XRF analysis of tooth enamel under conditions of experimental erosion in vitro

INTRODUCTION. Dental erosion is a result of chemical processes – specifically, “acid attacks” on the tooth surface that occur without bacterial involvement – leading to alterations in the mineral structure of dental tissues. In recent years, the erosive potential of fruit juices, carbonated and non-carbonated soft drinks, as well as alcoholic beverages, has been actively studied in an effort to better understand the mechanisms of demineralization and to assess the impact of drink acidity. However, there is a lack of data on experiments that provide a comprehensive profile of macro- and microelement content in erosion zones of varying severity compared to intact enamel and dentin.

AIM. To examine, using X-ray fluorescence analysis, the dynamics of changes in the calcium-to-phosphorus (Ca/P) ratio–an important indicator of tooth mineral content–under conditions of artificial erosion caused by various acidic food and beverage solutions.

MATERIALS AND METHODS. The exogenous acidic agents used included solutions of lactic, acetic, and hydrochloric acids; lemon juice; dry red wine; Dobry Cola; and a solution of Acidin-Pepsin tablets (a drug prescribed for hypoacid and anacid gastritis). Recently extracted intact teeth were immersed in the test liquids for three days. Demineralization was assessed based on observed changes in elemental composition. The chemical analysis of the solid dental tissues was performed using an M4 TORNADO X-ray fluorescence spectrometer (Bruker).

RESULTS. In all test conditions, demineralization occurred as evidenced by the active release of calcium and phosphorus – the main macroelements – from the crystal lattices of hydroxyapatite, carbonate apatite, chlorapatite, fluorapatite, and other mixed apatite forms found in enamel. Notably, the kinetics of calcium and phosphorus loss differed significantly. In all cases, the Ca/P ratio increased substantially after three days of exposure to the erosive medium, compared to baseline values in intact enamel. This finding indicates that phosphate groups are the first to be lost during erosion, dissolving into the oral environment, followed by calcium loss as a less intense secondary process.

CONCLUSIONS. Based on analysis of Ca/P ratios, enamel erosion appears to begin with dephosphorylation of the crystalline lattice, followed by decalcification.

1. Krikheli N.I., Pustovojt E.V., Darsigova Z.T., Arakelyan I.R., Sampiev A.T. Exogenous and endogenous factors affecting the development of dental erosion. Clinical Dentistry (Russia). 2023;26(1):18–22. (In Russ.) https://doi.org/10.37988/1811-153X_2023_1_18

2. Aydemirova M.A., Petrova A.P. Clinical aspects of tooth erosion. Bulletin of Medical Internet Conferences. 2016;6(6):1094–1097. (In Russ.)

3. Mitronin A.V. Volodina E.V., Kuvaeva M.N. Impaired development and teething: non-carious lesions of hard dental tissues. Moscow: GEOTAR-Media; 2021. (In Russ.)

4. Manaf Z.A., Lee M.T., Ali N.H., Samynathan S., Jie Y.P., Ismail N.H. et al. Relationship between food habits and tooth erosion occurrence in Malaysian University students. Malays J Med Sci. 2012;19(2):56–66.

5. Fulova A.M., Ryazantseva P.A., Ostanina D.A., Mitronin A.V., Baitokova A.D. Analysis of dental morbidity of employees of a chemical enterprise. Endodontics Today. 2024;22(4):436–441. (In Russ.) https://doi.org/10.36377/ET-0060

6. Maltarollo T.H., Pedron I.G., Medeiros J.M.F., Kubo H., Martins J.L., Shitsuka C. The dental erosion is a problem! Research, Society and Development. 2020;9(3):e168932723. (Portuguese) https://doi.org/10.33448/rsd-v9i3.2723

7. Fulova A.M., Ostanina D.A., Mitronin A.V. Analysis of risk factors for the development of dental erosion (systematic review). Cathedra. Dental Education. 2024;(89):16–19. (In Russ.)

8. Lopes N., Pereira M.L., Salgado H., Afonso A., Mesquita P. In vitro evaluation of the effect of soft drinks on dental erosion. Rev Port Estomatol Med Dent Cir Maxilofac. 2017;58(3):139–145. https://doi.org/10.24873/j.rpemd.2017.10.024

9. Inchingolo A.M., Malcangi G., Ferrante L., Del Vecchio G., Viapiano F., Mancini A. et al. Damage from carbonated soft drinks on enamel: A systematic review. Nutrients. 2023;15(7):1785. https://doi.org/10.3390/nu15071785

10. Carvalho T.S., Baumann T., Lussi A. Does erosion progress differently on teeth already presenting clinical signs of erosive tooth wear than on sound teeth? An in vitro pilot trial. BMC Oral Health. 2016;17(1):14. https://doi.org/10.1186/s12903-016-0231-y

11. Né Y.G.S., Souza-Monteiro D., Frazão D.R., Alvarenga M.O.P., Aragão W.A.B., Fagundes N.F. et al. Treatment for dental erosion: a systematic review of in vitro studies. PeerJ. 2022;10:e13864. https://doi.org/10.7717/peerj.13864

12. Mitronin A.V., Darsigova Z.T., Prokopov A.A., Dashkova O.P., Alikhanyan A.S. Assessment of dental enamel elemental indices in tooth erosion according to the data of the X-Ray fluorescence analysis. International Dental Review. 2017;(4):6–10. (In Russ.)

13. Mitronin A.V., Darsigova Z.T., Alikhanyan A.S., Prokopov A.A., Dashkova O.P. X-ray fluorescence analysis of the normal teeth enamel and in case of erosion. Endodontics Today. 2017;15(3):7–13. (In Russ.) Available at: https://www.endodont.ru/jour/article/view/76 (accessed: 13.06.2025).

14. Leontiev V.K. Dental enamel as a biocybernetic system. Moscow: GEOTAR-Media; 2016. 72 p. (In Russ.)

15. Mitronin A.V., Prokopov A.A., Darsigova Z.T., Alikhanian A.S., Gokzhaev M.B., Dashkova O.P. X-ray fluorescence analysis of dental hard tissues in the early stages of erosive lesions. Cathedra. Dental Education. 2020;71:22–27. (In Russ.)

16. Qutieshat A.S., Mason A.G., Chadwick R.G. In vitro simulation of erosive challenges to human enamel using a novel artificial mouth. Clin Exp Dent Res. 2018;4(4):105–112. https://doi.org/10.1002/cre2.111