Evaluation of bioactivity, flowability, pH and calcium release of high-plasticity repair cements

• Grant number: 17/18413-0
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): November 01, 2017
• Effective date (End): October 31, 2018
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Marina Angélica Marciano da Silva
• Grantee: Thiago Bessa Marconato Antunes
• Home Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

The aim of study is to evaluate the properties of bioactivity, flowability, pH and calcium ions release of high-plasticity calcium silicate-based cements (MTA HP, Biodentine and MTA Flow) and to purpose a novel high-plasticity cement composed of tricalcium and dicalcium silicate, bismuth oxide, zinc oxide and in the liquid, distilled water and water-soluble polymer. For the preparation of experimental cement will be used the proportion, by weight, of 80% of tricalcium and dicalcium silicate, 20% of bismuth oxide and 5% of zinc oxide. The liquid will be composed, in volume, by 70% distilled water and 30% water soluble polymer. All the cements will be manipulated in the proportion of 1g powder to 0.3 mL of liquid. For the bioactivity analysis, sample of each material will be immersed in flasks containing 20 mL of HBSS and stocked on stove at 37ºC for 28 days. The samples will be analysed using X-ray dispersive spectroscopy (EDX) integrated at scanning electron microscope. The data of EDX analysis will be used to calculate the proportion calcium/ phosphorus (Ca/P) on the surface of the cements. The flowability test will be realized in according with the ISO specification 6876/2012 and with volumetric methodology in micro-CT. For the evaluation of pH and release of calcium ions, will be used 40 acrylic teeth (n=10) with a root-end cavity of 3-mm depth. The cavities will be filled with the materials, the samples immersed in individual flasks containing 10 mL of deionized water and stocked on stove at 37º C. The pH and ion release will be evaluated after 3, 24 hours and 28 days. The results will be submitted to normality test of D'Agostino and Pearson to select the most adequate statistical test (p < 0.05). (AU)