The immunogenicity of tooth allografts in rats

Orthotopic and heterotopic tooth allografts stimulated the production of alloantibodies in rats incompatible at the major histocompatibility locus. The immunogenicity of whole tooth grafts was slightly diminished but not eliminated by sealing the pulp cavity prior to grafting. Suspensions of dentine in saline elicited alloantibody formation on i.p. injection into allogeneic hosts. Orthotopic tooth allografts, but not heterotopic grafts, were as effective as skin allografts at stimulating second set rejection of challenging skin grafts. Orthotopic tooth allografts were indistinguishable from syngeneic grafts on histological examination over the period 1-6 weeks after grafting. The occurrence of alloantibody formation after tooth grafting was capricious, and this, combined with the histological difficulty of distinguishing syngeneic from allogeneic grafts, and also the differing capacity of orthotopic and heterotopic tooth allografts to provoke accelerated skin grafts rejection, probably accounts for some of the differences of opinion expressed previously on the immunogenicity of grafted teeth.