In vitro comparison of solubility of resin modified glass ionomer and a base containing hydroxyapatite in water, acid and artificial saliva

Solubility is one of the shortcomings of dental materials that causes decreased physical and mechanical properties and longevity of the restoration. The aim of this in vitro study was to compare the solubility of the resin modified glass ionomer cement and a base containing hydroxyapatite. This experimental study was carried out according to ISO4049:2000(E) and ISO 9917-1:2007(E). Ten samples of each of the two materials including resin modified glass ionomer and a base containing hydroxyapatite were evaluated for solubility in distilled water and artificial saliva. Evaluation of acid solubility was performed in lactic acid with pH=2.7±0.02 for 24 hrs. The data were analyzed by two-way ANOVA test. The mean values of solubility in distilled water for RMGIC and base containing hydroxyapatite were 0.6 (±0.3) and -1.6 (±1.4), respectively. The means of saliva solubility were 0.007 (±0.8) and 1.07 (±1.4), respectively for the mentioned materials. The mean value of acid solubility was 0.000474 (±0.000784)for RMGIC and 0.000334 (±0.000221) for Lime-lite. There was no significant difference between values of water sorption and solubility of the two materials (p>0.05). The solubility of the two tested materials in distilled water, artificial saliva and acid was very little and there was no significant difference between them in this regard.