Experimental dentin-based approaches to tissue regeneration in vital pulp therapy

The potential direct induction of odontoblastlike cell differentiation at the surface of implanted dentin matrix has been tested in a series of capping experiments. Pieces of Teflon (control) or autogenous dentin matrix were placed in contact with the wound surface at a conventional capping situation, or at the dentinal base of the cavity at a distance from the exposed pulp periphery. Tissue responses were studied by light microscopy after periods of 2 and 4 weeks. Partial degradation of the dentin matrix implants was seen. Formation of a tubular calcified matrix, occasionally followed by tubular reparative dentin, was consistently detected in association with dentinal particles. The area between the traumatized dental pulp periphery and the capping material had been occupied by a well-vascularized tissue, regardless of the capping material and postoperative time period. Traces of calcified matrix were detected along the cut dentinal walls. The present data indicate that dentin matrix is limited in its ability to directly induce odontoblastlike cell differentiation and reparative dentin formation at the surface of mechanically exposed pulp of mature teeth. Furthermore, it seems that the traumatized mature pulp maintains the ability to grow, while a calcifying potential could be expressed by this growing part of the pulp core.