CC BY
3The 30th International Conference on Advanced Laser Technologies B-O-14
ALT'23
Diagnosing diseases in dentistry using Raman spectroscopy
P.E. Timchenko1, E.V. Timchenko1, L.T. Volova2, I.V. Bazhutova2, O.O. Frolov1
1- Samara National Research University, Russia, Samara 2- Samara State Medical University, Russia, Samara
Main author email address: _ [email protected]
Among the optical methods for studying biological tissues, the method of Raman spectroscopy is widely used in solving biomedical problems. This method can also be used to diagnose diseases and assess the course of the disease.
The main method of analysis was the Raman spectroscopy method implemented by the experimental stand that included Raman probe RPB-785, combined with the laser module Luxx Master LML-785.0RB-04 and the high-resolution digital spectrometer Shamrock sr-303i providing spectral resolution of 0,15 nm with the build in cooling camera DV420A-OE.
The spectra were normalized using the Extended multiplicative signal correction (EMSC) method [1]. Smoothing method - Maximum Likelihood Estimation Savitzky-Golay filter (MLE-SG) [2] with the parameter o = 4.
To eliminate the contribution of autofluorescence in the Raman spectrum, was used a modified method of subtracting the fluorescence component by polynomial approximation Improved Modified Multi-Polynomial Fitting (I-ModPoly+) with a polynomial degree of 9.
To increase the information content of the obtained Raman spectra, we decomposed into the sum of spectral asymmetric Pseudo Voigt lines
- The possibility of using the method of Raman spectroscopy for non-invasive express evaluation of the effectiveness of treatment in periodontitis by changing the spectra of dental cement is shown. The obtained results of the research will contribute to the adjustment of the treatment of patients with periodontitis and the exclusion of ineffective stages of the complex treatment of inflammatory periodontal
diseases in dental practice.
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Ramari shift, cm1
Fig. 1. Averaged Raman spectra of individual samples: 1 - normal bone tissue, 2 - bone tissue with periodontitis
It has been shown that the spectral characteristics of bone tissue samples in periodontitis differ significantly from the characteristics of the normal bone tissue spectra (fig.1). The greatest difference is seen in the Raman lines ~1741 (C=O ester group, phospholipids (Lipid assignment)), ~1419, 1443 cm1 (CH2 deformation), ~1387 (CH3 band), 1403 (Bending modes of methyl groups (one of vibrational modes of collagen)). Also, the spectra of group 2 (with periodontitis) are distinguished by the presence of a pronounced line ~1318 cm-1 Amide III (a-helix).
The cross-validated accuracy of the classifying model based on logistic regression was 84 ± 9%.
[1] N.K. Afseth, A. Kohler, Extended multiplicative signal correction in vibrational spectroscopy, a tutorial, Chemometrics and Intelligent Laboratory Systems, 117., pp. 92-99, (2012).
[2] T, E. Ward, and B.M. Hennelly, Algorithm for optimal denoising of Raman spectra, Analytical Methods, 10.30, pp. 3759-3769 (2018).
