Modulated (frequency-domain) infrared photothermal radiometry (PTR) is used as a dynamic quantitative dental inspection tool complementary to modulated luminescence (LM) to quantify sound enamel or dentin. A dynamic high-spatial-resolution experimental imaging setup, which can provide simultaneous measurements of laser-induced modulated PTR and LM signals from defects in teeth, has been developed. Following optical absorption of laser photons, the experimental setup can monitor simultaneously and independently the nonradiative (optical-to-thermal) energy conversion by infrared PTR and the radiative deexcitation by LM emission. The relaxation lifetimes (τ<sub>1</sub>, τ<sub>2</sub>) and optical absorption, scattering, and spectrally averaged infrared emission coefficients (μ<sub>α</sub>, μ<sub><i>s</i></sub>, μ̄<sub>IR</sub>) of enamel are then determined with realistic three-dimensional LM and photothermal models for turbid media followed by multiparameter fits to the data. A quantitative band of values for healthy enamel with respect to these parameters can be generated so as to provide an explicit criterion for the assessment of healthy enamel and, in a future extension, to facilitate the diagnosis of the onset of demineralization in carious enamel.
© 2002 Optical Society of America
Lena Nicolaides, Chris Feng, Andreas Mandelis, and Stephen H. Abrams, "Quantitative Dental Measurements by use of Simultaneous Frequency-Domain Laser Infrared Photothermal Radiometry and Luminescence," Appl. Opt. 41, 768-777 (2002)