The Experimental Study Of The Influence On Absorption Of Dog's Alveolar Bone Following Tooth Extraction Using Immediate Implantation And Bio-oss As Space Filler Combined With Pure Titanium Membranes

Objects: Study on the feasibility of using immediate implantation and Bio-oss as space filler combined with pure titanium membranes to prevent the absorption of alveolar bone and supply experiment foundation for clinical treatment.Materials and Methods:After the general anesthesia, extract the second and third premolars on bilateral mandible, randomly select three in four tooth sockets, one for immediate implantation(A group),one for filling Bio-oss(B group),one as control(C group).Knock small titanium screw in each group's at buccal alveolar plate of tooth socket as sentinel sign, measure each height and width of alveolar and record. Cover the alveolar of A and B group with titanium membranes, fix four point with small titanium screw and suture contralateral gums tightly. Dogs are sacrificed after 5 months, by means of gross inspection,measure each height and width of alveolar,imaging examination,histological examination,scan energy spectrum analysis to analysis.Result:1,Gross inspection and membranes: there are 4 samples mucosa dehiscence, but only one's titanium membranes loosing, the other three osteogenesis effects are ideal. 2,Ridge height resorption: A group 0.27±0.07㎜ ,B group0.49±0.07㎜ , C group1.40±0.15㎜ , there are significant differences between A and C(P﹤0.05) , there are significant differences between B and C(P﹤0.05), there are no significant differences between A and B (P﹥0.05). Ridge width resorption: A group 0.24±0.13 ㎜ ,B group0.21±0.10㎜ , C group1.19±0.51㎜ , there are significant differences between A and C (P﹤0.05), there are significant differences between B and C(P﹤0.05), there are no significant differences between A and B (P﹥0.05). 3,Imaging examination: implants contact with bone closely, there is no gap between them. The grey scale value of B and C group is 73.04±7.05,45.10±4.71 respectively, there are significant differences between B,C group(P﹤0.05). 4,Histological examination: A group there is lamellar bone around implant, implants contact with bone closely, there is no fibrous tissue;B group : there are partial degradation of Bio-oss particles, a great deal of woven bone on the periphery of Bio-oss, we can observe a row of osteoblast on the surface of neonatal bone. C group's bone trabeculars are arrange sparsely, and tenuously, the square of medullary cavity is larger than B group's. 5,Scan energy spectrum analysis: calcium-phosphorus ratio of dog's normal mandible is 2.63, calcium-phosphorus ratio of A is 2.01±0.12,B is 1.98±0.14, C is 1.53±0.22, there are significant differences between the three groups and normal mandible(P﹤0.05), there are no significant differences between A and B group(P﹥0.05).Conclusion:1.Immediate implantation combined with pure titanium membranes can prevent ridge resorption, pure titanium membranes can promote osteogenesis around cervical part of implant.2. Bio-oss as space filler following tooth extraction combined with pure titanium membranes can prevent ridge resorption and guided bone tissue regeneration.3.There are no significant differences between this two methods in short term.4.The use of pure titanium membranes easily cause mucosa dehiscence, immediate implantation either, so designing of immediate implantation combined with pure titanium membranes should be cautious.