title: Radiopacifier particle size impacts the physical properties of tricalcium silicate-based cements.
abstract: BACKGROUND
  The aim of this study was to evaluate the impact of radiopaque additive, bismuth oxide, particle size on the physical properties, and radiopacity of tricalcium silicate-based cements.
  
  
  METHODS
  Six types of tricalcium silicate cement (CSC) including CSC without bismuth oxide, CSC + 10% (wt%) regular bismuth oxide (particle size 10 μm), CSC + 20% regular bismuth oxide (simulating white mineral trioxide aggregate [WMTA]) as a control, CSC + 10% nano bismuth oxide (particle size 50-80 nm), CSC + 20% nano-size bismuth oxide, and nano WMTA (a nano modification of WMTA comprising nanoparticles in the range of 40-100 nm) were prepared. Twenty-four samples from each group were divided into 4 groups and subjected to push-out, surface microhardness, radiopacity, and compressive strength tests. Data were analyzed by 1-way analysis of variance with the post hoc Tukey test.
  
  
  RESULTS
  The push-out and compressive strength of CSC without bismuth oxide and CSC with 10% and 20% nano bismuth oxide were significantly higher than CSC with 10% or 20% regular bismuth oxide (P < .05). The surface microhardness of CSC without bismuth oxide and CSC with 10% regular bismuth oxide had the lowest values (P < .05). The lowest radiopacity values were seen in CSC without bismuth oxide and CSC with 10% nano bismuth oxide (P < .05). Nano WMTA samples showed the highest values for all tested properties (P < .05) except for radiopacity.
  
  
  CONCLUSIONS
  The addition of 20% nano bismuth oxide enhanced the physical properties of CSC without any significant changes in radiopacity. Regular particle-size bismuth oxide reduced the physical properties of CSC material for tested parameters.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin; Department of Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. Electronic address: saghiri@gmail.com.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Saghiri
authors.affiliation: Department of Restorative Sciences, Texas A&M University Baylor College of Dentistry, Dallas, Texas.
authors.forename: James L
authors.initials: JL
authors.lastname: Gutmann
authors.affiliation: Department of Dental Materials, Kamal Asgar Research Center, Tehran, Iran.
authors.forename: Jafar
authors.initials: J
authors.lastname: Orangi
authors.affiliation: Department of Dental Materials, Kamal Asgar Research Center, Tehran, Iran.
authors.forename: Armen
authors.initials: A
authors.lastname: Asatourian
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin; Department of Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
authors.forename: Nader
authors.initials: N
authors.lastname: Sheibani
mesh_terms: D001729:Bismuth / Q000737:chemistry / Q000627:therapeutic use; D017610:Calcium Compounds / Q000737:chemistry / Q000627:therapeutic use*; D019245:Compressive Strength / Q000187:drug effects; D003287:Contrast Media / Q000737:chemistry / Q000627:therapeutic use*; D003738:Dental Cements / Q000737:chemistry / Q000627:therapeutic use*; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry / Q000627:therapeutic use*; D010316:Particle Size; D012387:Root Canal Filling Materials / Q000737:chemistry / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000379:methods; D017640:Silicates / Q000737:chemistry / Q000627:therapeutic use*
chemical_list: D017610:Calcium Compounds; D003287:Contrast Media; D003738:Dental Cements; D012387:Root Canal Filling Materials; D017640:Silicates; C506393:tricalcium silicate; C033301:bismuth oxide; D001729:Bismuth
keywords: Bismuth oxide; compressive strength; nano particle size; radiopacifier; surface hardness