Nerve Growth Factor Compound Strontium Substituted Hydroxyapatite In Immediate Implant Bone Defect Repair In Animal Experiment

Objective To use the growth factor and scaffold materials to build one of the moreideal bone substitute material, immediate implant to the surrounding bone defect repairis currently one of the hotspots, according to a certain proportion of the nerve growthfactor by freeze-drying and strontium apatitelaw composite, while strontium apatitecomplex of nerve growth factor is placed around the bone defect, to improve bonesubstitute material content of the growth factor and the performance of its release, toimprove the biodegradation rate of bone defects surrounding bone substitute materials,betterpromote the area around the bone healing of bone defects and improve bonecontact rate.Methods The six experimental dogs were minimally invasive removal of bilateralmandibular second premolars, three or four, at the same time, immediate implantplacement in all36dogs, which were pre-6pieces. We made the mesio-bone defects inperi-implant and randomly divided them into3groups to give different treatmentmethods, which were the experimental group, the positive control group, and the controlgroup. Nerve growth factor compound strontium substituted hydroxyapatite wasimplanted in the experimental group, implantation of strontium substitutedhydroxyapatite in the positive control group implanted, and nothing in the control group.After4weeks and8weeks, three dogs were randomly killed respectively, observingchanges of the anatomy, micro CT and histomorphology. Results1.The experimental animal has no obvious signs of infection after theoperation, operation site wound healing in good condition, no obvious liquid. Implantin the operation does not loose and fall off.2. some of the indicators like BMD、BV/TV、Tb. N about the experimental group and blank control group, experimentalgroup and positive control group, positive control group and blank control group inoperation after4weeks the difference had statistical significance(P<0.05).BS/BV、Tb.Sp, positive control group and blank control group was higher than that inexperimental group, the difference was statistically significant and groups(P<0.05).The Tb. Th index is not statistically significant. At8weeks after operation,the indicators like BMD、BV/TV、Tb.N、Tb.Th about the experimental group and blankcontrol group, experimental group and positive control group, positive control groupand blank control group in operation after4weeks the difference had statisticalsignificance (P<0.05). BS/BV、Tb.Sp, positive control group and blank control groupwas higher than that in experimental group, the difference was statistically significantand groups (P<0.05).3. At4weeks after operation between the experimental group andthe positive control group, the experimental group and the control group was nosignificant difference between BIC values. With the extension of time of8weeksbetween the experimental group and the positive control group, positive control groupand blank control group BIC values are different,8weeks after operation in group BICthan those in the other two groups, blank control group positive control group is theworst, and there was a statistically significant difference between the3groups.Conclusions1.Nerve growth factor combined with SR HAP is a good material forbone repair, can promote bone formation, bone defects around immediate implantimprove osseointegration.2.Instantly grown in a short period of time to achievesatisfactory bone contact rate.