Uptake of fluoride ions by the glass component of glass ionomer cement

Autor: Richard William Billington, G J Pearson, Jill Ann Williams
Rok vydání: 2007
Předmět:
Zdroj: Journal of Dentistry. 35:452-455
ISSN: 0300-5712
Popis: Objectives The uptake of F − ions by glass ionomer cement (GIC) has been extensively studied but the precise location of the F − ion in the GIC structure has not been reported. The aim of this study is to use model materials to elucidate the possible locations. GIC consists of residual particles of aluminosilicate glass surrounded by depleted glass in an ionically crosslinked polymeric matrix. This study evaluates uptake by both unreacted glass particles (RAW) and particles acid-treated to produce a depleted glass surface (DEPLETED). Method Three glasses, previously studied as cements, were tested at the particle size used in GICs. LG30 contained Al, Ca, O, P, and Si; LG26 also contained F and AH2 contained Na as well. To produce depleted surfaces they were immersed in acetic acid washed and dried at room temperature. Test samples ( N = 5) were immersed in KF solution (900 ppm F). Control solutions without glass were used. Both were stored at 37C for 48 h. F concentrations were measured using ISE with TISAB IV. Results Uptake was Control–test expressed in μmol/g glass. RAW LG30 = 56 (16); LG26 = 35(17); AH2 = 17(31). DEPLETED LG30 = 285(41); LG26 = 431(42); AH2 = 286(50). The levels of F uptake by DEPLETED were comparable to those found with GICs formed with these glasses. Conclusions The glass particles of GIC, and particularly the depleted zones surrounding them, can account for an appreciable amount of the F uptake observed with cements but do not show the same relation between F content and F uptake previously observed with cements.
Databáze: OpenAIRE
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