复合羟固醇无机小牛骨块修复犬下颌骨临界骨缺损的组织学研究

Oxysterols coated bovine bone blocks used in critical-sized defects of mandible: a histomorphometric study in dogs

摘要:

目的比较复合羟固醇无机小牛骨块（羟固醇骨块）和无机小牛骨粉在比格犬下颌骨临界骨缺损动物模型早期愈合阶段的成骨效应。方法选取健康雄性比格犬4 只，拔除双侧下颌第3 和第4 前磨牙以及第1磨牙（P3-M1）后，双侧下颌骨各复制2个5 mm×10 mm×10 mm标准化箱型临界骨缺损。4 周愈合期后，按半口对照设计，随机将羟固醇骨块和无机小牛骨粉植入骨缺损。术后4 周处死，切取标本制作石蜡和硬组织切片，行组织学观察及组织形态学测量。结果实验动物愈合良好，羟固醇骨块组及无机小牛骨粉组均见临界骨缺损边缘及骨材料-宿主骨交界处明显的成骨细胞及新骨形成。HE 染色组织形态学测量结果显示羟固醇骨块组和无机小牛骨粉组新生骨面积比分别为（37.22±2.16）%和（34.70±2.66）%，两者比较差异无统计学意义（P >0.05）；羟固醇骨块组成骨细胞数[（31.13±2.85）]与无机小牛骨粉组[（24.88±2.95）]比较，差异有统计学意义（P <0.05）。硬组织切片亚甲基蓝-酸性品红染色组织形态学测量结果显示羟固醇骨块及无机小牛骨粉骨材料新生骨面积相对百分比分别为（20.13±1.32）%和（19.28±0.82）%，骨材料相对存留率分别为（30.80±1.16）%和（29.69±1.12）%，两者比较差异无统计学意义（P >0.05）。结论羟固醇骨块在犬下颌骨临界骨缺损早期骨愈合阶段具有类似于小牛骨粉的成骨效果。由于羟固醇骨块具有良好的空间维持能力，更适合于临床大面积骨缺损的修复。

Abstract:

Objective To compare osteogenic effect of oxysterols coated bovine bone blocks (OBB) and bovine bone particles (BBP) in critical-sized dog mandible defects at the early stage of bone healing. Methods Four Beagle dogs were selected. Following extraction of the third and fourth mandibular premolars as well as the first molar (P3-M1), two standardized box-shaped defects (5×10×10 mm) were created at the alveolar ridge in each quadrant (4 defects per animal, a total of 16). After 4 weeks of healing period, the defects were reshaped and randomly allocated in a split-mouth design to either OBB (8 defects) or BBP (8 defects) group. All animals were euthanized after 4 weeks. The specimens were dehydrated for hematoxylin and eosin staining and non-decalcified sectioning. Results The postoperative healing was good. OBB exhibited abundant osteoblasts and new bone formation in the defect area. Histomorphometrical analysis (HE staining) revealed that the percentage of new bone was (37.22 ±2.16)% in the OBB group and (34.70 ±2.66)% in the BBP group, there was no significant difference between the two groups (P >0.05); and the number of osteoblasts was (31.13 ±2.85) in the OBB group which was significantly larger than (24.88 ±2.95) in the BBP group (P < 0.05). Histomorphometrical analysis (methylene blue-acidic fuchsin staining) revealed that the rate of new bone formation was (20.13 ±1.32)% in the OBB group and (19.28 ±0.82)% in the BBP group,the degradation rate was (30.80 ±1.16)% in the OBB group and (29.69 ±1.12)% in the BBP group, the differences were not statistically significant (P > 0.05). Conclusions OBB have similar osteogenic effect as BBP at the early stage of bone healing. Because OBB have good space maintaining property, they are more suitable for the repair of large bone defects.