Analysis of dental hard tissue by computerized microdensitometry.

One method of quantitating mineral content in thin sections of dental hard tissue is microdensitometry of contact radiographs. This method is often applied to analysis of artificial caries lesions. Because there is great inter- and intra-tooth variability, a single microdensitometric scan will not accurately reflect the content or distribution of mineral within an individual lesion, or within a group of lesions. To increase the number of replicates than can be handled routinely, a computer-driven microdensitometer has been used with a step series of aluminum and enamel to quantitate mineral content values at approximately 1-micron intervals. Accurate assessment of an individual lesion was made possible by averaging multiple scans of the lesion on each of several thin sections prepared from the lesion. Mean mineral profiles of treatment groups were then made from the profiles of the individual lesion. These data reduction techniques allowed for a large number of replicates to be used in the measurement of remineralization. The computerized microdensitometric system described here was developed to allow for an objective, quantitative analysis of the mineral content of dental hard tissue.