis causes serious damage to the periodontal tissue，and tooth extraction due to periodontitis leads to further irreversible bone resorption and poor soft tissue contour.  Immediate alveolar ridge preservation after tooth extraction can reduce excessive bone resorption，preserve soft tissue effectively，and create favorable periodontal condition for implant prosthesis，so as to obtain satisfactory functional and esthetic outcome. The objective of this review is to discuss the significance of alveolar ridge preservation after tooth extraction due to periodontitis，the influence of periodontitis on alveolar ridge preservation，the operation points of this technique，the timing for implantation，and the evaluation of treatment outcome.

Key words: periodontitis, alveolar ridge preservation, alveolar bone resorption, bone regeneration, soft tissue