성견의 치주질환 이환 발치와에 이식된 Hydroxyapatite 피개이식체 주위의 신생골 형성에 관한 연구

The purpose of this investigation was to evaluate the effect of the decalcified freeze dried bone (DFDB) and guided tissue regeneration membrane(GTAM) on the new bone formation around the hydroxyapatite coated implant inserted into the periodontally involved extraction socket. Experimental chronic periodontitis was induced by the ligation of orthodontic elastic threads after surgically removed the buccal alveolar bone for creating dehescence defect in the mandibular 3rd, 4th premolars of the mandible of the adult dogs for 12 weeks. HA coated implants were placed immediately after extraction in the blateral 3rd, 4th premolars. 4 types of procedures were performed on the dehescence defects as follows 二 Control : sutured without DFDB and GTAM after placing implant Experimental I •• group which bony defects were filled with DFDB Experimental II group which GTAM was place over bony defects Experimental III : group which bony defects were filled with DFDB and covered with GTAM Thereafter dogs were sacrificed at the 12 weeks and specinrens were prepared for light and fluorescent microscopic evaluation. The results of this study were as follows * 1. In dehescence bone defect, new bone formation was minimal in control group but in other 3 groups considerable amount of new bone formation was observed without connective tissue ingrowth with the amount in descending order being experimental III, experimental II, experimental I.2. In fluorescent microscopic examinations, new bone formation in the dehescence bone defect mostly had taken place at the initial healing stage after implantation with the rate in descending order being experimental II, experimental III, experimental III. 3. Aroud the implant under the dehescence bone defect, osseointegration was observed without inflammation in all experimental groups. 4. In Experimental group II and III, thin connective tissue layer was observed beneath the GTAM. 5. DFDB was not resorbed completely throughout the experimental period. These results indicate that new bone formation in bony defects can be attained by the use of GTAM in immediate implantation. If DFDB is used concurrently with GTAM, new bone formation may be delayed, but adequate width and height of bone formation can be attained. The use of DFDB alone can not result in adequate repair of bony defects.