Rat as a model for direct pulp capping research

The aim of this review is to evaluate the suitability of rat teeth in preclinical evaluation of medical materials for direct pulp capping. the international standards state clearly that only non–rodent mammals are suitable species for animal research in dentistry. however, in the past half of the century numerous research have been published using rat teeth in order to evaluate direct pulp capping, pulpotomies and tissue reactions after pulp exposure. several studies showed that the healing of rat pulp tissue after direct pulp capping was histologically comparable with human’s and other animal species’ pulp tissue. in the rat teeth including pulp tissue, basic biological reactions of the pulp tissue and the interactions seen during the different stages of wound healing are comparable with those of the other mammal species. rat teeth are a valid study model in order to provide valuable data concerning pulp tissue reaction after direct pulp capping in dentistry. therefore, the use of rats may significantly reduce the number of currently used higher animals in research. tests in higher developed animals should be limited to experiments which clarify inconsistent results. however, some technical difficulties, like the small size of rat teeth must be dealt with before undertaking any research.