A preliminary study of the effect of glass-ionomer and related dental cements on the pH of lactic acid storage solutions.

Glass-ionomer cements, both self-hardening and resin-modified, have been shown to increase the pH of lactic acid solutions in which they are stored. Similar results have been obtained for a zinc phosphate and a zinc polycarboxylate cement. The pH was increased over a period of 7 days by between 1.54 and 2.65 pH units from an initial value of pH of 2.60, depending on the cement. It is concluded that, as a result of this ability to neutralize surrounding aqueous solutions, these materials may have the beneficial effect in vivo of inhibiting caries development. In the case of glass-ionomers, this mechanism might complement that of fluoride release.