神经生长因子对口腔种植体早期骨结合影响的实验研究

目的 观察外源性神经生长因子(nerve growth factor,NGF)对口腔种植体骨愈合的影响,以期缩短口腔种植体骨愈合时间.方法 在12只新西兰大白兔下颌骨双侧各植入种植体1枚,右侧为实验组:种植体边缘骨膜下注射1.0μgNGF;左侧为对照组:同样部位注射相同剂量的生理盐水.注射1次/d,连续7 d.术后2、4、8周分别处死动物各4只,获取下颌骨,制作种植体骨磨片甲苯胺蓝染色标本,行大体、放射学和组织学观察以及骨计量学分析.结果 术后2、4周各组下颌骨种植体周围新生骨密度低于正常骨组织,种植体骨结合率对照组2周(26.67±3.88)%、4周(52.59±5.07)%;实验组2周(42.24±6.67)%、4周(72.25±6.30)%;术后8周两组骨密度与正常骨组织相近,实验组新生骨小梁出现哈弗系统,种植体骨结合率两组相比,差异无统计学意义.结论 口腔种植术后早期加入外源性NGF能够加速种植体周围骨小梁的形成和成熟,增加骨结合面积,提高种植体骨结合率,缩短口腔种植体骨愈合时间.

Effect of nerve growth factor on the early phase of osseointegrafion around oral implants

Objective To observe the early bone integration of oral implants after injection of exogenous nerve growth factor(NGF) and investigate the effects of NGF on peri-implant osseointegration.Methods Twelve New Zealand white rabbits were used in this study to establish bi-mandible implant model. Then local injection of 1 μg NGF was given on the right side of the mandible as experimental group and normal saline only was injected on the left side as control group once a day for seven days. The rabbits were respectively sacrificed at 2,4 and 8 weeks after surgery. The implant-bone grinding samples were prepared and stained by toluidine blue for general observation, X-ray, histology and bone histomorphometry analysis. Results The density of the new bone around implants at 2 and 4 weeks was lower than normal bone. Compared with the control group, the quantity of new bone and bone-implant contact ratio significantly increased in the experimental group. At 8 weeks, the new bone density in both groups was similar to the normal bone. In the experimental group, the haversian system was observed. Bone contact ratio was significantly different between experimental and control group at 2 and 4 weeks, but similar at 8 weeks.[ control group at 2 weeks (26. 67 ± 3. 88) %,4 weeks (52. 59 ± 5.07 ) % and 8 weeks (97. 33 ± 6. 75 ) %,experimental group at 2 weeks (42. 24 ± 6. 67 ) %, 4 weeks ( 72. 25 ± 6. 30) % and 8 weeks ( 99. 15 ±4. 68) % ]. Conclusions Applying exogenous NGF in the early phase could accelerate the formation and maturation of trabecular bone around the implants and shorten the period of osseointegration. Nerve growth factor could promote osseointegration in the early stage of oral implantation.