Cytotoxicity, genotoxicity and bioactivity of different types of Portland cement and associations with micro and nanoparticles radiopacifiers

Abstract

The Mineral Trioxide Aggregate (MTA) has Portland cement (PC) in its basic composition. Additives and vehicles may be added to the CP to improve its consistency and clinical applicability. The purpose of this study is to assess the biological properties of different formulations of the white CP as well as its modifications. White CP and different modified CPs will be evaluated initially using the following tests: Test of mitochondrial dehydrogenase enzyme to assess cell viability by MTT test (Sigma Chemicals, St. Louis, MO), cell morphology using cresyl violet dye assays, apoptosis / necrosis by the methodology of acridine orange / ethidium bromide and comet assay for evaluation of possible genotoxic damage cellular DNA. In addition, the presence of heavy metals will be evaluated using atomic absorption spectrophotometry. Two materials will be selected among the materials analyzed for a new phase of assessments. At this stage, the materials will be added to different radiopacifying agents - zirconium oxide, niobium oxide, zinc oxide in micro and nanoparticles and microparticles of bismuth oxide. The MTA will be used as a control. MTT tests and necrosis / apoptosis will be conducted to assess the viability of cells after contact with materials. For analysis of cell morphology, cells will be fixed and stained with cresyl violet, and the evaluation of the cell cycle will be evaluated by flow citometry. For the test for assessing alkaline phosphatase, essential for the mineralization process, the kit Labtest will be used. Calcium deposits will be assessed by Alizarin red dye and bioactivity of the materials plus the different agents radiopacificadores will also be evaluated using the gene expression of molecular markers of osteogenesis. The data will be submitted to ANOVA and Tukey's test, with significance level of 5%.