目的 通过临床及影像学方法,针对罹患重度牙周病变伴有骨壁缺损的磨牙拔牙即刻植入Bio-Oss?覆盖Bio-Gide?胶原膜,采用翻瓣后冠向复位和微翻瓣胶原蛋白覆盖两种创口封闭方法进行牙槽嵴保存,比较6个月后软、硬组织变化。方法 纳入23名患者共24颗重度牙周炎拔除磨牙,根据纳入时间分为牙槽嵴保存一组(翻瓣后冠向复位)和牙槽嵴保存二组(微翻瓣胶原蛋白覆盖),每组各12颗磨牙。拔牙前及术后6个月测量颊侧角化龈宽度,术后即刻及术后6个月拍摄平行投照根尖片评价牙槽骨高度的变化。术中及术后6个月种植手术时测量牙槽嵴顶中央处骨宽度。结果 牙槽嵴保存一组及牙槽嵴保存二组的颊侧角化龈宽度分别减少了(1.6±1.5) mm (P=0.004)和(0.3±1.6) mm (P>0.05)。术后6个月两组牙槽窝中央牙槽骨高度均显著增加,牙槽嵴保存一组增加了(5.53±4.20) mm,牙槽嵴保存二组增加了(7.70±4.35) mm, 差异无统计学意义(P=0.226)。种植手术时,牙槽嵴保存一组的牙槽嵴顶中央颊舌/腭侧骨宽度为(9.5±2.2) mm,牙槽嵴保存二组为(9.3±1.0) mm,差异无统计学意义。结论 两种牙槽嵴保存方法均有利于达到保持并改善拔牙位点牙槽骨的高度、减少牙槽骨吸收的目的,术后6个月牙槽骨宽度满足种植要求,微翻瓣覆盖胶原蛋白方法有利于保存更多颊侧角化龈。

Objective: To evaluate and to compare dimensional alterations of hard and soft tissues in molar extraction sites with irregular deficiency of bone plates due to advanced periodontitis receiving two different procedures, namely the flapped and flapless techniques with Bio-Gide? membrane covering the Bio-Oss? material for ridge preservation. Methods: Twenty-three patients with 24 infected-molar extraction sites received ridge preservation procedure, the first consecutive 12 sites belonged to the flap group (a full thickness mucoperiosteal flap and primary soft tissue closure) and the following 12 sites belonged to the flapless group (minimal flap with a collagen sponge and a secondary soft tissue closure). Width of keratinized tissue was evaluated before tooth extraction and after 6-month healing. Parallel periapical radiographs were taken immediately and 6 months after extraction to evaluate vertical bone changes. The width of the ridge was measured in the center of the ridge at the time of tooth extraction and after 6 months at implant placement. Results: After 6 months, width of keratinized tissue decreased (1.6±1.5) mm in the flap group (P=0.004) when compared with (0.3±1.6) mm in the flapless group (P>0.05). Both groups showed increases in ridge height from the central aspect, (5.53±4.20) mm for flap group and (7.70±4.35) mm for flapless group. These differences between the groups were not statistically significant (P=0.226). The ridge widths were (9.5±2.2) mm for flap group and (9.3±1.0) mm for flapless group at the time of implant insertion, and no statistical significance was observed between the flap and flapless groups. Conclusion: The study points out that both ridge preservation techniques were effective in increasing ridge height and minimizing ridge resorption after tooth extraction, and the ridge width allowed the placement of implants 6 months after ridge preservation. The flapless technique gave positive outcome in terms of the keratinized gingival width than that of the flap technique.