Lesion dehydration rate changes with the surface layer thickness during enamel remineralization

A transparent highly mineralized outer surface zone is formed on caries lesions during remineralization that reduces the permeability to water and plaque generated acids. However, it has not been established how thick the surface zone should be to inhibit the penetration of these fluids. Near-IR (NIR) reflectance coupled with dehydration can be used to measure changes in the fluid permeability of lesions in enamel and dentin. Based on our previous studies, we postulate that there is a strong correlation between the surface layer thickness and the rate of dehydration. In this study, the rates of dehydration for simulated lesions in enamel with varying remineralization durations were measured. Reflectance imaging at NIR wavelengths from 1400-2300 nm, which coincides with higher water absorption and manifests the greatest sensitivity to contrast changes during dehydration measurements, was used to image simulated enamel lesions. The results suggest that the relationship between surface zone thickness and lesion permeability is highly non-linear, and that a small increase in the surface layer thickness may lead to a significant decrease in permeability.

[1]  Daniel Fried,et al.  High contrast reflectance imaging of simulated lesions on tooth occlusal surfaces at near‐IR wavelengths , 2013, Lasers in surgery and medicine.

[2]  I A Pretty,et al.  Occlusal caries detection by using thermal imaging. , 2010, Journal of dentistry.

[3]  N. Pender.  Detection, assessment, diagnosis and monitoring of caries (2009) , 2010 .

[4]  Daniel Fried,et al.  Activity assessment of root caries lesions with thermal and near‐IR imaging methods , 2017, Journal of biophotonics.

[5]  F. Pernus,et al.  Near-infrared hyperspectral imaging of water evaporation dynamics for early detection of incipient caries. , 2014, Journal of dentistry.

[6]  Daniel Fried,et al.  Assessment of remineralization via measurement of dehydration rates with thermal and near-IR reflectance imaging. , 2015, Journal of dentistry.

[7]  Daniel Fried,et al.  Imaging caries lesions and lesion progression with polarization-sensitive optical coherence tomography , 2002, SPIE BiOS.

[8]  D. Fried,et al.  Remineralization of Enamel Caries Can Decrease Optical Reflectivity , 2006, Journal of dental research.

[9]  Hobin Kang,et al.  Nondestructive monitoring of the repair of enamel artificial lesions by an acidic remineralization model using polarization-sensitive optical coherence tomography. , 2012, Dental materials : official publication of the Academy of Dental Materials.

[10]  Cynthia L. Darling,et al.  Multispectral near-IR reflectance and transillumination imaging of teeth , 2011, Biomedical optics express.

[11]  Kenneth H. Chan,et al.  Multispectral near‐IR reflectance imaging of simulated early occlusal lesions: Variation of lesion contrast with lesion depth and severity , 2014, Lasers in surgery and medicine.

[12]  B. Clarkson,et al.  Dental caries; the disease and its clinical management , 2004 .

[13]  Daniel Fried,et al.  Remineralization of in vitro dental caries assessed with polarization-sensitive optical coherence tomography. , 2006, Journal of biomedical optics.

[14]  Daniel Fried,et al.  Use of 2D images of depth and integrated reflectivity to represent the severity of demineralization in cross‐polarization optical coherence tomography , 2015, Journal of biophotonics.

[15]  Daniel Fried,et al.  Infrared Methods for Assessment of the Activity of Natural Enamel Caries Lesions , 2016, IEEE Journal of Selected Topics in Quantum Electronics.

[16]  Masatoshi Ando,et al.  Pilot clinical study to assess caries lesion activity using quantitative light-induced fluorescence during dehydration , 2017, Journal of biomedical optics.

[17]  H. Margolis,et al.  Enhanced Enamel Remineralization under Acidic Conditions in vitro , 2008, Journal of dental research.