Laboratoire Bioingénierie et Nanosciences, Université de Montpellier, Montpellier, France.
Laboratoire Anthropologie bio-culturelle, droit, éthique et santé, UMR 7268 CNRS-Université d'Aix-Marseille, Marseille, France.
Caries Res. 2018;52(5):359-366. doi: 10.1159/000486428. Epub 2018 Mar 6.
Dentin carious lesion is a dynamic process that involves demineralization and collagen denaturation. Collagen type I is the major protein in dentin and it has been investigated based on its optical properties. Multiphoton microscopy (MPM) is a nonlinear imaging technique that reveals the caries process using the collagen two-photon excitation fluorescence (2PEF) and its second-harmonic generation (SHG). Combining the histological and the International Caries Detection and Assessment System (ICDAS) classifications with nonlinear optical spectroscopy (NLOS), 2PEF and SHG intensities of enamel and dentin were highly altered during the caries process. It has been proven that the ratio SHG/2PEF is a relevant indicator of the organic matrix denaturation [Terrer et al.: J Dent Res 2016; 96: 574-579]. In the present study, a series of measurable signals is made to detect early stages of carious lesion according to the ICDAS classification and to explore the relationship between these measures and the ICDAS scale. Comparison of the efficiency of nonlinear optical signals for caries detection with the ICDAS classification is essential to evaluate their potential for clinical application. In our study, the use of the NLOS measured by MPM allowed us to monitor a quantitative parameter (SHG/2PEF ratio) according to the dentin carious lesion state (ICDAS and histological examination). Three coherent new groups were defined (ICDAS 0/1; ICDAS 2/3; ICDAS 4/5/6), where the carious process can be clearly described with a statistically significant decrease of the SHG/2PEF ratio.
牙本质龋损是一个涉及脱矿和胶原变性的动态过程。胶原 I 型是牙本质中的主要蛋白质，已经基于其光学性质进行了研究。多光子显微镜（MPM）是一种非线性成像技术，它利用胶原的双光子激发荧光（2PEF）和二次谐波产生（SHG）来揭示龋病过程。将组织学和国际龋病检测和评估系统（ICDAS）分类与非线性光学光谱（NLOS）相结合，在龋病过程中，牙釉质和牙本质的 2PEF 和 SHG 强度发生了高度变化。已经证明，SHG/2PEF 的比值是有机基质变性的一个相关指标[Terrer 等人：J Dent Res 2016; 96: 574-579]。在本研究中，根据 ICDAS 分类制作了一系列可测量的信号，以检测龋病的早期阶段，并探讨这些测量值与 ICDAS 量表之间的关系。比较非线性光学信号对龋病检测的效率与 ICDAS 分类对于评估其临床应用潜力至关重要。在我们的研究中，使用 MPM 测量的 NLOS 使我们能够根据牙本质龋损状态（ICDAS 和组织学检查）监测一个定量参数（SHG/2PEF 比值）。定义了三个连贯的新组（ICDAS 0/1；ICDAS 2/3；ICDAS 4/5/6），其中可以用统计学上显著降低的 SHG/2PEF 比值清楚地描述龋病过程。
