Three-dimensional assessment of proximal contact enamel using optical coherence tomography

Thwe Zin Ei; Yasushi Shimada; Ahmed Abdou; Alireza Sadr; Masahiro Yoshiyama; Yasunori Sumi; Junji Tagami

doi:10.1016/j.dental.2019.01.008

Three-dimensional assessment of proximal contact enamel using optical coherence tomography

Dent Mater. 2019 Apr;35(4):e74-e82. doi: 10.1016/j.dental.2019.01.008. Epub 2019 Feb 13.

Authors

Thwe Zin Ei¹, Yasushi Shimada², Ahmed Abdou³, Alireza Sadr⁴, Masahiro Yoshiyama⁵, Yasunori Sumi⁶, Junji Tagami¹

Affiliations

¹ Department of Cariology and Operative Dentistry, Division of Oral Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
² Department of Cariology and Operative Dentistry, Division of Oral Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Department of Operative Dentistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan. Electronic address: shimada.ope@okayama-u.ac.jp.
³ Department of Cariology and Operative Dentistry, Division of Oral Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Biomaterials Department, Faculty of Oral and Dental Medicine, Modern University for Technology and Information, Cairo, Egypt.
⁴ Department of Cariology and Operative Dentistry, Division of Oral Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Biomimetics Biomaterials Biophotonics Biomechanics & Technology Laboratory, Department of Restorative Dentistry, University of Washington, Seattle, WA, USA.
⁵ Department of Operative Dentistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
⁶ Center of Advanced Medicine for Dental and Oral Diseases, Department for Advanced Dental Research, National Center for Geriatrics and Gerontology, Aichi, Japan.

PMID: 30770133
DOI: 10.1016/j.dental.2019.01.008

Abstract

Objective: The purpose of this study was to detect and investigate the association of enamel microcracks with demineralization at proximal contact areas of premolars, using 3D swept-source optical coherence tomography (SS-OCT).

Methods: Extracted maxillary and mandibular premolars (n=50 each), without any visible tooth cracks, were examined for demineralization of interproximal contact areas, using the International Caries Detection and Assessment System (ICDAS). SS-OCT was used to evaluate demineralization and detect microcracks. Demineralization progression was divided into 4 types by depth: 0 for sound enamel and Type I, II, and III for enamel demineralization penetrating into the outer third, the middle third, and the inner third of the enamel thickness, respectively. Enamel microcracks were classified according to the predominant crack pattern: Type O, no cracks; Type A, subsurface microdefects; Type B, enamel microcrack running along the direction of the enamel prism; Type C, enamel microcrack running transverse to the enamel prism direction; and Type D, a combination of patterns A, B, and C. SS-OCT findings were confirmed by confocal laser scanning microscopy observation.

Results: Microcracks confined within the superficial enamel in proximal contact areas were seen as bright lines on SS-OCT. There were significant positive correlations among ICDAS codes, demineralization levels, and microcrack distribution (p≤0.001). The mesial side of maxillary premolars showed significantly more demineralization (n=36) and microcracks (n=27) than that of the mandibular premolars (n=20 and n=14, respectively; p<0.001).

Significance: The presence of microcracks within the superficial enamel in proximal contact areas could be determined using SS-OCT, and correlated with the level of demineralization. 3D SS-OCT is a valuable diagnostic tool for comprehensive assessment of microstructural changes related to enamel demineralization and crack development.

Keywords: 3D imaging; Demineralization; Enamel; International Caries Detection and Assessment System (ICDAS); Microcrack; Optical coherence tomography; Proximal contact.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Dental Caries*
Dental Enamel
Humans
Microscopy, Confocal
Tomography, Optical Coherence*