| rhBMP-2 is a kind of bone inductive protein, and plays an important role in bone regeneration and reconstruction. At present, rhBMP-2 with high quality can be produced by the method of gene recombinant. The researches on biomechanics, pharmacokinetics and surgical feature of rhBMP-2 provided solid basis for clinical application. In recent years there are several reports of rhBMP-2 applied in dental implantology. However, it is absent of the experiments of alveolar augmentaion using rhBMP-2 and the paticulated cancellous bone graft combined with rhBMP-2. In the first part of this study, rhBMP-2 was combined with sodium hyaluronate(SA) and rhBMP-2/SA compound is implanted to the cortical surface of tibia of New Zealand rabbits. The new bone induced by rhBMP-2 was observed through histological section, scanning electric microscope(SEM), and the change of element Ca, P, S contained in the new bone was analyzed through energy dispersive X-ray spectrum(EDX). We discussed the process and mechanism of new bone formation induced by rhBMP-2 for providing a new treatment for alveolar atrophy. In the second part of this study, particulated cancellous bone(PCB) was combined with rhBMP-2/SA compound and was grafted to the tibial defect of New Zealand rabbits, and simultaneously titanium implants were placed into the bone defect. We analyzed the results of hematoxiline-eosin stained section, SEM observation and EDX, and discussed the possibility of PCB/rhBMP-2 grafting and simultaneously dental implant placement.Part I : The experimental research on subperiosteal osteogenesis induced by rhBMP-2-1% sodium hyaluronate compoundMaterials and methods: rhBMP-2 is combined with 1% sodiumhyaluronate(SA), and 1ml SA contained 2.5mg rhBMP-2. Each 0.2 ml of this compound was implanted to the cortical surface of one tibia of nine New Zealand rabbits as the test group. The contra side of tibia is implanted with SA as negative control group, and the normal tibia was selected as positive control. Each group of three rabbits were sacrificed at the intervals of 4,8 and 12 weeks post-implantation and the specimens were made for hematoxiline-eosin stained section, SEM observation and EDX of element Ca, P and S.Results: In the test group, the obvious newly formed bone was observed, and the bone is gradually matured. On the contrary, there was no new bone formed at the control side. After the 12th week post implantation, the newly formed bone is the same as the recipient bone through the histological and SEM observation. The results of EDX showed that the content of element Ca and P of the newly formed bone increased obviously through 4, 8 and 12 weeks(p<0.01), while the contents of element S decreased obviously(p<0.01). after the 12th week, there was no obvious discrepancy of the contents of three elements between the newly formed bone of the test group and the recipient bone (p>0.05).Conclusions: This compound can be used as constructional material for bone defect.Part II The study on osseointegration improved by rhBMP-2 between particulated bone graft and simultaneously placed dental implantMaterials and methods: 12 New Zealand rabbits were randomly divided into 4 groups. Four holes were made in tibia of each animal, and the diameter of each hole was 6 mm. PCB obtained from the iliac bone was mixed with rhBMP-2/SA compound and grafted to the upper two holes of the tibia as the test group, and the remained PCB was grafted to the lower two holes as the control group. Simultaneously, 48 titanium implant, 2mm in diameter, were implanted to the bone holes. After 4, 8, 12 and 16 weeks, one group of rabbits was selected to make the specimens for hematoxiline-eosin stained section, SEM observation and EDX. The contents of element Ca, P and S in each group ofbone-implant interface were analyzed.Results: through the HE stained section and SEM observation, the grafted bone of test group was more mature than that of the control group after the same healing period. After 16 weeks of healing, the grafted bone in the test group had the same s...
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