title: Imaging artificial caries on the occlusal surfaces with polarization-sensitive optical coherence tomography.
abstract: Polarization-sensitive optical coherence tomography (PS-OCT) is a nondestructive imaging system that can utilize near-infrared (IR) light to produce depth-resolved images of dental enamel and has the potential to monitor early enamel occlusal caries. The objective of this study was to investigate the relationship between the magnitude of backscattered light and depolarization recorded by PS-OCT with changes in the enamel mineral volume in an artificial caries model. Artificial lesions were created on a selected region on the occlusal surfaces of sound posterior teeth (n=10) using a well-characterized 14-day pH cycling model. An all-fiber-based PS-OCT system operating at 1,310 nm was used to collect serial images at day 0 and day 14 prior to tooth sectioning. The quantitative mineral content profile and relative mineral loss, DeltaZ (%volxmicrom), of the carious enamel samples were obtained from transverse sections using high-resolution digital microradiography (DM). Line profiles of PS-OCT and DM images were used to evaluate the artificial caries severity and depth. The integrated reflectivity of the perpendicular-axis PS-OCT image, quantifying lesion severity, was correlated to the DeltaZ of the caries lesions. There was also a strong correlation between the lesion depth calculated from both imaging modalities. PS-OCT can image and quantify artificial occlusal caries by measuring the increase in backscattering and depolarization of near-IR light. This optical method has promising applications for in vivo detection and monitoring of early enamel occlusal caries.
authors.affiliation: Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, CA 94143-0758, USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Jones
authors.forename: C L
authors.initials: CL
authors.lastname: Darling
authors.forename: J D B
authors.initials: JD
authors.lastname: Featherstone
authors.forename: D
authors.initials: D
authors.lastname: Fried
mesh_terms: D000704:Analysis of Variance; D003731:Dental Caries / Q000175:diagnosis*; D003732:Dental Caries Activity Tests; D003743:Dental Enamel; D042241:Early Diagnosis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008027:Light; D008852:Microradiography / Q000379:methods; D012542:Scattering, Radiation; D041623:Tomography, Optical Coherence / Q000295:instrumentation / Q000379:methods*