| Objective To evaluate the effect of osseointegration due to using PRP in combination withβ-tricalcium phosphate (β-TCP) in bone defect adjacent to implants in dog mandibular .Methods Adopted Curasam-type PRP Rit twice centrifugation, 6ml was phlebotomized from dog hind limb, centrifuged at 1500r/min for 20min,then blood devided three tier,the bottom was red blood cell,the top level layer was blood serum,the juncture was a lamellar containing blood platelet.Imbibed the top level layer serum and the juncture and red blood infra-junction 1mm to another tube, then centrifuged at 2000r/min for 10 min. Then brown materia appeared at the bottom of tube,which was blood platelet. Imbibed superior part and 0.5ml was remained, joggled it and PRP was formed. Added 0.1ml activating agent into PRP,about 5min later, PRP glue was formed. In each of 6 adult dogs ,4 implants were placed in the inferior border of mandibular body and peri-implant defect was created. On the right side,β-TCP combinated with 0.9%Nacl was placed into bone defect as control group;On the left side,β-TCP combinated with PRP was placed as experimental group. 2 dogs were sacrificed at 4 ,8 and 12 weeks after operation ,respectively. X-ray , bone density surveying, scanning electron microscope(SEM) and histoligical observation were carried out to detect the result of bone regeneration and implant osseointegration.Result At 4,8,12 weeks, X-ray and bone density surveying all showed that the regenerative bone density of experimental group was higher than control group; SEM scanning showed that there was obvious difference between experimental group and control group,experimental group had higher bone-implant contact(BIC);Histoligical observation showed that the amount and maturity of osteoblast in experimental group were much more greater than these in control group,the volum of bone trabecula was larger in experimental group ,the volum of fiber tissue was larger in control group.Conclusion (1) Platelet-rich plasma in combination withβ-TCP can improve bone regeneration in peri-implant defect. PRP can release many kinds of growth factors, which can stimulate the proliferation of osteoblast and preosteoblast, inhibit bone resorption, increase collagen protein synthetical ability, induce neovascularization, offer favourable microenvironment for osteanagenesis and bone metabolism. On account of above-mentioned growth factor and fabric mesh stent and bone marrow stem cell and osteoblast, tri-element of tissue engineer are all ready, after a necessary time, PRP can improve bone regeneration ,as showed in the experimental result. (2) PRP can improve osseointergration. Because PRP can educe different function in different period during osseointergration. In the early process of cell adhesion of the implant surface,PRP can offer certain giant molecule protein, which can form stable protein coating; In the course of cell regeneration and differentiation on the implant surface, PRP play a induction role. (3) PRP can decurtate the time of osseointergration. Due to improving bone regeneration and improving osseointergration, consequently PRP decurtate the time of osseointergration.
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