Thermodynamic study on the phase diagram of the Hg-Ca and Hg-Sr binary systems for dental amalgam restoration application

Abstract

Dental amalgam, known for its biocompatibility and ductility, is widely used in restorative materials. In dental crown restorations, studying the interactions between amalgam fillings and crown tissues, particularly the roles of calcium (Ca) and strontium (Sr), is essential for improving function stability and biocompatibility. This study conducts critical literature evaluation and thermodynamic optimization of binary systems involving mercury (Hg) with Ca and Sr, focusing specifically on their suitability for dental amalgam restoration. Using first-principles calculations (FPC), the enthalpies of formation for compounds within the Hg-Ca and Hg-Sr binary systems were calculated in this work. Thermodynamic modeling of the liquid solution employed the modified quasichemical model in the pair approximation (MQM), uncovering significant short-range ordering. Conversely, solid phases were modeled using the compound energy formalism (CEF). The incorporation of FPC proves to be a valuable and effective method, providing essential insights to complement the calculation of phase diagrams (CALPHAD) modeling approach. Ultimately, this research significantly enhances our understanding of the thermodynamic characteristics of Hg-X alloys, with notable implications for their potential application in dental amalgam restoration.