title: Comparative evaluation of the calcium release from mineral trioxide aggregate and its mixture with glass ionomer cement in different proportions and time intervals - An in vitro study.
abstract: BACKGROUND
  Addition of glass ionomer cement (GIC) has been suggested to improve the setting time and handling characteristics of mineral trioxide aggregate (MTA). This study evaluated the effect of adding GIC to MTA in terms of calcium release, an issue that has not been previously studied.
  
  
  METHODS
  The study comprised four groups with five samples each: a control group of MTA alone and experimental groups I (1MTA:1GIC), II (2MTA:1GIC), and III (1MTA:2GIC) based on the mixture of MTA and GIC powders in the respective proportions by volume. Calcium release from the samples was measured by atomic absorption spectrophotometry at 15 min, 6 h, 24 h, and 1 week after setting. The level of statistical significance was set at p < 0.05.
  
  
  RESULTS
  Groups I (1MTA:1GIC) and III (1MTA:2GIC) released significantly less calcium than the control group at all time periods, except at 15 min for group I. Group II (2MTA:1GIC) showed no significant difference in calcium release compared to the control at any time period. Group II exhibited greater calcium release than group I or III at all time periods, with significant differences between groups I and II at 1 week and between groups I and III at 24 h and 1 week. There were no statistical differences in calcium release between groups I and III.
  
  
  CONCLUSIONS
  Adding GIC to improve the setting time and handling properties of the MTA powder can be detrimental to the calcium-releasing ability of the resultant mixture, depending on the proportion of GIC added. Adding MTA and GIC at a proportion of 2:1 by volume did not impact calcium release from the mixture. These findings should be verified through further clinical studies.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences (Manipal University), Light House Hill Road, Mangalore 575001, Karnataka, India.
authors.forename: Surbhi
authors.initials: S
authors.lastname: Sawhney
authors.affiliation: Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences (Manipal University), Light House Hill Road, Mangalore 575001, Karnataka, India.
authors.forename: A R
authors.initials: AR
authors.lastname: Vivekananda Pai
keywords: Atomic absorption spectrophotometry; Calcium ion; Glass ionomer cement; Mineral trioxide aggregate