The purpose of this study is evaluating about the survival rate and causes of failed implants. In this study, the 371 implants was evaluated for the survival rate and failing factors of implant. The survival rate was 96.5%. The failure rate was 3.5%. The average life time of implants was 50 months. The average age of patients treated was 49 years old. In total 371 cases, 13 cases failed implants were removed. The causes of failing implants were poor oral hygiene, excessive occlusal loading, smoking, and etc. The leading causes of failed implants were improper oral hygiene and excessive occlusal loading. In conclusion, I suggest that the periodic plaque control and occlusal force management can improve the survival rate of implants.

Gingival fibroblasts (GF) are the most abundant cell type in periodontal connective tissues, andhave distinct functional activities in the repair of periodontal tissues and in inflammatory periodontal diseases. Human gingival fibroblasts (hGF) can be used for periodontal tissue engineering. This study examined whether the alkaline phosphatase of hGF is enhanced by recombinant human BMP-4 and/or Anti human BMP-4 antibody. hGF was obtained from the excised gingival tissue of an implant patient undergoing 2nd surgery. The tissue was incubated at 37℃ in 5% CO2 and 95% humidity, and the cultivating media was changed every 2 days. The 2nd passage hGF cells were cultured in a medium containing Dulbecco's modified Eagle medium (DMEM) supplemented with 10% fetal bovine serum and 1 X antibiotic antimycotic solution. The control hGF was cultured for 7 days without rhBMP-4/Anti human BMP-4 antibody. The experimental groups were cultured for 7 with BMP-4 (10 ng/ml) and/or Anti human BMP-4 antibody. This study evaluated the differentiation of hGF to osteoblasts using alkaline phosphatase assay. In the experimental groups, the hGF showed abundant positive ALP staining. Among the experimental groups, the experimental group 3 (mixture of rhBMP-4 (20ng/㎖) and Anti human BMP-4 antibody (50000ng/㎖) showed most abundant positive ALP staining. In the control group, the hGF showed weak positive ALP staining. Overall, these results suggest that the ALP expression of hGF can enhanced by rhBMP-4 or mixture of rhBMP-4/ anti human BMP-4 antibody.