Calcium hydroxide pastes : pH values and release of calcium ions

Abstract

Aim: to evaluate the release of calcium ions and the pH of three calcium hydroxide pastes: UltraCal XS, Calcicur and an aqueous calcium hydroxide paste. Methodology: the analysis of calcium in the pastes under study was conducted by atomic absorption spectrophotometry. A pH-meter was used for pH readings. Measurements of pH and release of calcium ions were made at 1 hour and at 1, 3, 7, 15, 30, 45, 60 days. Results: the analysis of baseline values, minimum and maximum values, and the difference between final and baseline values revelead significant differences in pH and calcium release between the three pastes. The greatest pH and calcium release values were found for the control paste, folowed by Calcicur (1-way ANOVA). Release of hydroxyl and clacium ions in the control and Calcicur pastes was faster up to 45 days. pH values for the UltraCal, Calcicur and control pastes were always above 12. The release of hydroxyl and calcium ions occurred more slowly and gradually in the UltraCal paste. Discussion: based on this study's results and methology, the following conclusions were reached: 1. the pH values for the UltraCal, Calcicur and the control pastes were above 12 at all time points. 2. the release of hydroxyl and calcium ions occurred more slowly and gradually in the UltraCal paste. 3. the release of hydroxyl and calcium ions in the control and Calcicur pastes was faster up to 45 days.