title: Influence of Thermal Treatment Conditions on the Properties of Dental Silicate Cements.
abstract: In this study the sol-gel process was used to synthesize a precursor mixture for the preparation of silicate cement, also called mineral trioxide aggregate (MTA) cement. This mixture was thermally treated under two different conditions (1400 °C/2 h and 1450 °C/3 h) followed by rapid cooling in air. The resulted material (clinker) was ground for one hour in a laboratory planetary mill (v = 150 rot/min), in order to obtain the MTA cements. The setting time and mechanical properties, in vitro induction of apatite formation by soaking in simulated body fluid (SBF) and cytocompatibility of the MTA cements were assessed in this study. The hardening processes, nature of the reaction products and the microstructural characteristics were also investigated. The anhydrous and hydrated cements were characterized by different techniques e.g., X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FT-IR) and thermal analysis (DTA-DTG-TG). The setting time of the MTA cement obtained by thermal treatment at 1400 °C/2 h (MTA1) was 55 min and 15 min for the MTA cement obtained at 1450 °C/3 h (MTA2). The compressive strength values were 18.5 MPa (MTA1) and 22.9 MPa (MTA2). Both MTA cements showed good bioactivity (assessed by an in vitro test), good cytocompatibility and stimulatory effect on the proliferation of cells.
authors.affiliation: Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Material Science, Politehnica University of Bucharest, 1-7 Gh. Polizu Street, Bucharest RO-011061, Romania. georgeta.voicu@upb.ro.
authors.forename: Georgeta
authors.initials: G
authors.lastname: Voicu
authors.affiliation: Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Material Science, Politehnica University of Bucharest, 1-7 Gh. Polizu Street, Bucharest RO-011061, Romania. alexbpa_md@yahoo.com.
authors.forename: Alexandru Mihai
authors.initials: AM
authors.lastname: Popa
authors.affiliation: Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Material Science, Politehnica University of Bucharest, 1-7 Gh. Polizu Street, Bucharest RO-011061, Romania. alina.badanoiu@upb.ro.
authors.forename: Alina Ioana
authors.initials: AI
authors.lastname: Badanoiu
authors.affiliation: Department of Fetal and Adult Stem Cell Therapy, Nicolae Simionescu Institute of Cellular Biology and Pathology of Romanian Academy, 8 B.P. Hasdeu Street, Bucharest RO-050568, Romania. loriniordache84@yahoo.com.
authors.forename: Florin
authors.initials: F
authors.lastname: Iordache
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D003738:Dental Cements / Q000737:chemistry*; D004338:Drug Combinations; D008422:Materials Testing; D010087:Oxides / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D003738:Dental Cements; D004338:Drug Combinations; D010087:Oxides; D017640:Silicates; C086631:mineral trioxide aggregate
keywords: biocompatibility; composition; hydration and hardening processes; mineral trioxide cement; properties; setting time; thermal treatment