title: Monitoring of cariogenic demineralization at the enamel-composite interface using swept-source optical coherence tomography.
abstract: The aim of this study was to evaluate enamel demineralization at composite restoration margins caused by cariogenic biofilm using swept-source optical coherence tomography (SS-OCT).
  
  
  
  Sixty round-shaped cavities were prepared on the mid-buccal enamel surface of extracted human molars. The cavities were restored with Estelite Flow Quick flowable composite using either Clearfil SE Bond or Clearfil Tri-S Bond ND bonding agents. Streptococcus mutans suspension was applied to form a cariogenic biofilm on the surface. After 1, 2, or 3 weeks of incubation (n=10), the biofilm was removed to observe the carious demineralization at the cavosurface margins using SS-OCT. The gap along the enamel-composite interface was recorded on each adhesive system. Confirmatory direct observation was accomplished at the same location using confocal laser scanning microscope.
  
  
  
  The demineralized enamel around the restorations was observed as a zone of intensified brightness in SS-OCT. The demineralized lesion on the cervical enamel was significantly deeper than that on the occlusal enamel (p<0.05). However, the extension of enamel demineralization at the enamel-composite interface was significantly deeper at the occlusal wall than the cervical wall (p<0.05). The extension in Tri-S Bond ND group was significantly deeper than in SE Bond group (p<0.05). A significant increase in gap formation was found after the extension of demineralization compared with the baseline.
  
  
  
  The carious demineralization around composite restorations were observed as a bright zone in SS-OCT during the process of bacterial demineralization. SS-OCT appears to be a promising modality for the detection of caries adjacent to an existing restoration.
authors.affiliation: Department of Cariology and Operative Dentistry, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Horie
authors.affiliation: Department of Cariology and Operative Dentistry, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. Electronic address: shimada.ope@tmd.ac.jp.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Shimada
authors.affiliation: Department of Cariology and Operative Dentistry, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; Endowed Department of International Oral Health Science, Tsurumi University, School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan.
authors.forename: Khairul
authors.initials: K
authors.lastname: Matin
authors.affiliation: Oral Prosthetic Engineering, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Masaomi
authors.initials: M
authors.lastname: Ikeda
authors.affiliation: Department of Restorative Dentistry, University of Washington School of Dentistry, 1959 NE Pacific Street, Box 357456, Seattle, WA 98195-7456, USA.
authors.forename: Alireza
authors.initials: A
authors.lastname: Sadr
authors.affiliation: Department of Advanced Dental Research, Center of Advanced Medicine for Dental and Oral Diseases, National Center for Geriatrics and Gerontology, 7-430 Morioka-cho, Obu, Aichi 474-8511, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Sumi
authors.affiliation: Department of Cariology and Operative Dentistry, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D003188:Composite Resins; D003731:Dental Caries; D003743:Dental Enamel; D003793:Dental Restoration, Permanent; D008963:Molar; D019279:Resin Cements; D041623:Tomography, Optical Coherence; D017001:Tooth Demineralization
chemical_list: C515604:Clearfil Tri-S Bond; D003188:Composite Resins; D019279:Resin Cements
keywords: Biofilm; Caries; Composite restoration; Demineralization; Enamel; Gap; SS-OCT; Streptococcus mutans