I R Oliveira1, V C Pandolfelli, M Jacobovitz. 1. Institute for Research and Development, University of Vale do Paraiba, São José dos Campos, SP Materials Engineering Department, Federal University of São Carlos, São Carlos, SP Department of Endodontics, Paulista Association of Dental Surgeons, São Carlos, SP, Brazil.
Abstract
AIM: To evaluate the influence of additives on several physical and chemical properties of a novel endodontic cement based on calcium aluminate in comparison with mineral trioxide aggregate (MTA). METHODOLOGY: Manipulation tests, measurements of temperature, pH, ionic conductivity, compressive strength, apparent porosity, and pore size distribution were carried out on Gray-MTA (Angelus) and calcium aluminate cement (Secar-71, Kerneos) with and without various additives: a polymeric dispersant, CaCl(2) as plasticizer, and ZnO as radiopacifier. RESULTS: The calcium aluminate cement without additives had a setting time of approximately 60min, and when combined with Li(2) CO(3) it decreased to 10min. The material also released Ca(2+) ions and alkalinized the medium. Moreover, the addition of additives (dispersant, plasticizer, and radiopacifier) improved its properties resulting in a material with a viscosity of 57mPas, enhanced handling properties, a mechanical strength of 81MPa, a porosity of 4% and pores with small diameter (0.25μm). MTA had no temperature increase (that indicates setting) up to 400min, a mechanical strength of 34MPa, and porosity of 28% with pores 2.5μm in diameter. CONCLUSION: The novel cement set more rapidly, had better fluidity, improved handling properties, higher mechanical strength, and reduced porosity with lower pore size compared to Gray-MTA Angelus.
AIM: To evaluate the influence of additives on several physical and chemical properties of a novel endodontic cement based on calcium aluminate in comparison with mineral trioxide aggregate (MTA). METHODOLOGY: Manipulation tests, measurements of temperature, pH, ionic conductivity, compressive strength, apparent porosity, and pore size distribution were carried out on Gray-MTA (Angelus) and calcium aluminate cement (Secar-71, Kerneos) with and without various additives: a polymeric dispersant, CaCl(2) as plasticizer, and ZnO as radiopacifier. RESULTS: The calcium aluminate cement without additives had a setting time of approximately 60min, and when combined with Li(2) CO(3) it decreased to 10min. The material also released Ca(2+) ions and alkalinized the medium. Moreover, the addition of additives (dispersant, plasticizer, and radiopacifier) improved its properties resulting in a material with a viscosity of 57mPas, enhanced handling properties, a mechanical strength of 81MPa, a porosity of 4% and pores with small diameter (0.25μm). MTA had no temperature increase (that indicates setting) up to 400min, a mechanical strength of 34MPa, and porosity of 28% with pores 2.5μm in diameter. CONCLUSION: The novel cement set more rapidly, had better fluidity, improved handling properties, higher mechanical strength, and reduced porosity with lower pore size compared to Gray-MTA Angelus.