Enamel matrix derivative prolongs primary osteoblast growth

Enamel matrix derivative (EMD) secreted by cells of the epithelial root sheath plays an important role in cementogenesis and periodontal tissue formation. The mechanisms by which EMD influences cell function are not known. The purpose of this study was to determine the effect of EMD on cell growth of primary mouse osteoblasts. Osteoblasts were digested from 6- to 8-day-old mouse calvaria and plated into 6-well cell culture plates at an initial density of 5000 cells/cm2. After 24-h incubation with Dulbecco's modified eagle medium (DMEM) supplemented with 10% fetal bovine serum, cells were incubated in three different groups of media: DMEM only as control, DMEM with 25 microg/ml EMD, and DMEM with 100 microg/ml EMD. At days 3, 7, 10, and 14, the total cell number per well was calculated, and cell morphology was examined. At each observation period the number of cells in the EMD groups was significantly greater (ANOVA, p < 0.01) than that in the control group. EMD had a greater effect on osteoblast survivor in the higher concentration than in the lower concentration. Furthermore normal morphology of the primary osteoblasts was maintained in the EMD groups. These results suggest that EMD prolongs primary osteoblast growth and may have an effect on osteoblasts during periodontal regeneration.