1 February 2011 Terahertz pulsed imaging study to assess remineralization of artificial caries lesions
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J. of Biomedical Optics, 16(2), 026001 (2011). doi:10.1117/1.3540277
We compare terahertz-pulsed imaging (TPI) with transverse microradiography (TMR) and microindentation to measure remineralization of artificial caries lesions. Lesions are formed in bovine enamel using a solution of 0.1 M lactic acid/0.2% Carbopol C907 and 50% saturated with hydroxyapatite adjusted to pH 5.0. The 20-day experimental protocol consists of four 1 min treatment periods with dentifrices containing 10, 675, 1385, and 2700 ppm fluoride, a 4-h/day acid challenge, and, for the remaining time, specimens are stored in a 50:50 pooled human/artificial saliva mixture. Each specimen is imaged at the focal point of the terahertz beam (data-point spacing = 50 μm). The time-domain data are used to calculate the refractive index volume percent profile throughout the lesion, and the differences in the integrated areas between the baseline and post-treatment profiles are used to calculate ΔΔZ(THz). In addition, the change from baseline in both the lesion depth and the intensity of the reflected pulse from the air/enamel interface is determined. Statistically significant Pearson correlation coefficients are observed between TPI and TMR/microindentation (P < 0.05). We demonstrate that TPI has potential as a research tool for hard tissue imaging.
David R. Churchley, Richard J. M. Lynch, Frank Lippert, Jennifer S. O'Bryan Eder, Jesse Alton, Carlos Gonzalez-Cabezas, "Terahertz pulsed imaging study to assess remineralization of artificial caries lesions," Journal of Biomedical Optics 16(2), 026001 (1 February 2011). https://doi.org/10.1117/1.3540277

Terahertz radiation


Refractive index

Dental caries


Statistical analysis

Data acquisition

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