An autoradiographical study of [3H]thymidine incorporation into subcutaneously transplanted mouse molar teeth. Cell...

Mice bearing either allografts or isografts of 10 day old molar teeth were injected with [3H]thymidine to identify proliferating and migrating cells within the graft and surrounding tissues. In isografts proliferating cells were found successively in the area underlying the cervix, in the cervical pulp and the coronal pulp. However, cells did not migrate from the cervical host tissue into the pulp, and it was concluded that donor cells are responsible for reparative processes in tooth isografts. Very few labelled cells were identified at any time in tooth allografts, which were not repaired. It is suggested that allografts are not repaired because allogeneic inhibition prevents the residual donor tissue from proliferating and differentiating. Inhibition of proliferation of residual cells may also account for the absence of a cell-mediated immune response to tooth allografts.