Improving Dental Caries Detection by Optimizing Source-Detector Localization Using Laser Diffuse Reflectance

Abstract

In this work, a laser scattering method was used for measuring the optical properties of dental caries using He-Ne laser. A spectrometer setup was built to test the optical characteristics of the molar tooth decay. The measurements yield the reflectance, absorbance and the transmittance of sound and decayed tooth. Monte-Carlo simulation was used to investigate and provide further analysis of the resultant measurements of the spectrometer. The results differentiate between sound and caries and enable to predict the exact localization of source-detector pair relative to the examined tooth, in order to help in performing optical imaging for in-vivo early detection of caries.

Monte Carlo Simulation of Diffuse Optical Spectroscopy for 3D Modeling of Dental Tissues

“…The reflectance mode involved placing source-detector separations (SDSs) at three distinct distances, namely 250 µm, 750 µm, and 1.5 mm. Commercial DOS systems used in dental detection use various probe sizes such as 50 µm, 100 µm, 200 µm, and 400 µm [17,30]. While smaller probe sizes are suitable to detect very fine details and small irregularities, larger probe sizes are typically used for initial screenings.…”

“…This article presented a MC model that can aid in evaluating the performance of DOS systems used for dentistry applications operating at 633 nm and 1310 nm wavelengths in both reflectance and transmittance modes. Unlike prior tooth models [11,17], the newly developed model accurately represents the geometry of a second molar tooth and is designed with meshed-based structures for dental tissues such as enamel, dentin, and pulp regions. This precise geometry allows for more reliable and accurate results.…”

“…Their results showed that the OCT signal decreases significantly with increasing mineral loss and the best focus position was located below and close to the enamel region. Gawad et al [17] in 2017 used a MC model to simulate a laser diffuse reflectance setup for identifying the optimum wavelength as well as SDS position to achieve the highest detected signal. They found that red light with a wavelength of 635 nm is likely the most secure visual color to use in the oral cavity.…”

“…The main contributions of this paper can be summarized as follows: (1) unlike previous work, this research primarily provides a novel and realistic mesh-based approach for modeling 3D molar tooth geometry using MC modeling for DOS systems operating at 633 nm and 1310 nm wavelengths. This approach has the potential to offer more precise results compared to the homogeneous and monolayer approaches commonly employed for teeth models [11,17]; (2) the effect of reflection at boundaries on DOS systems in both reflectance and transmittance geometries have been investigated at 633 nm and 1310 nm. By simulating the optical properties of teeth at these wavelengths, researchers and clinicians can gain insights into the interactions between light and dental tissues, optimize the design of optical devices for dental imaging and diagnostics, and improve the accuracy and effectiveness of dental treatments.…”