rhBMP-4 combined with ACS or beta-TCP has a significant potential to induce bone formation in the rat calvaria defect model. Within the selected rhBMP-4 dose range and observation interval, there appeared to be no meaningful differences in bone formation.

Purpose: The aim of this study was to evaluate the factors affecting healing patterns of surgically created circumferential gap defects around implants in dogs. Materials and Methods:In four mongrel dogs, all mandibular premolars were extracted. After 8 weeks of healing periods, implants were submerged. According to the surface treatment, turned surface was designated as a group A and rough surface as a group B. In each dog, surgical defects on the left side were made with a customized tapered step drill and on the right with a customized paralleled drill. Groups were also divided according to the width of the coronal gaps: 1.0mm, 1.5mm, or 2.0mm. The dogs were sacrificed following 8 weeks and the specimens were analyzed histologically and histomorphometrically. Results: During the postoperative period, healing was uneventful and implants were well-maintained. As the size of the coronal gap was increased, the amount of bone-to-implant contact was decreased. The bone healing was greater in rough surface implants compared to the turned ones. About the defect morphology, tapered shape showed much bone healing and direct bone to implant contact even in the smooth surface implants. Conclusion: Healing of the circumferential defect around dental implant is influenced by the implant surface, defect width and the morphology of the defect. When using rough surface implants, circumferential gap defects within 2 mm do not need any kinds of regenerative procedures and the healing appeared to be faster in the tapered defect morphology than the paralleled one. (J Korean Acad Periodontol 2008;38:385-394)

This present study was carried out to find out the effects of calcium aluminate cement(CaO·Al203, CAC), which has been developed with biocompatibility and mechanical properties, in biological environments. Two different particle sizes of CAC - 3.5 µm vs. 212-250 µm which is recommended in periodontal bone grafting procedures – were filled in 8mm calvarial defects in Sprague-Dawley rats. The specimens were examined histologically, especially the bone-cement interface and the response of surrounding tissues. The result of this study shows that when calvarial defects in white rats are filled with 212-250 µm calcium aluminate cement, the materials proved to be bio-compatible in growth and healing on the surrounding tissues. When further researches on direct bone adhesion and bone regeneration ability are fulfilled, CAC is expected to be applied to various fields of periodontology in the future.

This study evaluated periodontal repair and biomaterial reaction following implantation of a newly fabricated calcium aluminate bony cement incorporating LiF-maleic acid on the regeneration of 1-wall intrabony defects in the beagle dogs. The surgical control group received a flap operation only, while the experimental group was treated with calcium aluminate bony cement incorporating LiF-maleic acid. The subjects were sacrificed 12 weeks after surgery and a comparative histologic analysis was done. In the experimental group, the grafted calcium aluminate cement was not absorbed and fibrous connective tissue was epithelized around the particles of the grafted bony cement. Because of certain favorable properties, such as its easy manipulation and its ability to maintain the morphology of the defect site by acting as a scaffold, the newly developed cement is suitable for us as a graft material, and could be used very effectively in alveolar augmentation. However, further study needs to be conducted before it can be used as a bone graft material for periodontal tissue regeneration.