title: Evaluation of the marginal fit at implant-abutment interface by optical coherence tomography.
abstract: Vertical misfit of implant-abutment interface can affect the success of implant treatment; however, currently available modalities have limitations to detect these gaps. This study aimed to evaluate implant-abutment gaps in vitro using optical coherence tomography (OCT). Vertical misfit gaps sized 50, 100, 150, or 200 μm were created between external hexagonal implants and titanium abutments (Nobel Biocare, Göteborg, Sweden). A porcine gingival tissue slice, 0.5, 1.0, 1.5, or 2.0 mm in thickness, was placed on each implant-abutment interface. The gaps were evaluated by swept-source OCT at a center wavelength of 1330 nm (Panasonic Healthcare, Ehime, Japan) with beam angles of 90, 75 and 60 deg to the implant long-axis. The results suggested that while the measurements were precise, gap size and gingival thickness affected the sensitivity of detection. Gaps sized 100 μm and above could be detected with good accuracy under 0.5- or 1.0-mm-thick gingiva (GN). Around 70% of gaps sized 150 μm and above could be detected under 1.5-mm-thick GN. On the other hand, 80% of gaps under 2.0-mm-thick GN were not detected due to attenuation of near-infrared light through the soft tissue. OCT appeared as an effective tool for evaluating the misfit of implant-abutment under thin layers of soft tissue.
authors.affiliation: Tokyo Medical and Dental University, Gerodontology and Oral Rehabilitation, Department of Gerontology and Gerodontology, Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kikuchi
authors.affiliation: Tokyo Medical and Dental University, Gerodontology and Oral Rehabilitation, Department of Gerontology and Gerodontology, Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Norihisa
authors.initials: N
authors.lastname: Akiba
authors.affiliation: Tokyo Medical and Dental University, Department of Cariology and Operative Dentistry, Global Center of Excellence Program, International Research Center for Molecular Science in Tooth and Bone Diseases, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Alireza
authors.initials: A
authors.lastname: Sadr
authors.affiliation: Center of Advanced Medicine for Dental and Oral Diseases, National Center for Geriatrics and Gerontology, Department for Advanced Dental Research, 36-3, Gengo, Morioka, Obu, Aichi 474-8511, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Sumi
authors.affiliation: Tokyo Medical and Dental University, Department of Cariology and Operative Dentistry, Global Center of Excellence Program, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
authors.affiliation: Tokyo Medical and Dental University, Gerodontology and Oral Rehabilitation, Department of Gerontology and Gerodontology, Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Minakuchi
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D059605:Dental Implant-Abutment Design; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D010519:Periodontium / Q000033:anatomy & histology*; D012031:Refractometry; D013552:Swine; D041623:Tomography, Optical Coherence / Q000379:methods*