Mineral ionomer cements

Table 5.4. Properties of mineral ionomer cements Crisp et al., 1979 Hornsby et al., 1982)... 

Studies of the interaction of hydroxyapatite with the acid washings from glass-ionomer cements show that fluoride is taken up readily by the mineral phase, despite the initial state of fluoride as a complex ion or covalent species [106]. There was no concomitant uptake of aluminium by the hydroxyapatite, suggesting that any complexes formed are dissociated by the mineral phase, allowing only fluoride to be taken up. 

From the and T MAS-NMR spectra, it was apparent that the adjunct filler was substantially hydroxyapatite rather than fluorapatite. The diminution in the P peak due to orthophosphate was taken to indicate that this apatite filler was undergoing a reaction with the polymeric acid, and contributing to setting. This reaction has not been observed previously when synthetic hydroxyapatite was included in a conventional glass-ionomer cement [7], though reaction of poly(acryUc acid) with other calcium phosphate minerals has been observed previously [25]. 

Ihe quest for interactive or bioactive dental restorative materials is not a totally new endeavor in dental materials. For example, as a general concept, glass ionomer cements (GICs) have been endorsed as a bioactive material because of their dynamic release of fluoride, as well as their unique mineral-based poly-salt matrix composition that is claimed to also contribute to the ability to remineralize calcium-depleted tooth structure. The continuous release of fluoride by GICs and resin-modified glass ionomers (RMGIs) has also been positioned as a potential mechanism to delay or inhibit secondary caries at teeth restored with these materials at the margins of the restorations [47,48]. 

Compound changes and tooth mineralization effects of glass ionomer cements containing bioactive glass (S53P4), an in vivo study. Eiomaterials, 26(30), 5934-41. 

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