STUDIES OF THE COMPOSITION OF TEETH

VII. THE MOISTURE CONTENT OF CALCIFIED TOOTH TISSUES

¹ Dental Division, Walter Reed Army Institute of Research, Washington, D. C.

The moisture content of freshly extracted whole teeth and dentin was determined at 100° C. in vacuo and at 197° C. in vacuo. The maximum moisture content of freshly extracted whole teeth and dentin was established, respectively, at 9.32 ± .37 per cent and 10.00 ± .55 per cent. The maximum moisture content of whole teeth and powdered enamel and dentin previously conditioned at 82° ± 3° F. and 36 to 49 per cent relative humidity was established respectively, at 8.0 ± .24 per cent, 0.81 ± .03 per cent, and 8.7 ± .12 per cent when subjected to 197° C. in vacuo. Rehydration of such tissues at 82° F. and 36 to 49 per cent relative humidity restored some but not all the moisture. Teeth, enamel, and dentin conditioned at 98° F. and 100 per cent relative humidity contained 8.2 ± .27 per cent, 2.2 ± .04 per cent, and 15.6 ± .15 per cent moisture, respectively. Rehydration of such tissues at 98° F. and 100 per cent relative humidity restored some but not all of their moisture content.