title: Particle size of a new endodontic cement compared to Root MTA and calcium hydroxide.
abstract: BACKGROUND
  Particle size and distribution can influence the properties of materials. This study analyzed and compared the particle size of Root MTA, calcium hydroxide (CH), and a new endodontic cement called calcium enriched material (CEM).
  
  
  METHODS
  The particle size of each material was analyzed three times using 0.05 mg of test material with a particle size analyzer. The particle size distribution ranges, the cumulative percentage and the mean of particle sizes were calculated. One-way ANOVA, Tukey, and Chi-square tests were used for statistical analyses.
  
  
  RESULTS
  Results demonstrated that the distribution of particles was dissimilar. Particle mean size in the three different materials was not significantly different. However, the cumulative percentage of CH and CEM cement particles size demonstrated significant difference (P<0.05). Among the various particle size distributions, the particle distribution in the size range of ≤30 μm showed significant difference between materials (P<0.05). Interestingly, the smallest range of particle size belonged to CEM cement.
  
  
  CONCLUSIONS
  The high percentage of small particles found in CEM cement provides desirable properties such as effective seal, good setting time and film thickness in addition to favorable flow and adaptability.
authors.affiliation: Researcher, Dental Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Soheilipour
authors.forename: Sanam
authors.initials: S
authors.lastname: Kheirieh
authors.forename: Majid
authors.initials: M
authors.lastname: Madani
authors.forename: Alireza
authors.initials: A
authors.lastname: Akbarzadeh Baghban
authors.forename: Saeed
authors.initials: S
authors.lastname: Asgary
keywords: CEM cements; Calcium hydroxide; New endodontic material; Particle size; Root MTA