Inability of calcium hydroxide to induce reparative dentinogenesis at non-peripheral sites of dog dental pulp.

The ability of 2 calcium hydroxide-containing materials to induce initiation of reparative dentinogenesis was tested at sites remote from the dentinogenically-active regions of the pulp periphery. Pieces of the cements, Dycal and Life, were implanted in central parenchymal sites of dog dental pulps for periods of 6, 14 and 42 days, respectively. Similar pieces were placed in peripheral capping sites as controls. The responses were analyzed by light and transmission electron microscopy. Induction of tubular dentin matrix lined with elongated and polarized odontoblast-like cells was only seen at peripheral capping sites. In response to the centrally implanted cements, only atubular hard tissue with lining fibroblast-like cells was deposited.