组织工程化骨修复兔下颌骨缺损同期种植体植入的实验研究

目的　观察组织工程化骨修复兔下颌骨缺损同期进行HA/SLA Ti或SLA Ti种植体植入后，种植体与骨床发生骨结合的情况。方法　兔BMSCs复合nHAC及PRP用于修复兔下颌骨颊侧范围为15 mm×15 mm的全层骨缺损，同期分别植入HA/SLA Ti种植体（A组）和SLA Ti种植体（B组）。术后1、3、6个月取材，进行大体标本观察、扫描电镜观察、组织学检查及种植体的推入实验和拉出实验。结果　大体标本观察显示，A组术区逐渐由新生骨组织修复，种植体周围形成较完善的骨结合界面，界面骨成熟；B组术区骨愈合状态佳，但种植体周围仍存在少量纤维组织。扫描电镜结果显示：A组种植体较B组种植体与周围新生骨结合的更紧密。组织学检查的结果显示，A组新生骨与种植体表面直接结合，骨形成较B组种植体表面骨形成提前，B组种植体与新生骨之间存在纤维组织。推入实验和拉出实验结果显示，术后1个月时A、B两组种植体的推入应力和拉出负荷无明显差异，术后3个月后A组种植体的推入应力和拉出负荷明显较B组提高，差异具有统计学意义。结论　修复兔下颌骨缺损的组织工程化骨内同期植入的种植体，可与新生的骨组织形成良好的骨结合，其中HA/SLA Ti种植体的骨结合能力较SLA Ti种植体强，且骨愈合时间也较后者提前。

Experimental studies on tissue engineered bones repairing rabbit mandibular defect with synchronous implant embedding

Objective To investigate osteogenesis and integration of tissue engineered bones repairing rabbit mandibular defect with HA/SLA-Ti and SLA-Ti implants synchronously embedded in them. Methods The tissue engineered bone constructed with rabbit BMSCs, nHAC and PRP was used to repair the full-thickness defect with a size of 15mm×15mm in buccal wall of rabbit mandibular, and HA/SLA-Ti (group A) and SLA-Ti (group B) implants were embedded in them synchronously. After 1, 3, 6 months of operation, specimens were harvested and assessed by means of gross observation, scanning electron microscope observation, histological observation, push-out test and uniaxial pull-out test of implants. Results Visible new bone tissue was formed in bone defect region and fine synostotic interface was formed around implants of group A, but in group B, there were some fibrous tissues between implants and newly formed bone. The results of scanning electron microscope observation showed that new bone was connected with HA/SLA-Ti directly and more tightly in group A than in group B. The results of histological observation showed that bone formation on the surface of HA/SLA-Ti was earlier than that on the surface of SLA-Ti. The results of push-out test and uniaxial pull-out test of implants showed that there was no obvious difference of push in stress force and extract out loading between group A and group B after 1 month of operation. However, after 3 months of operation, compared with group B, push in stress force and extract out loading of implants in group A increased obviously and the difference had statistical significance. Conclusion Dental implants embedded synchronously in tissue engineered bones which were used to repair rabbit mandibular defect could form better synosteosis with newborn bone tissue. The ability of synosteosis of HA/SLA-Ti was better than SLA-Ti, and time of bone healing was shorter than the latter.