Calcium Phosphate Dental Cements

Abstract

AbstractCement systems composed of tetracalcium phosphate powder or powder mixtures of tetracalcium phosphate and brushite were investigated. The liquid components for making the cements include aqueous solutions of H3PO4, Ca(OH)2, or Na2SiO3. For the tetracalcium phosphate cement, strong acidic or basic solutions must be used in order to achieve a short setting time.Our results show that the tetracalcium phosphate and brushite cement can set in a short time under suitable conditions. Humidity, particle size, and pH of liquid have a strong influence on cement setting. Solutions of Ca(OH)2 or Na2SiO3 can be used for making high pH cements and a solution of H3PO4 for a low pH setting cement. To reduce the setting time of cement, the key is to control the hydrolysis of tetracalcium phosphate. The results of hydrolysis indicate that, at 37°C, the single-phase tetracalcium phosphate can only be converted to hydroxyapatite when hydrolyzed in solutions with an H3PO4 solution concentration of ∼5% or with a high pH solution.Both the single-phase tetracalcium phosphate cement and the mixture phase cement have good biocompatibility. Appropriate concentrations of the solutions of Na2SiO 3,Ca(OH)2, or H3P04 can be used in the cements from the perspective of both biocompatibility and cement properties.