The Influence Of Osseointegration Between Bones And BLB Ⅲ Implant With Different Insertion Torques

Objective: To compare the osseointegration between bones and BLBⅢimplant with different insertion torques in order to find the optimum insertion torque, enhance the success rate and promote the development of domestic implant system.Methods: Select 4 healthy adult beagle dogs as experimental subjects, they are all male. Each dog has four experimental sites (the second and fourth mandibular bilateral premolar). Each site will insert two implants. In accordance with the Latin square experimental design methods, we can determine the insertion torque of each site: 15N·cm(group A),25N·cm(group B),35N·cm(group C)and 45N·cm(group D). 32 implants will be inserted in two times according to the completely randomized experimental method.8 teeth were extracted after anesthesia and then implant immediately(groupⅠ). Another 8 teeth were extracted after anesthesia at the moment of the groupⅠhealing 1 month(groupⅡ).After 2 months 4 dogs were sacrificed and taken out of the mandibular with implants. The samples were analyzed by clinical observation, radiographic observation, fluorescence observation, optical microscope observation and quantitative histological analysis.Results:1. Clinical observation: A total of 32 implants have no postoperative inflammation, percussion sound crisp and no clinical mobility.2. Radiographic observation: GroupⅠhas higher bone density than groupⅡ, there is no gap between them. In groupⅠand groupⅡ, group B and group C have more regular and denser trabecular bones, new bones grow more actively.3. Fluorescence observation:Detect double fluorescence bands'distance and new bone mineralization rate of 8 groups respectively .There are differences between groupⅠand groupⅡ(P<0.05); there are significant differences between group B,C and group A,D(P<0.01).4. Optical Microscope observation: In groupⅡ, we can find little new woven bone and bone marrow tissue in group A and D. BMD of group B and C significantly higher than group A and D.Lamellar bone appears in group B and C. GroupⅠhas more new bones and higher bone density. Mineralized bone matrix can be found in group A and D occasionally. Group B and C have more regular and denser trabecular bones, new bones grow more actively. Bone tissue mature surrounding implant, lamellar bone and harvard's tube structure distribute widespreadly.5. Quantitative histological analysis:Detect BIC and OI of 8 groups respectively.There are significant differences between groupⅠand groupⅡ(P<0. 01); there are significant differences between group B,C and group A,D(P<0.01).6.Immunohistochemical experiment:There are positive cells in cytoplasmic matrix of interface's mesenchymal cells and osteoblasts.Detect average gray level and the number of positive cells at the bone-implant interface of 8 groups respectively.There are significant differences between groupⅠand groupⅡ(P<0. 01); there are significant differences between group B,C and group A,D(P<0.01).Conclusions:1. For BLBⅢ, implant with insertion torque of 25N·cm(group B)and 35N·cm(group C)have better osseointegration.2. Fluorescent tracer technique can be well observed implant - bone interface, it can be used as a method of calculating the rate of new bone mineralization .3. BMP-2 is a valuable biochemical index. Average gray level and the number of positive cells at the bone-implant interface can be detect effectively using BMP-2 in immunohistochemical experiment.