An investigation of bone induction by Growth Differentiation Factor-5/β-TCP complex in the dog frontal sinus and bone formation around the dental implants that were placed in.

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This study assessed the efficacy and technical feasibility of inducing bone formation in adult beagle dogs of maxillary sinus floor augmention using β-tricalciuin phosphate (β-TCP) matrix with a recombinant human growth differentiation factor 5 (rhGDF-5).Project 1: The complex of the β-TCP matrix with rhGDF-5 (rhGDF-5/β-TCP) is made of approximately 300 micro-meter β-TCP particles and rhGDF-5 which contained 500 micro-grain per gram of β-TCP particles. Exposure of the frontal sinus was carried out bilaterally, with one sinus receiving 2 grams of the rhGDF-5/β-TCP implant and the other receiving 2 grams of β-TCP particles alone (control). The frontal sinuses were excised 1, 2, 4, 8, 12, 16, 20 and 24 weeks after surgery, and bone formation in response to the rhGDF-5/β-TCP implant was evaluated histologically. At 4 weeks of post-implantation in the site implanted with rhGDF-5/β-TCP, new cancellous bone and a little interconnected trabecular structure appeared at localized site on the ori … More ginal bone surface. At 8 weeks, bone marrow was found within the sinus of the rhGDF-5/β-TCP implants. Cartilage was not found in any region and residues of carrier β-TCP were seen in the middle area. At the site of the control implants, the bulk of implanted β-TCP particles remained within the sinus. At 12 weeks, the large new trabecular bone extended to the original bone surfaces in the center of the implant site of the rhGDF-5/β-TCP. At 24 weeks, all visible β-TCP particles were embedded in newly formed bone in the site implanted with rhGDF-5/β-TCP. On the contrary, more or less β-TCP particles were found after 24 weeks of healing in the control site.Project 2: The titanium alloy (Ti-6A1-4V) implants were placed in the site with rhGDF-5/β-TCP, which were grafted at 4 weeks after surgery. On each of three follow-up dates, which were 4, 8 and 12 weeks after implant placement surgery, the dogs were sacrificed and bone formations around the implant were evaluated histologically. 8 weeks after the implant placement surgery, newly formed bone was present between the implant threads and connected the implant surface with the original bone and β-TCP particles. In contrast, there was no evidence of bone contact with the implant surface at the control site. At 12 weeks, the bone contact ratio increased and it had surpassed the 8 weeks region. Less