University of Oulu

Analyst, 2021,146, 1705-1713,

Mineralization of dental tissues and caries lesions detailed with Raman microspectroscopic imaging

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Author: Das Gupta, Shuvashis1; Killenberger, Markus2; Tanner, Tarja2,3;
Organizations: 1Research Unit of Medical Imaging, Physics and Technology, University of Oulu, 90220 Oulu, Finland
2Research Unit of Oral Health Sciences, Department of Cariology, Endodontology and Pediatric Dentistry, University of Oulu, 90220 Oulu, Finland
3Medical Research Center, Oulu University Hospital and University of Oulu, 90220 Oulu, Finland
4Department of Diagnostic Radiology, Oulu University Hospital, 90220 Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 4.3 MB)
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Language: English
Published: Royal Society of Chemistry, 2021
Publish Date: 2021-05-18


Dental caries is the most common oral disease that causes demineralization of the enamel and later of the dentin. Depth-wise assessment of the demineralization process could be used to help in treatment planning. In this study, we aimed to provide baseline information for the development of a Raman probe by characterizing the mineral composition of the dental tissues from large composition maps (6 × 3 mm² with 15 μm step size) using Raman microspectroscopy. Ten human wisdom teeth with different stages of dental caries lesions were examined. All of the teeth were cut in half at representative locations of the caries lesions and then imaged with a Raman imaging microscope. The pre-processed spectral maps were combined into a single data matrix, and the spectra of the enamel, dentin, and caries were identified by K-means cluster analysis. Our results showed that unsupervised identification of dental caries is possible with the K-means clustering. The compositional analysis revealed that the carious lesions are less mineralized than the healthy enamel, and when the lesions extend into the dentin, they are even less mineralized. Furthermore, there were more carbonate imperfections in the mineral crystal lattice of the caries tissues than in healthy tissues. Interestingly, we observed gradients in the sound enamel showing higher mineralization and greater mineral crystal perfection towards the tooth surface. To conclude, our results provide a baseline for the methodological development aimed at clinical diagnostics for the early detection of active caries lesions.

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Series: Analyst
ISSN: 0003-2654
ISSN-E: 1364-5528
ISSN-L: 0003-2654
Volume: 146
Issue: 5
Pages: 1705 - 1713
DOI: 10.1039/d0an01938k
Type of Publication: A1 Journal article – refereed
Field of Science: 313 Dentistry
318 Medical biotechnology
Funding: This work was supported by funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 713645.
EU Grant Number: (713645) BioMEP - Biomedical Engineering and Medical Physics
Copyright information: © The Royal Society of Chemistry 2021. This Open Access Article is licensed under a Creative Commons Attribution-Non Commercial 3.0 Unported Licence.