Relationship between fluoride distribution and histological structure of permanent human cementum.

The relationship between fluoride distribution and histological structure of human cementum was studied.The materials used were cementum of of the root apex of thirty canine teeth which were extracted from nine subjects averaging 55.9 years of age.Distribution of fluoride in cementum was obtained from ground cementum specimens through the abrasive micro-sampling method (Weatherell, et al., 1985). Histological findings were obtained from microscopic observation of specimens without stain and with hematoxylin stain.X-ray micro-analysis on the specimens indicated that the phosphorus concentration was constant at approximately 12.2% in all specimens, regardless of depth or structure of the cementum. This phosphorus concentration was used to calculate the mass of each specimen.The graphs of fluoride distribution were superimposed on the photographs of the magnified image of histological structure of cementum.The results and conclusion were as follows:1. Each individual had approximately the same distribution of fluoride concentration in all his canines, which means that each subject has his own characteristic pattern of fluoride distribution.2. Fluoride concentration was high in the acellular cementum and was low in the cellular cementum.3. Fluoride concentration was relatively high on“the incremental lines”but it was relatively low between the lines.4. There was a close relationship between the pattern of fluoride distribution and histological stiucture of the cementum within each individual.