[27] Measurement of mineral gain and loss on dental enamel and dentin using confocal microscopy

The chapter describes briefly the current methodologies used to measure mineral gain and loss in dental enamel and dentin using confocal microscopy. The studies described in the chapter support the use of confocal laser scanning microscopy (CLSM) as an effective technique for measuring in vitro mineral changes in dental tissues. Enamel is more mineralized than bone or dentin. It is approximately 99% mineral by weight and averages 87% mineral by volume. Most of the research up to date has focused on the two-dimensional (2-D) analysis of affected areas, not taking into account the potential for optical sectioning of the teeth that CLSM offers. Studies have focused on the measurement of fluorescent dye penetration in the porosities of demineralized tissue, on the measurement of changes in autofluorescence of the tissue, or on the changes in the reflection of light from the lesion. Analyses have been done on intact surfaces and cross sections, with the latter being studied most frequently. Future studies need to focus on the three-dimensional (3-D) analysis of carious lesions, as new information could be gained by analyzing volume changes and mineral distributions.