title: Near-IR imaging of cracks in teeth.
abstract: Dental enamel is highly transparent at near-IR wavelengths and several studies have shown that these wavelengths are well suited for optical transillumination for the detection and imaging of tooth decay. We hypothesize that these wavelengths are also well suited for imaging cracks in teeth. Extracted teeth with suspected cracks were imaged at several wavelengths in the near-IR from 1300-1700-nm. Extracted teeth were also examined with optical coherence tomography to confirm the existence of suspected cracks. Several teeth of volunteers were also imagedin vivoat 1300-nm to demonstrate clinical potential. In addition we induced cracks in teeth using a carbon dioxide laser and imaged crack formation and propagation in real time using near-IR transillumination. Cracks were clearly visible using near-IR imaging at 1300-nm in bothin vitroandin vivoimages. Cracks and fractures also interfered with light propagation in the tooth aiding in crack identification and assessment of depth and severity.
authors.affiliation: University of California, San Francisco, San Francisco, CA 94143-0758.
authors.forename: William A
authors.initials: WA
authors.lastname: Fried
authors.affiliation: University of California, San Francisco, San Francisco, CA 94143-0758.
authors.forename: Jacob C
authors.initials: JC
authors.lastname: Simon
authors.affiliation: University of California, San Francisco, San Francisco, CA 94143-0758.
authors.forename: Seth
authors.initials: S
authors.lastname: Lucas
authors.affiliation: University of California, San Francisco, San Francisco, CA 94143-0758.
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Chan
authors.affiliation: University of California, San Francisco, San Francisco, CA 94143-0758.
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Darling
authors.affiliation: University of California, San Francisco, San Francisco, CA 94143-0758.
authors.forename: Michal
authors.initials: M
authors.lastname: Staninec
authors.affiliation: University of California, San Francisco, San Francisco, CA 94143-0758.
authors.forename: Daniel
authors.initials: D
authors.lastname: Fried