EPR spectroscopy of tooth enamel: the tooth radicals and the microcrystal alignment

The paramagnetic radicals induced by radiation in dental enamel are very important because they can be related to the crystalline structure of hydroxyapatite. The R-value, that is, the ratio of the amplitude of the lines of the EPR signal due to radiation., is a measure of the degree of microcrystal alignment in human tooth enamel. The aim of this study is to underline the importance of a correct evaluation of the R-value, by using the cur-rent method to increase reproducibility in EPR spectroscopy of tooth enamel. Data with and without correction show a significant difference and, consequently, they give rise to a different valuation of microcrystal alignment.