自体牙本质片修复骨缺损的实验研究

Pilot study of autogenous tooth dentin graft to repair bone defect

目的：探讨自体牙本质片修复骨缺损的临床效果。方法：选取18只2．5～3 kg新西兰兔，随机分为3组，拔取自体下切牙，制备成牙本质片，在同侧下颌骨下缘制备骨缺损，用钛钉坚固内固定牙本质片于缺损区。分别在术后1、3、6个月取材进行影像学和组织学检查。结果：术后1、3个月仍可见牙本质片与骨组织存在分界，但6个月时牙本质片完全被骨组织覆盖。放射学检查提示牙本质片与骨组织间的低密度投射影随着植入时间延长而逐渐消失，高密度影逐渐形成。组织学显示牙本质片与骨组织界面血管化，牙本质片逐渐被吸收，新骨形成。结论：坚固内固定的自体牙本质片能作为骨缺损修复材料恢复骨缺损。

Objective：To investigate the feasibility of autogenous dentin block to repair the bone defect. Method：Autogenous grafts from freshly extracted teeth were rigidly fixed to the mandibular defects in eighteen rabbits using titanium screws in order to achieve good primary stability. Every six rabbits were stochastically sacrificed at 1,3 and 6 months after implantation respectively. For all specimens,radiographical and histological measurements were performed. Result：The boundaries of the grafts were distinctly visible in the implanted area during the first and third month. However,the teeth grafts were fully covered by new bone after sixth month. The radiograph demonstrated the progressive change in the bone and grafted tooth interface from radiolucency to radiopacity. Histologically,vascularization led to a temporary fibrous-integration in the graft-bone interface and grafts were gradually resorbed and replaced by new bone. Conclusion：Rigid fixation of auto-genous tooth dentin could serve as a novel approach for bone regeneration and to repair of bone defect.