Biochemical and structural analysis of hydroxyapatite treated with fluoride and/or sodium trimetaphosphate (TMP) and in vitro demineralization

• Grant number: 11/07788-7
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2011
• End date: April 30, 2014
• Field of knowledge: Health Sciences - Dentistry - Pediatric Dentistry
• Principal Investigator: Alberto Carlos Botazzo Delbem
• Grantee: Alberto Carlos Botazzo Delbem
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil
• Associated researchers: Jackeline Gallo Do Amaral ; João Carlos Silos Moraes

Abstract

The aim of the study will be analyser the effect of sodium trimetaphosphate (TMP) with different concentration associated with different concentrations of fluoride on hydroxyapatite (HA) only when subjected to demineralization and demineralization and remineralization (pH cycling) using X-ray diffraction, Fourier transform infrared spectroscopy and fluoride, calcium and phosphorus analysis in the HA. TMP solutions at concentrations of 0, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0, 2.0, 4.0, 6.0, 8.0 and 10% will be associated to sodium fluoride at concentrations of 0, 100, 250, 500, 1100, 4500, 9000, 12000, 22600 (µg F / g). The hydroxyapatite powder (0.5 g) will be suspense (n=6) in each TMP solutions. After 18 hours (pH 7.0), the suspensions will get slow decrease pH still 4.0 using 1 mol L-1 nitric acid. After 30 minutes, the pH will be rise to 7.0 by adding 1 mol L-1 sodium hydroxyl. The pH-cycling will be repeated 3 times at 37º C. In another situation, the pH of the solutions will only be reduce to 4 with nitric acid 1 mol L-1 during 30 minutes. After demineralization, the precipitate will be filtrated and washed with deionized water five times to remove remaining residues in solution. The precipitate will be dried at 70°C for 24 h and ground into a fine powder (53 µm). After that, the powder will be characterized by the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and analysis of fluoride, calcium and phosphorus. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

AMARAL, JACKELINE G.; PESSAN, JULIANO P.; SOUZA, JOSE ANTONIO S.; MORAES, JOAO CARLOS S.; DELBEM, ALBERTO CARLOS B.. Cyclotriphosphate associated to fluoride increases hydroxyapatite resistance to acid attack. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS, v. 106, n. 7, p. 2553-2564, OCT 2018. (11/07788-7, 11/17234-9)