Histology of external and internal resorption.

Seven cases of resorption in teeth have been described. Three had large internal cavities penetrating the dentine to or from the exterior. One had internal resorption in two separate locations and another had internal resorption which may have been precipitated by carious involvement of the pulp. Two cases of external resoprtion were quite dissimilar, one possibly a reaction to canal infection, the other idiopathic. Various types of calcified material were found in the areas of resorption and odontoclasts were found in one case.