title: Effect of trimetaphosphate and fluoride association on hydroxyapatite dissolution and precipitation in vitro.
abstract: The present study analyzed the action of sodium trimetaphosphate (TMP) and/or fluoride on hydroxyapatite. Hydroxyapatite powder was suspended in different solutions: deionized water, 500 µg F/mL, 1,100 µg F/mL, 1%TMP, 3%TMP, 500 µg F/mL plus 1%TMP and 500 µg F/mL plus 3%TMP. The pH value of the solutions was reduced to 4.0 and after 30 min, raised to 7.0 (three times). After pH-cycling, the samples were analyzed by X-ray diffraction and infrared spectroscopy. The concentrations of calcium fluoride, fluoride, calcium and phosphorus were also determined. Adding 1% or 3% TMP to the solution containing 500 µg F/mL produced a higher quantity of calcium fluoride compared to samples prepared in a 1,100 µg F/mL solution. Regarding the calcium concentration, samples prepared in solutions of 1,100 µg F/mL and 500 µg F/mL plus TMP were statistically similar and showed higher values. Using solutions of 1,100 µg F/mL and 500 µg F/mL plus TMP resulted in a calcium/phosphorus ratio close to that of hydroxyapatite. It is concluded that the association of TMP and fluoride favored the precipitation of a more stable hydroxyapatite.
authors.affiliation: Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, SP, Brazil.
authors.forename: Alberto Carlos Botazzo
authors.initials: AC
authors.lastname: Delbem
authors.affiliation: Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, SP, Brazil.
authors.forename: José Antonio Santos
authors.initials: JA
authors.lastname: Souza
authors.affiliation: Dental School, Paranaense University, Umuarama, PR, Brazil.
authors.forename: Ana Carolina Soares Fraga
authors.initials: AC
authors.lastname: Zaze
authors.affiliation: Dental School, UFS - Federal University of Sergipe, São Cristovão, SE, Brazil.
authors.forename: Eliana Mitsue
authors.initials: EM
authors.lastname: Takeshita
authors.affiliation: Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, SP, Brazil.
authors.forename: Kikue Takebayashi
authors.initials: KT
authors.lastname: Sassaki
authors.affiliation: Engeneering School, UNESP - Univ Estadual Paulista, Ilha Solteira, SP, Brazil.
authors.forename: João Carlos Silos
authors.initials: JC
authors.lastname: Moraes
mesh_terms: D002118:Calcium / Q000032:analysis; D002327:Cariostatic Agents / Q000737:chemistry*; D011232:Chemical Precipitation; D003460:Crystallization; D017886:Durapatite / Q000032:analysis / Q000737:chemistry*; D005459:Fluorides / Q000032:analysis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008422:Materials Testing; D010758:Phosphorus / Q000032:analysis / Q000737:chemistry*; D011122:Polyphosphates / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D002327:Cariostatic Agents; D011122:Polyphosphates; D010758:Phosphorus; D017886:Durapatite; C009293:trimetaphosphoric acid; D005459:Fluorides; D002118:Calcium