Next Article in Journal
A New Mixture Refrigerant for Space Heating Air Source Heat Pump: Theoretical Modelling and Performance Analysis
Previous Article in Journal
Ensemble Classification of Data Streams Based on Attribute Reduction and a Sliding Window
Previous Article in Special Issue
Wavefront Shaping and Its Application to Enhance Photoacoustic Imaging
Article Menu
Issue 4 (April) cover image

Export Article

Open AccessArticle
Appl. Sci. 2018, 8(4), 621;

A Feasibility Study of Photoacoustic Detection of Hidden Dental Caries Using a Fiber-Based Imaging System

Graduate School of Biomedical Engineering, Tohoku University, 6-6-05 Aoba, Sendai 980-8579, Japan
Department of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8510, Japan
Author to whom correspondence should be addressed.
Received: 9 March 2018 / Revised: 8 April 2018 / Accepted: 13 April 2018 / Published: 17 April 2018
(This article belongs to the Special Issue Biomedical Photoacoustic and Thermoacoustic Imaging)
Full-Text   |   PDF [30162 KB, uploaded 3 May 2018]   |  


In this paper, the feasibility of an optical fiber-based photoacoustic imaging system for detecting caries lesions inside a tooth is examined. Models of hidden caries were prepared using a pigment with an absorption spectrum similar to that of real caries lesions, and the occlusal surface of the model teeth containing the pigment was irradiated with laser pulses with a wavelength of 532 nm. An examination of the frequency spectra of the emitted photoacoustic waves revealed that the spectra from simulated caries lesions included frequency components in the range of 0.5–1.2 MHz that were not seen in the spectra from healthy parts of the teeth. This indicates that hidden caries can be detected via a photoacoustic imaging technique. Accordingly, an imaging system for clinical applications was fabricated. It consists of a bundle of hollow-optical fibers for laser radiation and an acoustic probe that is attached to the tooth surface. Results of ex vivo imaging experiments using model teeth and an extracted tooth with hidden caries lesions show that relatively large caries lesions inside teeth that are not seen in visual inspections can be detected by focusing on the above frequency components of the photoacoustic waves. View Full-Text
Keywords: photoacoustic imaging; hidden caries; hollow-optical fiber photoacoustic imaging; hidden caries; hollow-optical fiber

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Koyama, T.; Kakino, S.; Matsuura, Y. A Feasibility Study of Photoacoustic Detection of Hidden Dental Caries Using a Fiber-Based Imaging System. Appl. Sci. 2018, 8, 621.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Appl. Sci. EISSN 2076-3417 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top