锶磷灰石烧结体修复颌骨缺损的实验研究

目的　用不同比例的元素锶 (Sr)替代羟磷灰石 (HA)中的部分钙元素 ,通过动物实验研究该种复合人工骨在颌骨缺损修复中的应用。方法　将 32只新西兰大白兔 (简称新白 )分为 4组 ,在兔的下颌角造成约 2 m m×12 mm× 4mm的缺损 ,用不同浓度 (10 % ,5 % ,0 % )的含锶 HA块分别予以修复 ,于 2周 ,1月 ,3月 ,6月时随机处死一组进行尸解、组织学、扫描电镜观察以评价其骨修复能力。结果　掺锶羟基磷灰石复合人工骨几乎不引起排斥反应 ,术后早期即随材料的降解 ,新生骨引导进入降解间隙 ,并逐渐诱导未分化细胞转化为成骨细胞 ,随时间延长其成骨量明显较纯羟基磷灰石组为多 ,同时发现 5 %的锶磷灰石烧结体其成骨能力较 10 %者好。结论　掺锶羟基磷灰石较纯羟基磷灰石有更好的组织相容性、骨引导能力及生物降解率 ,并可能具备一定程度的骨诱导能力 ;掺锶羟基磷灰石的骨形成能力与其浓度并不成正相关。

THE EXPERIMENTAL STUDY OF Sr-HAP ON REHABILITATING MANDIBULAR BONE DEFECT

Objective Element Strontium of different ration was added to Hydroxyalapatite by altering element Ca in order to study the application of rehabilitation of mandibular bone defect through animal experiment. Method 32 rabbits were divided into 4 groups for detailed study. Bone defects with size of 6mm×12mm×4mm were made at the mandibular angles of rabbits and Sr HAP with different proportion (10%, 5%, 0%) was applied to reform the bone defect. One animal group which was randomly selected was killed separately at 2 weeks, 1 month, 3 months, 6 months to evaluate the capacity of bone rehabilitation with methods as anatomy observation, histology analysis and SEM (Scanning Electron Microscope). Results Sr HAP almost hadn't been rejected by host bone, and early after operation the new bone was induced to the porous materials space with the degradation of Sr HAP, and gradualy the undegraded stem cell was transfered to mature osteoplast. The total osteoplastic capacity of Sr hap is higher than that of pure Hydroxyapatite during the whole period, at the same time we also found 5% Sr HAP had a better bone reconstruction capability than 10% Sr HAP. Conclusion Sr HAP has a better biocompatibility and biodegradation than pure HA and has an excellent osteoinductivity. The osteoplastic ability of Sr HAP has no positive relationship with proportion of Strontium increasing in the materials.