SPECTRAL CHARACTERISTICS OF DENTAL HARD TISSUES AND THEIR CLINICAL RELEVANCE

Raman spectroscopy is a molecular specific technique which can be used to develop a fundamental biochemical understanding of tissue physiology and pathology. This method is non-invasive and nondestructive: it utilizes a monochromatic light source to determine sample chemical composition. Raman spectroscopy has become widely used in different fields of medicine, including dentistry. The aim of the study is to assess the spectral characteristics (Raman fluorescent components) of dental hard tissues and to evaluate the usability of the method for the assessment of mineralization of dental hard tissues. In the in vitro study, Raman-fluorescent spectroscopy of teeth (incisors, premolars, molars) extracted due to clinical indications was performed. The results of the preliminary study confirmed the advantages of using wet samples for the evaluation, as it allowed to increase the sensitivity of Raman spectroscopy. Therefore, all the teeth used were kept for 30 minutes in deionized water prior to the experiment. Laser spectroscopic complex " InSpectr M" (Russia) with 514 nm wavelength was used. A qualitative and quantitative assessment of the content and distribution of hydroxyapatite in sound and demineralized dental hard tissues (enamel, dentin, cement) was performed. According to our results, for all groups the content of hydroxyapatite in enamel, as a more mineralized tissue, was higher, than that in dentin, cement and enamel carious lesions. High sensitivity and rapidity of the method as well as the possibility to quantitatively assess the spectroscopic results were revealed. That allows using Raman spectroscopy in the assessment of mineralization and remineralization of dental hard tissues, effectiveness of remineralizing medications and algorithms of their use in clinical practice.