Osteogenesis induced by homologous transplantation of dentine intracerebrally and subcutaneously into rats
Abstract
Hard tissue formation associated with dentine in an environment different from the dental pulp was studied by transplanting fragments of dentine between two successive litters of the same parents. The dentine was taken from the incisors of the three months old donor rats and transplanted intracerabrally or subpannicularly into 162 five days old hosts that were of the same sex as the donors. The hosts were killed after 2 to 540 days and 279 of the 324 inserted transplants recovered for histological study. The transplants were mostly found encapsulated. Cellular signs of inflammation were occasionally seen, even in long-term transplant capsules. Ependymal cell chords were found in close contact with the intracerebrally placed transplants and also at sites were bone-like tissue was present. Bone was present in conjunction with 81 transplants at 16 days or later; the majority of these were recovered from the brain tissue. The extent of bone formation varied considerably, and intact transplants were found even after 540 days. As a transplantation site the brain or the subpannicular tissue seem to differ from the dental pulp since it has been noted that intrapulpal fragments of dentine become surrounded by dentine whereas no such tissue developed in the present experiment.