Quantification of free water in human dental enamel

The amount of free water in 50 samples of air-dried enamel from permanent and deciduous teeth was measured by the Karl Fischer method. Samples included both contemporary and burial specimens. The mean values obtained showed that free water constituted about 1% of enamel mass. However, the range of individual values varied considerably, from 0.56 to 1.48%. The proportion of free water did not seem to depend on the patient's age, the type of tooth, or the relationship between the tooth and its oral environment. On the other hand, the deciduous enamel tested displayed a mean free water content that was three times the mean for the permanent teeth (3.01 vs. 1.00%) and the five burial teeth, a mean content of 1.68%.