A study of the mineral phase of pulp calcification.

Physico-chemical properties of pulp calcification were studied by means of X-ray microbeam diffraction, electron spin resonance (ESR), X-ray energy-dispersive analysis, and chemical analysis. The material was obtained from the second molar of the right mandible of a 25-year-old woman. X-ray diffraction and ESR analyses showed that calcium salts of the calcification are deposited in the form of apatitie, possibly carbonate-containing apatite. Furthermore, the mineral phase of the calcification was found to be similar to that of bone rather than that of dentin with regard to crystallinity and inorganic content. An unexpected finding was that high concentrations of iron were detected in some areas near the surface of the calcification. The question remains open as to what role, if any, iron may play in the formation of pulp calcification.