Physico-chemical, biological and mechanical characteristics of new repair materials based on mineral trioxide aggregate and calcium silicate

Abstract

Mineral Trioxide Aggregate (MTA) and Portland cement (PC) have similar composition and bioactive property. Calcium-silicate based cements have been studied. This project is divided into two subprojects. Subproject 1 - aims to develop and to evaluate new materials based on tricalcium and dicalcium silicate associated with radiopacifiers agents, and with indications similar to the MTA. The di and tricalcium silicate and tricalcium silicate cements in association with the radiopacifiers agents: zirconium oxide, niobium oxide or bismuth oxide will be evaluated. For the subproject 1 the initial tests to be performed are setting time, flow, radiopacity and compressive strength, and evaluation of cytotoxicity. Subproject 2 - aims to evaluate physicochemical properties, biocompatibility, chemical characterization, antimicrobial ability and bioactive property of white PC associated with radiopacifiers zirconium oxide and niobium oxide. The measurement of pH and calcium ions will be performed by digital pH meter and atomic absorption spectrophotometry. Assessments of water uptake (uptake / water absorption), solubility and porosity will be conducted according to the methodology proposed by ISO 6876. The MTT and alkaline phosphatase tests will be performed to assess cell viability and mineralization potential after contact with the materials. For chemical characterization and bioactivity evaluation of samples will be made with standardized specimens analyzed by energy dispersive x-ray scanning electron microscope (SEM-EDS), x-ray diffraction (XRD) and infrared spectroscopy (FTIR -ATR). The solubility test will be evaluated in micro-CT. The antimicrobial activity test method is by direct contact of bacteria in planktonic form. Only for the first subproject will be conducted basic tests as setting time, flow, radiopacity and compressive strength. The data obtained for each evaluation will be submitted to ANOVA and Tukey's test, with significance level of 5%. (AU)