Influence of exposure to phosphoric and polyacrylic acids on selected microscopic and physical/chemical properties of calcium hydroxide cements

Authors : Isabela Dantas TORRES DE ARAÚJO, Renato BARBOSA SOARES, Camila PESSOA LOPES, Isana ÁLVARES FERREİRA, Boniek Castillo DUTRA BORGES

Pages : 69-76

Doi:10.26650/eor.20200057

View : 21 | Download : 16

Publication Date : 2020-05-30

Article Type : Research Paper

Abstract :Purpose: This study aimed to evaluate if the contact of calcium hydroxide cements with polyacrylic and phosphoric acids would alter selected microscopic and physical and chemical properties. Materials and Methods: Chemically activated insert ignore into journalissuearticles values(Hydro C and Dycal Advanced Formula II); and resin-modified photoactivated insert ignore into journalissuearticles values(Ultra-blend Plus); calcium hydroxide cements were examined after exposure to the following different strategies: contact with no substance insert ignore into journalissuearticles values(control group);; rinsing with water and drying; contact with polyacrylic acid, rinsing with water, and drying; and contact with phosphoric acid, rinsing with water, and drying. Surface morphology, determined by scanning electron microscopy insert ignore into journalissuearticles values(SEM);, water sorption and solubility, and the release of hydroxyl ions were evaluated. Results: SEM showed a greater impact of the conditioning acids on the surface of the chemically activated cements. Ultra-blend Plus obtained the highest value of sorption insert ignore into journalissuearticles values(516.8 μg/mm3); and solubility insert ignore into journalissuearticles values(381.1 μg/mm3); and Hydro C had the lowest values 251.9 μg/mm3 and 206.3 μg/mm3 respectively. Considering the release of hydroxyl ions in comparison with time, Hydro C and Ultra-blend Plus presented significant statistical difference for polyacrylic and phosphoric acid subgroups. Conclusion: Hydro C and Dycal presented intensification of surface irregularities after contact with conditioning acids. The chemically activated materials suffered a decrease in sorption and solubility. The action of the conditioning acids promotes greater increase of the release of hydroxyl ions for Hydro C and Dycal.
Keywords : Calcium hydroxide, Hydrogen ion concentration, Solubility, Surface morphology, Water absorption