title: Use of optical coherence tomography for assessment of dental caries: quantitative procedure.
abstract: A method for quantitative assessment of dental caries using optical coherence tomography (OCT) was demonstrated. Development of caries lesions in 15 bovine teeth, by demineralization in acidic buffer solution, was quantitatively assessed daily for 3 days, using OCT. An OCT system which can collect A-scans (depth versus reflectivity curve), B-scans (longitudinal images) and C-scans (transverse images at constant depth) was used. While the B- and C-scans qualitatively described the lesion detected, the A-scan which showed the depth (mm) resolved reflectivity (dB) of the tooth tissue was used for the quantitative analysis. After a simple normalization procedure to determine the actual depth the light travelled into the tooth tissue, the area (R) under the A-scan was quantified as a measure of the degree of reflectivity of the tissue. The result showed that R (dB mm) decreased with increasing demineralization time. The percentage reflectivity loss (R%) in demineralized tissue, which related to the amount of mineral loss, was also calculated, and it was observed that R% increased with increasing demineralization time. It was concluded that with the above procedure, OCT could quantitatively monitor the mineral changes in a caries lesion on a longitudinal basis.
authors.affiliation: Department of Community Dentistry, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900, USA. amaechi@uthscsa.edu
authors.forename: B T
authors.initials: BT
authors.lastname: Amaechi
authors.forename: S M
authors.initials: SM
authors.lastname: Higham
authors.forename: A G
authors.initials: AG
authors.lastname: Podoleanu
authors.forename: J A
authors.initials: JA
authors.lastname: Rogers
authors.forename: D A
authors.initials: DA
authors.lastname: Jackson
mesh_terms: D000818:Animals; D002417:Cattle; D003731:Dental Caries / Q000175:diagnosis*; D003743:Dental Enamel / Q000473:pathology; D003804:Dentin / Q000473:pathology; D007368:Interferometry; D008027:Light; D008903:Minerals / Q000737:chemistry; D055095:Optics and Photonics; D012031:Refractometry; D013997:Time Factors; D014054:Tomography / Q000379:methods*; D017001:Tooth Demineralization / Q000175:diagnosis
chemical_list: D008903:Minerals