冷冻自体下颌骨复合髂骨移植延期种植后种植体周围骨密度变化初探

Changes of Bone Mineral Density after Composite Transplantation of Frozen Autogenous Mandible with Delayed Implantation

目的:了解自体冷冻下颌骨复合髂骨移植延期种植后种植体周围骨密度的变化情况。方法:选择16只杂交狗为对象,液氮(-196℃)作为致冷剂,分别在动物双侧下颌骨体部制备骨缺损。左侧缺损行冷冻自体下颌骨骨块的原位再植并结合髂松质骨移植(复合移植组,composite transp lantation group,CTG),右侧缺损行自体髂骨块移植(髂骨移植组,iliac transp lantation group,ITG)。术后观察两类骨移植后的伤口愈合情况及骨新生与骨密度变化,术后3个月分别在两类骨块上植入IMZ(TPS种植体,每侧1枚,种植体植入后3、6、9、12周分别处死4只动物取材,通过标本的骨密度扫描进行种植体周围骨密度评价。结果:ITG种植体周围的骨密度均小于CTG,但随着时间的延长,这种差异逐渐缩小,到种植后12周时,这种差异已不明显。结论:骨密度测量结果提示,延期植入的牙种植体可与冷冻自体复合下颌骨形成良好的骨整合。骨密度值可以作为评价种植体周围骨整合情况的一个指标。

Objective： To study the changes of bone mineral density after composite transplantation of frozen autogenous mandible with delayed implantation. Methods： Operations were performed to create two defects in the bilateral mandible of 16 dogs. The left defect was grafted by composite frozen autogenous mandible （immersed in - 196 ~C liquid nitrogen） and fresh cancellous ilium （composite transplantation group, CTG）. The right defect was grafted by fresh ilium （iliae transplantation group, ITG）. One IMZ TPS dental implant was placed into the graft of each side. After 3, 6, 9 and 12 weeks, 4 animals were sacrificed respectively and the grafts with dental implant were harvested to measure bone mineral density to evaluate the peri - implant bone healing condition. Results ： The bone mineral density of peri - implant grafted with CTG was higher than that of ITG. But with the time prolonging, the difference diminished. After 12 weeks implantation, the difference was not obvious. Conclusion： The results of BMD measurements hint that the implant can form good osseointegration with composite transplantation of frozen autogenous mandible following delayed implantation. The BMD values might be an indieatrix to evaluate the osseointegration of peri - implants.