Trapped Water of Dental Enamel

Abstract

RECENT investigations with polarizing microscopy have indicated that some of the water of dental enamel is not easily removed by dehydrating methods. Somewhat more severe treatment of enamel is necessary to remove the last portion of water and these more drastic conditions bring about irreversible changes in enamel¹. A distinction between firmly and loosely held water would appear to be possible with the aid of wide line nuclear magnetic resonance spectrometry. On the basis of its narrower signal, relatively free water may be distinguished by this technique from water which is bound. It has been possible to demonstrate that the narrow-line signal due to water protons in suspensions of wheat starch became wider as the degree of gelation and amount of fixation of water increased².