Physical, chemical and biological properties of an experimental Portland-based cement with different radiopacifier agents

Author(s)

Marina Angélica Marciano da Silva

• Document type: Doctoral Thesis
• Press: Bauru.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Bauru (FOB/SDB)
• Defense date: 2014-07-07

Examining board members

Marco Antonio Hungaro Duarte; Clovis Monteiro Bramante; Giulio Gavini; Joao Eduardo Gomes Filho; Rodrigo Ricci Vivan

• Advisor: Marco Antonio Hungaro Duarte

Abstract

The aim of the study was to evaluate the physical, chemical and biological properties of an experimental calcium silicate-based cement with different concentrations of the radiopacifiers zirconium oxide and calcium tungstate. The materials were divided in 6 groups: 1. White MTA (control), 2. White Portland cement (PC), 3. PC with 20% zirconium oxide (ZO), 4. PC/50% ZO, 5. PC with 20% calcium tungstate (CT) and 6. PC/50% CT. The proportions were determined by weight. The cements were manipulated using 0.3 mL of liquid composed of 80% distilled water and 20% propylene glycol. The control was manipulated according to manufacturers instructions. The characterization of the materials was performed using scanning electron microscopy (SEM) in EDS mode and X-ray diffractometrer (XRD). For radiopacity, flowability, film thickness and solubility test, the specifications no 57 of ADA (2000) was followed. To determine the setting time, ASTM C266/2008 specifications was followed. For pH and calcium ion release assessment, the periods of 3, 24, 72 and 168 hours were evaluated. The analysis of dental discolouration was performed using spectrophotometer, stereomicroscopy and SEM. To evaluate the inflammatory response, the test of subcutaneous implantation in rats was used. The use of zirconium oxide and calcium tungstate in association with Portland cement resulted in development of cements with radiopacity nearly (20% radiopacifiers) or above (50%) the recommended by ANSI/ADA specifications n a 57, more prolonged setting time, lower film thickness and higher flowability in comparison with MTAAngelus, an adequate and comparable solubility with MTA-Angelus, high pH and calcium ion release higher than MTA-Angelus in the initial periods and similar at 7 days, absence of dental discolouration and inflammatory response similar to that presented by MTA-Angelus. (AU)

• FAPESP's process: 11/13573-3 - Physicochemical and biological properties of experimental Portland-based sealer containing different radiopacifying agents
• Grantee: Marina Angélica Marciano da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate