Induction of heterotopic bone formation by demineralized dentin in guinea pigs: antigenicity of the dentin matrix

. Fifty autogenous, 120 allogenic and 40 xenogenic demineralized dentin specimens as‐well as 36 undemineralized allogenic specimens were implanted in the abdominal muscles of 74 male guinea pigs for periods ranging from 4 to 12 weeks. An experimental model for the first and second set reaction in allogenic ear skin grafts was established in 10 male guinea pigs. The mean survival times of the first and second sets of these grafts were 10.1 days, s.d. = 1.57 and 5.2 days, s.d. = 0.78, respectively. Repeated implantation of both undemineralized, and demineralized and lyophilized allogenic dentin evoked an immune response in the host resulting in an accelerated skin graft rejection. Furthermore, in the second and third sets of implants the bone inducing process was either prevented (undemineralized dentin) or reduced (demineralized and lyophilized dentin). Xenogenic demineralized dentin failed to induce osteogenesis, probably due to an intense host immune response. The first set of allogenic demineralized dentin implants, on the other hand, induced bone formation in a high percentage of cases, it even gave the impression of enhancing the induction process compared to autogenous dentin.