珊瑚羟基磷灰石与β-磷酸三钙用于修复种植体周骨缺损的研究

目的:评价珊瑚羟基磷灰石(CHA)与β-磷酸三钙(β-TCP)对种植体周围骨缺损的修复效果.方法:拔除6只Beagle犬双侧下颌前磨牙和第一磨牙.3个月愈合期后,在每侧下颌骨选择4个拔牙位点常规制备种植窝,然后于其冠方制备宽1～1.25 mm、深5 mm的环形骨缺损,每侧各植入4颗种植体,冠方骨缺损区分别按血凝块充填、植入CHA和β-TCP材料3种方式处理,非埋入式愈合.分别于术后4、12和16周处死动物,收获含种植体的骨组织标本制成硬组织切片,测算新骨与种植体接触的最冠方水平至缺损底部的距离(B-D),缺损区种植体骨结合率(BIC％),缺损区内新生骨面积百分比(NFB％)及未降解骨替代材料的面积百分比(RBS％).结果:术后种植体均未发生松动脱落,种植体周围软组织无炎症.植入4、12周时,3组种植体B-D、BIC％值差异均无统计学意义(P＞0.05);16周时,β-TCP组种植体B-D、BIC％值高于CHA组(P＜0.01).在12、16周时,CHA组的RBS％值高于β-TCP组(P＜0.01);16周时,β-TCP组的NFB％值高于CHA组(P＜0.01).结论:β-TCP较CHA能促进种植体周围骨缺损区的骨再生,β-TCP应用于种植体周围骨缺损的修复更具优势.

An Experimental Study on the Restorative Effect of Coralline Hydroxyapatite versus Beta-Tricalcium Phosphate Filled the Bone Defects around Implants

Objective: To investigate the restorative effect of coralline hydroxyapatite (CHA) and beta-tricalcium phosphate (β-TCP) on the defect healing around implants. Methods: All mandibular premolars and 1st molars were extracted bilaterally in six Beagle dogs. After three months of healing, four experimental canals were prepared on each side of the mandible. The margin of the canal was further drilled to create the 1-1.25 mm circumferential and 5 mm deep bone defect around the coronal portion. Then, four implants were inserted in extraction sites on each side. The standardized bone defects were filled with blood clot, CHA or β-TCP,respectively. All implants were non-submerged. Two dogs were sacrificed at 4 weeks, 12 weeks and 16 weeks following implant placement, and the specimens were prepared and stained with trinitrophenol fuchsin for histological and histomorphometric analyses to acquire the data about the distance between the most coronal level of bone-to-implant contact and the bottom of the surgically created bone defect (B-D), and the data about the bone-to-implant contact (BIC%) within the defect area. Values for newly formed bone area percentage (NFB %) and remaining bone substitutes percentage (RBS%) were additionally calculated for all biomaterial-grafted samples utilizing the Image-Pro Plus 6.0 software. Results: No implant was loose or lost after installation. The peri-implant soft tissue was indicated no inflammation. There were no significant differences in B-D and BIC% 4 weeks and 12 weeks after implantation between three treatment groups (P > 0.05). The values of B-D and BIC% were significantly higher in β-TCP group than those of CHA group at 16 weeks (P < 0.01). The value of RBS% was significantly higher in CHA group than that of β-TCP group at week 12 and16 (P < 0.01). The value of NFB% was significantly higher in β-TCP group than that of CHA group at week16 (P < 0.01). Conclusion: The bone regeneration within defects surrounding the implant could be accelerated by using β-TCP than that of CHA, which suggested that the application of β-TCP was one more predictable treatment with respect to restoring bone defects around implants.