Basic mechanisms of cytodifferentiation and dentinogenesis during dental pulp repair

Based on recent literature, the specific potential of mature pulp cells to differentiate into polarized cells able to elaborate reparative dentin is described. These odontoblast-like cells are distinguished, by morphological criteria, from the other matrix-formative cells involved in non-specific defensive mechanisms of dental pulp. The suitable tissue conditions and the normal cascade of reparative events, allowing initiation of dentinogenesis in sites of amputated pulp, are presented. This is followed by a review of current observations on specific dentinogenic events, induced in various culture systems or in intrapulpal sites of mature teeth by artificial bio-molecules or bio-matrices. Data from these experiments are focused on the role of extracellular matrix molecules and growth factors in acquisition of the odontoblast-like cell phenotype and initiation of reparative dentinogenesis.