Effects of enamel matrix derivative on bioactive glass in rat calvarium defects

Tissue engineering-based bone grafting has emerged as a viable alternative to biologic and synthetic grafts. The purpose of this study was to evaluate the effect of enamel matrix derivative (EMD; Emdogain gel, Biora AB, Malmö, Sweden) on bioactive glass in enhancing bone formation in rat calvarium defects. Twenty rats were used in the study. In all animals, 2 standardized critical-sized calvarial defects (5.0 mm diameter) were created surgically. The animals were randomly allocated into 4 groups of 5 animals each. Group AI: one calvarial defect was filled with bioactive glass plus EMD, while the contralateral defect was filled with bioactive glass alone. The healing period was 2 weeks. Groups AII and AIII: the animals were treated in the same manner as in group AI, but the healing periods were 4 and 8 weeks, respectively. Group B: one calvarial defect was filled with EMD only, while the contralateral defect was empty (CSD). The healing period was 8 weeks. New bone formation was evaluated by radiomorphometry and histomorphometry. Results of radiomorphometry showed no significant difference in the mean optical density between bioactive glass with EMD and bioactive glass alone; no defect completely regenerated with bone. The histologic analysis revealed that defects filled with bioactive glass plus EMD in all groups contained slightly more percentage of new bone than those filled with bioactive glass alone; however, the difference was not statistically significant. The highest percentage of new bone formation was present at 8 weeks in the bioactive glass plus EMD group. Bioactive glass particles, used with or without EMD, maintained the volume and contour of the area grafted in CSD. However, they did not lead to a significant difference in bone formation when compared with CSD 8 weeks postoperatively.