Objective: To evaluate the survival rate, success rate, soft tissue conditions and marginal bone level changes of implants following micro crestal flap-alveolar ridge preservation at molar extraction sockets with severe periodontitis, compared to natural healing. Methods: From March 2015 to January 2017, patients scheduled for molar extraction as a consequence of severe periodontitis and planned implant-retained prostheses from Department of Periodontology Peking University School and Hospital of Stomatology were selected. A total of 40 molar extraction sockets from 40 patients received implant placement following micro crestal flap-alveolar ridge preservation or natural healing. The front consecutive 20 teeth were assigned to the natural healing group, and the back ones were assigned to the micro crestal flap-alveolar ridge preservation (MCF-ARP) group. The superstructures were placed 6 months later. Within 2 weeks (baseline) and 1, 2 and 3 years after implant crown restoration, modified plaque index, probing depth, modified bleeding index and keratinized tissue width were recorded every six months. Parallel periapical radiographs were taken to evaluate the peri-implant marginal bone level and to calculate marginal bone loss. Independent sample t test or Mann-Whitney U test were used to compare the differences in the above clinical and imaging indicators between the two groups. Results: The implant survival rate and success rate of the two groups were both 100% (20/20). There were no significant differences in the modified plaque index, probing depth, modified bleeding index, buccal keratinized tissue width and marginal bone loss between two groups at 1, 2 and 3 years after implant crown restoration (all P>0.05). Marginal bone loss was 0.22 (0.14, 0.34) mm in the natural healing group and 0.21 (0.12, 0.30) mm in the MCF-ARP group at a 3-year post-loading evaluation. Conclusions: Within the limitations of the present study, implants placed at ridge preserved and naturally healed molar extraction sockets with severe periodontitis demonstrate comparable clinical outcomes at a 3-year post-loading evaluation.
目的： 评价重度牙周炎磨牙拔牙微翻瓣牙槽嵴保存与自然愈合后实施种植修复3年种植体存留率、成功率、种植体周软组织情况以及边缘骨水平变化。 方法： 纳入2015年3月至2017年1月就诊于北京大学口腔医学院·口腔医院牙周科，因重度牙周病变需要拔除磨牙并拟进行种植修复的40例重度牙周炎患者，共计40颗磨牙，根据就诊时间，前20颗磨牙纳入自然愈合组，后20颗磨牙纳入微翻瓣牙槽嵴保存组，两组患者分别在拔牙后自然愈合或经过微翻瓣牙槽嵴保存后进行种植治疗，6个月后两组患者均接受上部结构修复。所有患者在种植冠修复完成2周内（基线）、修复后1、2、3年复查记录种植体改良菌斑指数、探诊深度、改良出血指数和颊侧角化组织宽度；拍摄平行投照根尖片，测量种植体边缘骨水平，计算边缘骨丧失量。采用独立样本t检验或Mann-Whitney U检验比较两组间上述临床指标和影像学指标的差异。 结果： 两组种植体负重后3年存留率和成功率均为100%（20/20）。两组种植体改良菌斑指数、探诊深度、改良出血指数、颊侧角化组织宽度和边缘骨丧失在修复后1、2、3年差异均无统计学意义（均P>0.05）。自然愈合组负重3年时边缘骨丧失为0.22（0.14，0.34）mm，微翻瓣牙槽嵴保存组负重3年时边缘骨丧失为0.21（0.12，0.30）mm。 结论： 在本临床研究有限的范围内，重度牙周炎磨牙拔牙微翻瓣牙槽嵴保存和自然愈合种植修复后3年种植体的临床效果相当。.