title: Evaluation of the integrity of dental sealants by optical coherence tomography.
abstract: OBJECTIVE
  The purpose of the present research was to demonstrate images of failures into the structure of pit and fissure sealants using optical coherence tomography (OCT).
  
  
  METHODS
  Five human third molars were selected and the sealant ALPHA SEAL LIGHT/DFL was applied according to the manufacturer instructions. For evaluation of the structure of pit and fissure sealants, twenty OCT images of each tooth were performed before and after application of sealant. A total of 200 images were evaluated. A home built spectral OCT system used was operating in spectral domain (SD-OCT), at 840 nm and a measured spatial resolution of 10 μm. The system is based on the Michelson interferometer set-up and is controlled by the software OCT 800--Complex Square/LabView, that collects data and generates the image. The occlusal surfaces were scanned in a bucco-lingual direction and tomographic images parallel to long axis of tooth were obtained. After the achievement of the images by OCT, the crown of each tooth was sectioned in a occlusogingival direction (buccolingually). Images from each section were obtained and evaluated by an optical microscope. OCT and microscopic images were compared.
  
  
  RESULTS
  Representative images showed that OCT image provides the insight into sealant material. It was possible to clearly identify the internal structure of sealant and the subjacent enamel. Sealant and enamel are very well distinguished, and failures at the interior and at surface are well detected.
  
  
  CONCLUSIONS
  OCT could generate images of the features of fissures, bubbles and failures in the adaptation of sealants, opening up possibilities in the future to monitoring sealant application and retention in short and long term.
authors.affiliation: Graduate Program in Odontology, Brazil. anaksbraz@hotmail.com
authors.forename: Ana K S
authors.initials: AK
authors.lastname: Braz
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Aguiar
authors.forename: Anderson S L
authors.initials: AS
authors.lastname: Gomes
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D003743:Dental Enamel / Q000648:ultrastructure; D018772:Dental Marginal Adaptation; D006801:Humans; D006813:Humidity; D007091:Image Processing, Computer-Assisted / Q000379:methods; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D008964:Molar, Third / Q000648:ultrastructure; D010756:Phosphoric Acids / Q000737:chemistry; D010895:Pit and Fissure Sealants / Q000737:chemistry*; D012984:Software; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000295:instrumentation / Q000379:methods*; D019228:Tooth Crown / Q000648:ultrastructure
chemical_list: D010756:Phosphoric Acids; D010895:Pit and Fissure Sealants; C030242:phosphoric acid