Non-reflective photography with a polarizer and its application in assessing dental fluorosis

Abstract

In assessing enamel mottling and opacities, like dental fluorosis, on the photographs customarily taken with a stroboscope, it is often difficult to detect the affected areas because strongly reflected spots or areas are liable to appear on the tooth surface in the photograph.
To resolve the problem, we developed a non-reflective photography using two dichroic polarizers, one in front of the stroboscope and the other before the lens of the camera.
We applied the method to assess the severity of dental fluorosis of schoolchildren residing in a fluoride-rich water district. The method made the appearance of the mottling and opaque areas on dental enamel clearer than in customary photography. The severity grades of dental fluorosis assessed on the non-reflective photograph agreed with the grade levels from inspection in general, but had a tendency to be evaluated as severer in some cases.
To assess the mottling on dental enamel in dental fluorosis more objectively, it is recommendable to compare the findings from inspection, customary photographes, and non-reflective photographs of the object, to evaluate the three together, and then decide on a severity grade.
This technique can also be used for taking non-reflective photographes of other biological materials.