This study evaluated the effects of mixture of fibrin-fibronectin sealant system(FFSS) and calcium carbonate(CC) in periodontal intrabony defects. Thirty six sites with two or three wall intrabony defect were used. 14 defects treated with periodontal flap surgery were assigned as the control group. 11 defects treated with CC implantation were designed as experimental group 1 and 11 defects, treated with CC and FFSS implantation as experimental group 2. The control and experimental groups all achieved statistically significant improvements in probing depth and clinical attachment level from the baseline (P<0.01). In mean postsurgery probing depth and gingival recession reduction, there were no statiscally significant differences between the experimental groups and the controls. However, mean postsurgery clinical attachment levels of both experimental groups improved significantly more than that of the controls. As a result, we suggest that mixture of FFSS and CC can be used effectively in intrabony defect as osteoconductive materials.