The Ca, P, Na, and Ash Content at Different Depths in Caries

¹ Eastman Dental Dispensary and University of Rochester, Rochester, New York

The composition of carious material was determined at different depths within cavities which had previously been studied in vivo for their pH response to glucose, buffering, and excavation. The loss in weight on ashing indicated that the outer layers of carious material had a lower mineral content than the inner layers. All samples were far less mineralized than normal dentin. The major portion of the ash was calcium and phosphorus. The mean calcium/phosphorus ratios were somewhat higher within the depths than at the surface of the cavities. On an ash-weight basis, the sodium content showed higher values in the surface layers.