异种牙本质修复兔颅骨缺损的实验研究

Experimental Study on Bone Deffect Repair with Heterogeneous Dentin in Rabbits

目的:观察异种牙本质修复兔颅骨骨缺损的疗效,探索其作为骨移植替代材料的有效性。方法:将因正畸原因拔除的人健康前磨牙,制成直径2~3mm的牙本质块。在1%氯己定中浸泡5min。使用12只雄性健康新西兰大白兔,在颅骨各建立4个临界骨缺损,将自体骨、人牙本质随机填入骨缺损区,术后4、8、12周随机处死4只兔子,取出颅骨,通过大体观察、Micro-CT及组织学观察颅骨缺损修复情况,使用Micro-CT分析每个时间点新骨形成面积占骨缺损总面积百分比。结果:所有实验动物伤口愈合良好,未见明显炎症反应。经影像学评估,自体骨比异种牙本质成骨量相似,且差异无统计学意义(P>0.05)。组织学染色示:围绕在移植材料周围,可见新骨形成。结论:异种牙本质能促进和加速骨缺损的修复,有望为促进骨缺损的修复提供一种新思路。

Objective To investigate the effect of repairing skull defect with heterogeneous dentin in rabbits and the possibility as bone graft substitutes.Methods Dentin blocks were prepared from human premolars that were extracted for orthodontic reasons.Dentin was processed into fi ner chips 2-3mm in diameter.The processed dentin was cleaned by socking them in 1%chlorhexidine for 5minutes.Bony defects were created on the heads of 12 male healthy NewZealand White rabbits.Four bony defects were created in each skull and randomly grafted with either human dentin blocks(experimental group)or autogenous bone grafts(control group).Rabbits were sacrifi ced at 4、8 and 12 weeks.The general condition of rabbit was observed after operation,and bone defect repair was evaluated by Micro-CT at 4,8 and 12 weeks.Then the tissue of defect area was harvested for histological staining to observe defect repair.Results All animals survived to the end of experiment,and no incision infection occurred during repair process.Micro-CT demonstrated that the new bone volume were similar in the experimental group and the control group,and the difference was not statistically signifi cant(P>0.05).The observation of histology staining indicated that the surface of the grafted materials were covered with new bone.Conclusion Heterogeneous dentin accelerated bone regeneration and augmentation.These resultes suggested that heterogeneous dentin provided potential as a bone graft resource during the bone healing process.