Effect of monovalent ions in glass ionomer on their uptake and re-release

Ion processes in glass ionomer cements

“…7 Potassium added as a component of the mixing solution (which should place all the cation in the matrix) 45,46 shows release data having a best fit relationship with t 1/2 . Sodium, added as a solid 34 (NaF) had release data not dependent on t 1/2 or t, seeming to agree with the work by Hadley et al 33 In the same study, 34 calcium (from CaF 2 ) was not measured but fluoride release was not enhanced by addition of this compound, known to be extremely insoluble, therefore it might be assumed that calcium was not released either. This may be a contentious point since both calcium and fluoride were said to be released from a glass ionomer cement 43,47 over a period of 122 days for Ketac-Fil and for at least 6 weeks for LG26 glass respectively.…”

“…CaF 2 is very insoluble and its addition to an F-free GIC produces no additional F release 34 , whereas, all the F taken up by this GIC is re-released. 33 In contrast, K + , which is taken up in similar amount to F À is not concentrated at the surface. 67,68 This difference in location may account to the slower re-release of K as contrasted to F. 45 Uptake of ions with valencies higher than one have only been reported infrequently.…”

“…This is not the case for all monovalent cations although less information is available. [42][43][44] Sodium release was said not to be related to t 1/2 42 from a glass ionomer cement containing sodium and analysis of data from another study 33 for the two glass ionomers, Ketac-Fil and Ketac-Silver, agrees with this. Although Na release from a cement based on G338 32 has a strong association with t 1/2 (r 2 = 0.98), compared with other elements, the Na appears to deviate from t 1/2 (Fig.…”

“…Neither level is trivial since at 3 weeks, G338 cement had released only 1.4 mg/g 32 and after 14 weeks LG26 had released only 53 mmol/g = 1 mg/g. 33 Further, after 27 days LG30 containing NaF has only released 0.015 mg/g. 34 Acidic water was found to increase the amount of soluble F À ion which could be washed from the glass.…”

Glass ionomer cement: evidence pointing to fluorine release in the form of monofluorophosphate in addition to fluoride ion

“…The three glass ionomer cements in this study have been described previously [12]. All three contain the same proportions of glass: polyacrylic acid, tartaric acid and water.…”