Inductive influences of demineralized dentin and bone matrix on pulp cells: an approach of secondary dentinogenesis

The effects of demineralized dentin and bone matrix on dental ectomesenchymal cells were evaluated after observation periods of two or three weeks. Autogenous dentin and bone matrix, obtained from the crowns of primary molars or maxillary cortical bone, respectively, were demineralized with 3% acetic acid and implanted into pulpal or papilla sites of erupting dog teeth: first molars, fourth premolars, and canines. Dentin histogenesis associated with odontoblastic arrangement was demonstrated in relation to all dentin implants in pulpal sites. Deposition of osteodentin, followed in some areas by tubular predentin formation, was observed in contact with bone implants in pulpal sites. In papilla sites, the dentin implantation exhibited bone-like matrix formation, while bone implants were encapsulated by connective tissue. The interactions of pulp cells with demineralized dentin matrix constitute a model for experimental induction of secondary dentinogenesis and odontoblast-like cell differentiation.