COMPARISON OF SOLUBILITY OF ZINC PHOSPHATE AND GLASS IONOMER CEMENT IN ARTIFICIAL SALIVA OF VARYING pH VALUES

The aim of this study was to compare the solubility of Zinc Phosphate and Glass Ionomer cements (conventional) in artificial saliva of different pH values. These cements are commonly used for permanent cementation of indirect restorations in dental practice at Peshawar, Pakistan and have to resist the harsh environment of oral cavity. The study was carried out at National Center of Excellence in Physical Chemistry, University of Peshawar, Pakistan. Both cements were mixed per manufacturer’s directives to achieve excellent properties while using these as luting material. A total of 100 specimens were made for each dental cement and weighed prior to placement in pH medium of 2.46, 3.15, 3.56, 4.96 and 6.57 for 96 hours at 37oC temperature. After removal specimens were washed with doubly distilled water, dried in open air for 48 hours and reweighed. Percentage of solubility at each time period was calculated as 100 percent times weight loss divided by the initial weight of the specimen. It was found that the glass ionomer cement presented the highest solubility at low pH medium but was less soluble at high pH medium.