title: Remineralization of in vitro dental caries assessed with polarization-sensitive optical coherence tomography.
abstract: Polarization-sensitive optical coherence tomography (PS-OCT) is potentially useful for imaging the nonsurgical remineralization of dental enamel. This study uses an all-fiber-based PS-OCT system operating at 1310 nm to image demineralized and fluoride-enhanced remineralized artificial lesions. PS-OCT images of lesions before and after remineralization are compared with the relative mineral loss DeltaZ (%vol x microm), obtained from high resolution digital microradiography (DM), and chemical composition changes by infrared spectroscopy. Severe early artificial caries show a significant increase in perpendicular-axis integrated reflectivity after remineralization. After sectioning the samples, DM demonstrates that the lesions remineralized with new mineral and the lesion surface zone show significant restoration of mineral volume. PS-OCT and DM both do not show a major change in lesion depth. For less severe artificial caries, the perpendicular-axis image resolves the scattering and depolarization of an outer growth layer after remineralization. This outer layer has a mineral volume close to that of sound enamel, and spectroscopic analysis indicates that the layer is a highly crystalline phase of apatite, without carbonate substitutions that increase the solubility of sound enamel. This study determines that PS-OCT can image the effects of fluoride-enhanced remineralization of mild and severe early artificial in vitro caries.
authors.affiliation: University of California, Department of Preventive and Restorative Dental Sciences, San Francisco, California 94143, USA.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Jones
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Darling
authors.forename: John D B
authors.initials: JD
authors.lastname: Featherstone
authors.forename: Daniel
authors.initials: D
authors.lastname: Fried
mesh_terms: D015519:Bone Density / Q000187:drug effects*; D002113:Calcification, Physiologic / Q000187:drug effects*; D002327:Cariostatic Agents / Q000627:therapeutic use; D003731:Dental Caries / Q000188:drug therapy* / Q000473:pathology*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005460:Fluorides, Topical / Q000627:therapeutic use*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D066298:In Vitro Techniques; D008859:Microscopy, Polarization / Q000295:instrumentation* / Q000379:methods; D012031:Refractometry / Q000295:instrumentation / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000295:instrumentation* / Q000379:methods; D016896:Treatment Outcome
chemical_list: D002327:Cariostatic Agents; D005460:Fluorides, Topical