THE MODULATORY ROLE OF CEMENTUM MATRIX ON OSTEOBLASTIC CELLS IN-VITRO

The formation of new cementum is an important issue in clinical period ontology, as cementum is required to provide attachment for newly form ed periodontal tissues to the root surface. In this study a model of c ementogenesis in vitro was used in order to test the effects of root s urface demineralization on the migration, attachment and formation of a cementum-like tissue by osteoblastic cells cultured on cementum and to test the specificity of cementum matrix in modulating those effects by comparison of root cn-cultures with bone co-cultures. It was demon strated that root surface demineralization did not significantly alter the orientation? number and attachment of cells to the root co-cultur es. The results also demonstrated that cementum and bone matrix appear to behave differently in culture, as seen by their distinct action on the morphological profile of the attached cells and the extracellular matrix deposited by these cells. These results demonstrate that altho ugh cementum matrix appears to stimulate the production of cementum-li ke tissue, this action is not confined to cementum matrix alone, since a similar material was also deposited on dentine and bone surfaces. T hus, these results do not support a specific action of cementum matrix on the modulation of the cementoblast phenotype. The use of co-cultur es of neonatal rat calvaria cells with root slices represents a promis ing model of cementogenesis in vitro: however, studies should be under taken towards the indentification of markers to distinguish between ce mentoblast and osteoblast phenotypes in order to further validate this model.