VEGF和TGF-β_1促进非血管化骨移植同期种植骨结合的实验研究

The effect of VEGF and TGF-β_1 in bone-implant osseointegration in non-vascularized bone graft with implant-an animal study

目的:探讨外源性VEGF和TGF-β1对非血管化骨移植同期种植的影响。方法:选用实验犬24只(术前1个月拔除双侧下颌前磨牙),随机分为A、B 2组。选取左侧下颌骨造成2.5 cm全层骨缺损,植入同样大小的全层自体髂骨,钛板固定(髂骨块离体时间控制在20 min以内)。A组(12只)移植髂骨块内植入1枚钛种植体。B组(12只)将钛种植体与rhVEGF165和rhTGF-β1复合后再同法植入移植髂骨内。在所有实验犬的右侧下颌无牙区植入1枚种植体作为对照。术后1、2、4个月取材,行X线、组织学、显微CT观察和种植体骨结合力测试。结果:术后1、2个月B组种植体骨接触率较A组显著增高;对种植体周围骨小梁的显微CT分析表明,B组的成骨的作用较A组明显增强。术后4个月,A、B 2组BIC达到60%以上,种植体骨界面结合力接近220 N,已形成较好的骨结合。结论:VEGF和TGF-β1对NVBG同期种植体骨结合早期(术后1～2个月)有明显的促进作用。NVBG同期种植体在术后4个月可以进行上部义齿修复。

Objective：To demonstrate the effect of VEGF and TGF-β1 in bone healing and bone-implant osseointegration in non-vascularized bone graft（NVBG） with implant.Methods：Twenty-four native dogs were divided into 2 groups at random and premolars of the animals were removed one month before surgery.In each animal,a 2.5 cm-long-defect was made in left side of the mandible,and repaired with the same sized iliac bone taken from the pars iliaca of itself.A rigid fixation was performed with reconstruction plate and steel-wires（Ex vivo time of the graft was less than 20 minutes）.In group A,one implant was put into the transplanted iliac bone.In group B,the implant was attached with rhVEGF165 and rhTGF-β1 firstly and then was implanted into the grafted bone.Another implant was put into the right side of the mandible as the control.The animals were sacrificed at 1,2,4 months after surgery respectively and the grafts were carefully harvested and examined by clinical observasion,X-ray,histology,M-CT and bone-implant bonding force test.Results：In early healing period after surgery,bone-implant contact（BIC） was significant increased in group B than that in group A.Bone histomorphometry examined by M-CT also showed that the growth rate of new trabecular formation surrounding implants in group B was higher than that in group A.Four months after surgery,60 percent BIC and 220 N＇ bone-implant bonding force were acquired in group A and B.Conclusion：In early healing period of the NVBG with implants,VEGF and TGF-β1 can promote osteogenesis and bone-implant osseointegration.Effective osseointegration of NVBG may be formed 4 months after surgery.