Effects of rhBMP-2 with various carriers on bone regeneration in rat calvarial defect / 대한치주과학회지

PURPOSE: Bone morphogenetic protein (BMP) is a potent differentiating agent for cells of the osteoblastic lineage. It has been used in the oral cavity under a variety of indications and with different carriers. However, the optimal carrier for each indication is not known. This study evaluated the bone regenerative effect of rhBMP-2 delivered with different carrier systems. MATERIALS AND METHODS: 8 mm critical-sized rat calvarial defects were used in 60 male Sprague-Dawley rats. The animals were divided into 6 groups containing 10 animals each. Two groups were controls that had no treatment and absorbable collagen membrane only. 4 groups were experimentals that contained rhBMP-2 only and applied with absorbable collagen sponge(Collatape(R)), MBCP(R), Bio-Oss(R) each. The histological and histometric parameters were used to evaluate the defects after 2- or 8-week healing period. The shape and total augmented area were stable in all groups over the healing time. RESULTS: New bone formation was significantly greater in the rhBMP-2 with carrier group than control group. rhBMP-2/ACS was the highest in bone density but gained less new bone area than rhBMP-2/MBCP(R) and rhBMP-2/Bio-Oss(R). The bone density after 8 weeks was greater than that after 2 weeks in all groups. However, rhBMP-2 alone failed to show the statistically significant difference in new bone area and bone density compared to control group. Also MBCP(R) and Bio-Oss(R) particles remained after 8 weeks healing period. CONCLUSION: These results suggest that rhBMP-2 with carrier system is an excellent inductive agent for bone formation and we can use it as the predictable bone tissue engieering technique. Future study will likely focus on the kinetics of BMP release and development of carriers that is ideal for it.

A radiographic evaluation of graft height changes after maxillary sinus augmentation and placement of dental implants / 대한치주과학회지

The edentulous posterior maxilla generally provides a limited amount of bone height because of atrophy of the ridge and pneumatization of the maxillary sinus. Maxillary sinus augmentation is one of the surgical techniques for reconstruction of the severely resorbed posterior maxilla. The purpose of this study was to evaluate the survival rate of implants and the long-term changes of graft height after maxillary sinus augmentation by lateral window approach. From September 1996 to July 2004, maxillary sinus augmentation with mixed grafts of autograft, allograft, xenograft and alloplast were performed on 45 patients and 100 implants were placed. We evaluated the survival rate of implants and the changes of BL(bone length)/IL(implant length) according to time using panoramic radiographs. The survival rate of implants was 91.0% for follow-up period. The mean reduction of graft heights was 0.34mm(3.0%) for 6 months and 1.22mm(10.66%) for 3 years after augmentation. The total mean BL/IL was 1.34+/-0.21 during 5 year observation period after augmentation and decreased slightly over time. The result means that graft materials were stable above the implant apex. BL/ILs of 1 stage procedure were significantly decreased at 1-2 year, 3-4 year after augmentation and no statistically significant changes were observed in those of 2 stage procedure. The graft materials of both procedures were stable above the implant apex. No statistically significant changes of BL/IL were observed in the grafts combined with low amount of autogenous bone or without autogenous bone. The graft materials of both groups were stable above the implant apex. The results indicated that the placement of dental implants with maxillary sinus augmentation showed predictable clinical results and the grafts combined with low amount of autogenous bone or without autogenous bone had long-term resistance to resorption in maxillary sinus.