Demonstration of Calcospherites in Mature Human Dentin

Abstract

Freshly extracted human teeth were fixed in formalin, decalcified in acid, embedded in paraffin and sectioned at 8[mu]. They were immersed in a 0.5% solution of papain in distilled water after removing the paraffin and hydrating the sections. The optimum time of incubation was 20 minutes at 37[degree]C. The sections were then washed and stained. Concentric rings, consisting of alternating light and dark bands 0.7[mu]. and 1.1[mu] wide respectively were seen. The structures were spherical and were calcospherites. In ordinary light and phase microscopy, the internal structure of the calcospherites could be demonstrated in unstained papain treated sections. There was no apparent effect when thin undecalcified sections were treated with papain. The concentric ring pattern could again be seen if replicas were made of the surface and metal-shadowed. The papain may remove a secondary organic material added to the original dentine matrix at the time of calcification. The concentric ring formation could not be related to the collagen fibers or to the dentinal process of the odontoblast.