title: Nanomodification of mineral trioxide aggregate for enhanced physiochemical properties.
abstract: OBJECTIVE
  To analyse the physicochemical properties of a Nano white mineral trioxide aggregate (NWMTA) and compare it with white mineral trioxide aggregate (WMTA).
  
  
  METHODS
  White mineral trioxide aggregate and NWMTA were prepared and mixed according to the manufacturer's instructions. Surface area of powder before hydration, setting time, X-ray diffraction and microhardness at pH values of 4.4 and 7.4 were evaluated by Brunauer-Emmett-Teller, ISO Specification no.6876, Vickers microhardness, and energy-dispersive X-ray spectroscopy equipped with X-ray colour (dot) map for both cements. anova and Mann-Whitney were used for statistical analysis at a significance level of 0.5.
  
  
  RESULTS
  The mean ± SD of surface area and setting time were 1.8 ± 0.2 m(2) g(-1) and 43 ± 2 min for WMTA and 7.8 ± 1.2 m(2) g(-1) and 6 ± 1 min for NWMTA, respectively. Mean ± SD of Microhardness were 16 ± 2, 51 ± 1, 69 ± 1 and 81 ± 2 for WMTA at pH values of 4.4 and 7.4 and for NWMTA correspondingly. Numbers of open porosity over the surface were 88 ± 24 and 44 ± 13 for WMTA and NWMTA, respectively. Statistical tests revealed significant differences between the groups (P < 0.001) in surface area, setting time and surface hardness for both cements. Uniform distribution of strontium was only observed in NWMTA. However, other compounds were not significantly different.
  
  
  CONCLUSIONS
  Increasing surface area of powder can reduce setting time and increase microhardness even at lower pH values after hydration.
authors.affiliation: Kamal Asgar Research Center (KARC), Azad University, Dental Branch, Tehran, Iran. saghiri@gmail.com
authors.forename: M A
authors.initials: MA
authors.lastname: Saghiri
authors.forename: K
authors.initials: K
authors.lastname: Asgar
authors.forename: M
authors.initials: M
authors.lastname: Lotfi
authors.forename: F
authors.initials: F
authors.lastname: Garcia-Godoy
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D000704:Analysis of Variance; D017610:Calcium Compounds / Q000737:chemistry*; D003799:Dental Stress Analysis; D004338:Drug Combinations; D006244:Hardness; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D044367:Phase Transition; D016062:Porosity; D012387:Root Canal Filling Materials / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D018709:Statistics, Nonparametric; D013324:Strontium / Q000737:chemistry; D013499:Surface Properties; D014867:Water
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D014867:Water; D013324:Strontium