عنوان مقاله [English]
Hydroxyapatite (HA) and magnesium hydroxyapatite (MgHA) were successfully prepared and its ability to enhance the remineralization of initial enamel lesions was investigated in this study. For this purpose, the nanoparticles were prepared by the wet chemical synthesis. XRD and FTIR were applied to characterize phase structure and chemical species in the prepared samples. The crystallite size and crystallinity index of HA and MgHA samples were 43.88 and 29.59 nm and 46.15 and 26.67% respectively, which were calculated using XRD data and compared with stoichiometric HA sample. SEM was used to investigate the morphology and mean size of the nanoparticles. According to the results of physicochemical characterization, magnesium was detected in the crystal structure of the nanoparticles and nanoparticles of HA with mean particle size of 55.79 nm, MgHA with mean particle size of 39.52 nm were successfully synthesized. In addition, it is revealed that substitution of magnesium in the crystal structure of HA results in the reduction of crystalline and particle sizes, and also, reduce the crystallinity. A pH-cycling regime was used to simulate the dynamic demineralization-remineralization conditions and performance of the prepared materials in enamel remineralization was characterized by surface microhardness (SMH) measurement. Finally, surface of the enamel samples was further characterized by SEM investigations. According to the results of experiments, HA and MgHA can strongly adsorb on the enamel surface and improve the SMH of the substrate due to improvement of the dental remineralization. The improvement of dental remineralization can be attributed to the development of a new biomimetic apatite mineral deposition which progressively fills the surface scratches. According to the results of the present research work, MgHA shows 12% higher remineralization ability compared to that of HA and can be effectively used as remineralization agents in dental hygiene products such as toothpaste, mouthwashes, and oral health compounds.
1. Slavkin, H.C. and B.J. Baum, Relationship of dental and oral pathology to systemic illness. JAMA: the journal of the American Medical Association, 2000. 284(10): p. 1215-1217.
2. Roveri, N., et al., Synthetic biomimetic carbonate-hydroxyapatite nanocrystals for enamel remineralization. Advanced Materials Research, 2008. 47: p. 821-824.
3. Choi, A.L., et al., Developmental fluoride neurotoxicity: a systematic review and meta-analysis. Environmental Health Perspectives, 2012. 120(10): p. 1362.
4. Huang, S., S. Gao, and H. Yu, Effect of nano-hydroxyapatite concentration on remineralization of initial enamel lesion in vitro. Biomedical Materials, 2009. 4(3): p. 034104.
5. Dorozhkin, S.V., Calcium orthophosphates in dentistry. Journal of Materials Science: Materials in Medicine, 2013. 24(6): p. 1335-1363.
6. Hellen, A., Quantitative Evaluation of Simulated Enamel Demineralization and Remineralization Using Photothermal Radiometry and Modulated Luminescence, 2010, University of Toronto.
7. Kwon, H., et al., Combined effects of nano-hydroxyapatite and NaF on remineralization of early caries lesion. Key Engineering Materials, 2007. 330: p. 1347-1350.
8. Tschoppe, P., et al., Enamel and dentine remineralization by nano-hydroxyapatite toothpastes. Journal of dentistry, 2011. 39(6): p. 430-437.
9. Esteves-Oliveira, M., et al., Caries-preventive effect of anti-erosive and nano-hydroxyapatite-containing toothpastes in vitro. Clinical oral investigations, 2017. 21(1): p. 291-300.
10. Park, S.W., et al., The effect of hydroxyapatite on the remineralization of dental fissure sealant. Key Engineering Materials, 2005. 284: p. 35-38.
11. Hornby, K., et al., Enamel benefits of a new hydroxyapatite containing fluoride toothpaste. International Dental Journal, 2009. 59(6S1): p. 325-331.
12. Ishiwata, Y., et al., Zinc and magnesium content in human teeth. Nihon eiseigaku zasshi. Japanese journal of hygiene, 1979. 34(5): p. 697-705.
13. Legfros, R.Z., et al., Magnesium and Carbonate in Enamel and Synthetic Apatites. Advances in Dental Research, 1996. 10(2): p. 225-231.
14. Farzadi, A., et al., Magnesium incorporated hydroxyapatite: Synthesis and structural properties characterization. Ceramics International, 2014. 40(4): p. 6021-6029.
15. Abdallah, M.N., Surface Reactivity of Tooth Enamel with Dyes, Oxidizing
Agents and Magnesium Ions and Its Effect on Tooth Color, in Faculty of Dentistry2013, McGill University: Montreal, Canada. p. 124.
16. Fadeev, I., et al., Synthesis and structure of magnesium-substituted hydroxyapatite. Inorganic Materials, 2003. 39(9): p. 947-950.
17. Stookey, G.K., The Featherstone laboratory pH cycling model: A prospective, multi-site validation exercise. American journal of dentistry, 2011. 24(5): p. 322.
18. Landi, E., et al., Biomimetic Mg-and Mg, CO3 substituted hydroxyapatites: synthesis characterization and in vitro behaviour. Journal of the European Ceramic Society, 2006. 26(13): p. 2593-2601.
19. Suchanek, W.L., et al., Preparation of magnesium-substituted hydroxyapatite powders by the mechanochemical–hydrothermal method. Biomaterials, 2004. 25(19): p. 4647-4657.
20. Kannan, S. and J. Ferreira, Synthesis and thermal stability of hydroxyapatite-β-tricalcium phosphate composites with cosubstituted sodium, magnesium, and fluorine. Chemistry of materials, 2006. 18(1): p. 198-203.
21. Gawda, H., L. Sekowski, and H. Trebacz, In vitro examination of human teeth using ultrasound and X-ray diffraction. Acta of Bioengineering and Biomechanics, 2004. 6(1): p. 41-50.
22. Venkatasubbu, G.D., et al., Nanocrystalline hydroxyapatite and zinc-doped hydroxyapatite as carrier material for controlled delivery of ciprofloxacin. 3 Biotech, 2011. 1(3): p. 173-186.
23. Pang, Y. and X. Bao, Influence of temperature, ripening time and calcination on the morphology and crystallinity of hydroxyapatite nanoparticles. Journal of the European Ceramic Society, 2003. 23(10): p. 1697-1704.
24. Zhai, Y., F. Cui, and Y. Wang, Formation of nano-hydroxyapatite on recombinant human-like collagen fibrils. Current Applied Physics, 2005. 5(5): p. 429-432.
25. Koutsopoulos, S., Synthesis and characterization of hydroxyapatite crystals: a review study on the analytical methods. Journal of biomedical materials research, 2002. 62(4): p. 600-612.
26. Kolmas, J., et al., Incorporation of carbonate and magnesium ions into synthetic hydroxyapatite: the effect on physicochemical properties. Journal of Molecular Structure, 2011. 987(1): p. 40-50.
27. Salimi, M.N., et al., Effect of processing conditions on the formation of hydroxyapatite nanoparticles. Powder Technology, 2012. 218: p. 109-118.
28. Elena Landi, A.T., Monica Mattioli-Belmonte, Giancarlo Celotti, Monica Sandri, Antonio Gigante, Paola Fava, Graziella Biagini, Biomimetic Mg- and Mg,CO3-substituted hydroxyapatites: synthesis characterization and in vitro behaviour. Journal of the European Ceramic Society, 2006. 26: p. 2593–2601.
29. Feagin, F., T. Koulourides, and W. Pigman, The characterization of enamel surface demineralization, remineralization, and associated hardness changes in human and bovine material. Archives of oral biology, 1969. 14(12): p. 1407-1417.
30. Spencer, P., et al., Incorporation of magnesium into rat dental enamel and its influence on crystallization. Archives of oral biology, 1989. 34(10): p. 767-771.
31. LeGeros, R.Z., J.A. Piliero, and L. Pentel, Comparative properties of deciduous and permanent (young and old) human enamel1. Gerodontology, 1983. 2(1): p. 1-8.