title: Phase transformations in a human tooth tissue at the initial stage of caries.
abstract: The aim of the paper is to study phase transformations in solid tissues of the human teeth during the development of fissure caries by Raman and fluorescence microspectroscopy. The study of the areas with fissure caries confirmed the assumption of the formation of a weak interaction between phosphate apatite enamel and organic acids (products of microorganisms). The experimental results obtained with by Raman microspectroscopy showed the formation of dicalcium phosphate dihydrate - CaHPO4-2H2O in the area of mural demineralization of carious fissure. A comparative analysis of structural and spectroscopic data for the intact and carious enamel shows that emergence of a more soluble phase - carbonate-substituted hydroxyapatite - is typical for the initial stage of caries. It is shown that microareas of dental hard tissues in the carious fissure due to an emerging misorientation of apatite crystals have a higher fluorescence yield than the area of the intact enamel. These areas can be easily detected even prior to a deep demineralization (white spot stage) for the case of irreversibly changed organomineral complex and intensive removal of the mineral component.
authors.affiliation: Department of Solid State Physics and Nanostructures, Voronezh State University, Voronezh, Russia.
authors.forename: Pavel
authors.initials: P
authors.lastname: Seredin
authors.affiliation: Department of Solid State Physics and Nanostructures, Voronezh State University, Voronezh, Russia.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Goloshchapov
authors.affiliation: Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Prutskij
authors.affiliation: Department of Preventive Dentistry, Voronezh State Medical Academy, Voronezh, Russia.
authors.forename: Yury
authors.initials: Y
authors.lastname: Ippolitov
mesh_terms: D000293:Adolescent; D000328:Adult; D001641:Bicuspid / Q000737:chemistry* / Q000473:pathology; D002130:Calcium Phosphates / Q000737:chemistry*; D003731:Dental Caries / Q000175:diagnosis* / Q000473:pathology; D003743:Dental Enamel / Q000737:chemistry* / Q000473:pathology; D018450:Disease Progression; D017886:Durapatite / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D008963:Molar / Q000737:chemistry* / Q000473:pathology; D013050:Spectrometry, Fluorescence; D013059:Spectrum Analysis, Raman; D014081:Tooth Extraction
chemical_list: D002130:Calcium Phosphates; D017886:Durapatite; C494366:calcium phosphate, dibasic, dihydrate