Small angle X-ray scattering (SAXS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) have been used to look at enamel from nine premolars, three each from individuals in low, medium and high risk caries groups. Only SAXS was able to detect consistent differences between any of the groups. In enamel from the high caries risk group, the micropores between the hydroxyapatite crystals were laminar. In enamel from the low caries risk group, the micropores were cylindrical. Other parameters varied between teeth but were not correlated with caries risk.