title: Evaluation of the physical and chemical properties of two commercial and three experimental root-end filling materials.
abstract: OBJECTIVE
  The aim of this study was to evaluate the pH, calcium release, setting time, and solubility of two commercially available mineral trioxide aggregate (MTA) cements (white MTA Angelus and MTA Bio), and of three experimental cements (light-cured MTA, Portland cement with 20% bismuth oxide and 5% calcium sulfate, and an epoxy resin-based cement).
  
  
  METHODS
  For evaluation of pH and calcium ion release, polyethylene tubes with 1.0 mm internal diameter and 10.0 mm length were filled with the cements and immediately immersed in flasks containing 10 mL deionized water. After 3, 24, 72, and 168 hours, the tubes were removed and the water from the previous container was measured for its pH and calcium content with a pH meter and an atomic absorption spectrophotometer. For analysis of the setting time, Gilmore needles weighing 100 g and 456.5 g were used, in accordance with the American Society for Testing and Materials specification no. C266-03. Solubility of each cement was also tested.
  
  
  RESULTS
  All the cements were alkaline and released calcium ions, with a declining trend over time. After 3 hours, Portland cement + bismuth oxide and MTA Bio had the highest pH and light-cured MTA the lowest. After 1 week, MTA Bio had the highest pH and light-cured MTA and epoxy resin-based cement the lowest. Regarding calcium ion release, after 3 hours, Portland cement + bismuth oxide showed the highest release. After 1 week, MTA Bio had the highest. Epoxy resin-based cement and light-cured MTA had the lowest calcium release in all evaluation periods. Regarding setting times, white MTA Angelus and MTA Bio had the shortest, Portland cement + bismuth oxide had an intermediate setting time, and the epoxy resin-based cement had the longest. The materials that showed the lowest solubility values were the epoxy resin-based cement, Portland cement + bismuth oxide, and light-cured MTA. The highest solubility values were presented in white MTA Angelus and MTA Bio.
  
  
  CONCLUSIONS
  The white MTA Angelus and MTA Bio had the shortest setting times, higher pH and calcium ion release, and the highest solubility. In contrast, the epoxy resin-based cement and light-cured MTA showed lower values of solubility, pH, and calcium ion release.
authors.affiliation: Department of Operative Dentistry, Dental Materials and Endodontics, Dental School of Bauru, University of São Paulo, Bauru, São Paulo, Brazil. rodrigovivan@yahoo.com.br
authors.forename: Rodrigo Ricci
authors.initials: RR
authors.lastname: Vivan
authors.forename: Ronald Ordinola
authors.initials: RO
authors.lastname: Zapata
authors.forename: Márcia A
authors.initials: MA
authors.lastname: Zeferino
authors.forename: Clovis Monteiro
authors.initials: CM
authors.lastname: Bramante
authors.forename: Norberti
authors.initials: N
authors.lastname: Bernardineli
authors.forename: Roberto Brandão
authors.initials: RB
authors.lastname: Garcia
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Hungaro Duarte
authors.forename: Mário
authors.initials: M
authors.lastname: Tanomaru Filho
authors.forename: Ivaldo
authors.initials: I
authors.lastname: Gomes de Moraes
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry; D002118:Calcium / Q000032:analysis; D017610:Calcium Compounds / Q000737:chemistry; D003738:Dental Cements / Q000737:chemistry; D004338:Drug Combinations; D006244:Hardness; D006863:Hydrogen-Ion Concentration; D010087:Oxides / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry; D017640:Silicates / Q000737:chemistry; D012995:Solubility; D013054:Spectrophotometry, Atomic; D013997:Time Factors
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D003738:Dental Cements; D004338:Drug Combinations; D010087:Oxides; D019279:Resin Cements; D012387:Root Canal Filling Materials; D017640:Silicates; C472247:accelerated Portland cement; C086631:mineral trioxide aggregate; D002118:Calcium