The role of host tissue in repair of transplanted mouse molar teeth: a reappraisal of induction of odontoblasts during tooth development and repair.

After autoclaving to inactivate donor tissue, teeth were transplanted subcutaneously. Disrupted donor tissue was removed by phagocytic cells and host tissue grew into the empty pulp chamber of the graft. The host tissue failed to differentiate or form reparative dentine. This suggests that donor pulp cells carry out repair of transplanted teeth and are able to differentiate and function normally in the absence of the factors normally thought to induce their differentiation. It is suggested that during tooth development the enamel organ induces widespread potentiality in the dental papilla to differentiate into odontoblasts but papilla cells only transform into odontoblasts as they are needed. The epithelial root sheath may act only as a limiting membrane during root formation.