title: Detection of root surface fractures with swept-source optical coherence tomography (SS-OCT).
abstract: OBJECTIVE
  The purpose of this study was to compare optical coherence tomography (OCT) with the existing technologies, to assess its accuracy and utility in detecting vertical root fractures of extracted human teeth.
  
  
  BACKGROUND
  The detection of root fractures in teeth that have undergone root canal treatment is challenging because of the great difficulty in differentiating these fractures from morphologic or radiographic anomalies. OCT methods are based on depth-resolved optical reflectivity and have been developed to reduce the invasiveness and radiation exposure inherent to other techniques.
  
  
  METHODS
  Twelve extracted human mandibular teeth (totaling 25 roots) that were free of caries, calculus, and root treatment were used, and assessed by microfocus computed tomography, the current gold standard for fracture detection. The ability of appropriately trained observers to detect root fractures using visual, microscopic, and swept-source OCT (SS-OCT) techniques were compared. micro-CT and SS-OCT produce three-dimensional images of the tooth from which to diagnose fractures, but CT scanning involves radiation exposure that is not required in SS-OCT.
  
  
  RESULTS
  Seventeen of the 25 roots were found to have fractures by microfocus CT. These findings were replicated by SS-OCT, which revealed fractures exhibiting identical origin, size, and angulation within the root. We found that SS-OCT gave results compatible to the gold standard technique, and that SS-OCT and microscopy were more effective for identifying root fractures than was visual observation alone.
  
  
  CONCLUSIONS
  SS-OCT may represent a novel, noninvasive, noncontact and nonexposure alternative to the conventional methods used for assessing root fractures in teeth.
authors.affiliation: Pulp Biology and Endodontics, Department of Oral Restitution, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Yoshioka
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sakaue
authors.forename: Hitomi
authors.initials: H
authors.lastname: Ishimura
authors.forename: Arata
authors.initials: A
authors.lastname: Ebihara
authors.forename: Hideaki
authors.initials: H
authors.lastname: Suda
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Sumi
mesh_terms: D006801:Humans; D041623:Tomography, Optical Coherence / Q000379:methods*; D014082:Tooth Fractures / Q000175:diagnosis*; D014092:Tooth Root / Q000293:injuries*; D055114:X-Ray Microtomography