|Budget Amount *help
¥2,400,000 (Direct Cost : ¥2,400,000)
Fiscal Year 1999 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1998 : ¥1,400,000 (Direct Cost : ¥1,400,000)
The objective of this study was to investigate regeneration on peri-implant tissues (bone, connective tissue and epithelium) following installation of fixtures with application of recombinant human bone morphogenetic protein-2 (rhBMP-2).
All mandibular premolars of 6 beagle dogs were extracted. After 3 month of healing, apical 5 mm of 10 mm fixtures (Bronemark System【encircledR】, length : 10 mm, diameter : 3.75 mm) were installed in bilateral edentulous bone ridges. RhBMP-2(0.4 mg/ml) with polylactic acid polyglycolic acid copolymer / gelatin sponge (PGS) was applied to cover the coronal half of the fixture in the experimental side. In the opposite side of the mandible, the coronal half of the fixture was covered with PGS alone. RhBMP-2 and PGS were supplied by Yamanouchi Pharmaceutical Co., Ltd.. Three months after installation, the dog was sacrificed. Immediately, the implant regions were dissected and fixed. Undecalcified sections were prepared. Radiographs were taken every two weeks.
Postoperative swelling was observed in the experimental group. Radiographs after 3 months revealed that a large amount of bony tissue regenerated in the experimental group, while the bone height in the control group was almost the same as compared to pre-surgery.
In the experimental group, bone regeneration was significantly greater than in the control group (p<0.01, paired t-test). Furthermore, the epithelial downgrowth in the experimental group was inhibited significantly as compared with the control group (p<0.01, paired t-test).
The results of this experiment suggest that recombinant human bone morphogenetic protein-2 (rhBMP-2) may enhance tissue regeneration on peri-implant tissue around the fixture.