自体牙周膜细胞和釉基质蛋白修复猴下后牙Ⅲ度根分叉病变

Clinical and radiographic evaluation of class Ⅲ furcation defects in the treatment using autogenous periodontal ligament cells with or without enamel matrix derivatives

目的:应用自体牙周膜细胞(periodontal ligament call,PDLC)结合釉基质蛋白(enamel matrix derivative,EMD)植入人工制备的猴Ⅲ度根分叉病损内,探讨此牙周组织工程技术治疗重度根分叉病变的可行性。方法:人工制备3只食蟹猴双侧下颌第二双尖牙、第一磨牙和第二磨牙的慢性Ⅲ度根分叉病损。拔除第一双尖牙,分离牙周膜,取体外培养的第3代PDLC再与牛无机矿化骨胶原块复合培养后植入病损内。3只猴的一侧第二磨牙植入PDLC/牛无机矿化骨胶原块+EMD为A组;对侧同名牙植入牛无机矿化骨胶原块+EMD为B组;一侧第一磨牙植入PDLC/牛无机矿化骨胶原块为C组,对侧同名牙植入牛无机矿化骨胶原块为D组;一侧第二双尖牙置入EMD为E组;对侧同名牙为空白对照组(F组)。所有部位均覆盖胶原膜,每组3颗牙,分别于植入材料前和植入后6个月记录牙颊舌侧根分叉部位的牙周袋探诊深度(periodontal depth,PD)和附着水平(attachment level,AL),拍摄X线片。结果:植入材料后6个月,除少数根分叉暴露的病损外,多数根分叉处的PD和AL有不同程度的改善,依次为E组和F组(第二双尖牙),A组,C组,B组和D组。修复的牙槽骨几乎充满第二双尖牙的根分叉,甚至可见较清晰的骨硬板,其他牙位的牙槽骨虽有一定程度的修复,但在缺损的冠方仍留有较明显的密度减低影。结论:PDLC和EMD均可增加Ⅲ度根分叉病变区牙周组织的修复,两者联合应用效果更好。Ⅲ度根分叉病变的治疗效果不仅取决于植入的细胞和材料,而且受多种因素的影响,尤其是根分叉的大小和牙龈瓣能否很好覆盖病损是影响愈合的重要因素。

Objective ：To evaluate whether the use of periodontal ligament cells（ PDLC ） with or without enamel matrix derivatives （EMD） influences periodontal tissue repair in class Ⅲ furcation defects. Methods： Three adult male Macaea fascicularis monkeys were used. Class Ⅲ furcatiou defects were created at the mandibular second pre-molars, first molars and second molars. The autogenous PDLC were cultured in vitro with Bio Oss Collagen. Six furcation defects in the 3 monkeys were divided as followis, Group A（one second molar） ： PDLC/Bio Oss Collagen ＋ EMD; Group B（another second molar）： Bio Oss Collagen ＋ EMD; Group C（one first molar） ： PDLC/Bio-Oss Collagen; Group D（another first molar） ： Bio Oss Collagen ; Group E （ one second pre-molar） ： EMD ; Group F （ another second pre-molar） ： the empty control. All sites （including buccal and lingual side） were covered with collagen membranes. The monkeys were euthanized at the end of 6 months. The periodontal depth （PD） and clinical attachment level（AL） at the buccal and lingual furcation defects were examined before and 6 months after the implantation. X-rays were also obtained at the same time points. Results： PD and AL were decreased in most sites, the reductions in groups E and F （the second pre-molars） were the most significant, and then in turn were in groups A, C, B and D. The repaired alveolar bones were almost full of furcation area in the second pre-molars, and the relatively clear lamina dura was also found. The alveolar bones in the other sizes only had a little repair, and the obviously low density area still remained in the coronal of the defects. Conclusion： The results of this study indicate that class m furcation defects can not be predictably resolved even with the combination of autogenous PDLC and EMD, although they may increase the repair of periodontal tissue in the area of class Ⅲ furcation defects separately. The sizes of furcation defects and the coverage of gingival flap would influence the outcome of the treatment of class Ⅲ furcation defects.