title: Effect of particle size on calcium release and elevation of pH of endodontic cements.
abstract: OBJECTIVE
  Elevation of pH and calcium ion release are of great importance in antibacterial activity and the promotion of dental soft and hard tissue healing process. In this study, we evaluated the effect of particle size on the elevation of pH and the calcium ion release from calcium silicate-based dental cements.
  
  
  METHODS
  Twelve plastic tubes were divided into three groups, filled with white mineral trioxide aggregate (WMTA), WMTA plus 1% methylcellulose, and nano-modified WMTA (nano-WMTA), and placed inside flasks containing 10 ml of distilled water. The pH values were measured using a pH sensor 3, 24, 72, and 168 h after setting of the cements. The calcium ion release was measured using an atomic absorption spectrophotometer with same sample preparation method. Data were subjected to two-way analysis of variance (anova) followed by post hoc Tukey tests with significance level of P < 0.05.
  
  
  RESULTS
  Nano-WMTA showed significant pH elevation only after 24 h (P < 0.05) compared with WMTA, and after 3, 24, and 72 h compared with WMTA plus 1% methylcellulose (P < 0.05). Nano-WMTA showed significantly higher calcium ion release values compared to the other two groups (P < 0.05).
  
  
  CONCLUSIONS
  Nano-modification of WMTA remarkably increased the calcium ion release at all time intervals postsetting, which can significantly influence the osteogenic properties of human dental pulp cells and as a consequence enhance mineralized matrix nodule formation to achieve desirable clinical outcomes. However, the increase in pH values mainly occurred during the short time postsetting. Addition of 1% methylcellulose imposed a delay in elevation of pH and calcium ion release by WMTA.
authors.affiliation: Departments of Ophthalmology & Visual Sciences and Biomedical Engineering, University of Wisconsin School of Medicine and Public health, Madison, WI, USA.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Saghiri
authors.forename: Armen
authors.initials: A
authors.lastname: Asatourian
authors.forename: Jafar
authors.initials: J
authors.lastname: Orangi
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Lotfi
authors.forename: Jason W
authors.initials: JW
authors.lastname: Soukup
authors.forename: Franklin
authors.initials: F
authors.lastname: Garcia-Godoy
authors.forename: Nader
authors.initials: N
authors.lastname: Sheibani
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D003738:Dental Cements / Q000737:chemistry*; D004338:Drug Combinations; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008747:Methylcellulose / Q000737:chemistry; D053758:Nanoparticles; D010087:Oxides / Q000737:chemistry*; D010316:Particle Size; D017640:Silicates / Q000737:chemistry*; D013054:Spectrophotometry, Atomic
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D003738:Dental Cements; D004338:Drug Combinations; D010087:Oxides; D017640:Silicates; C086631:mineral trioxide aggregate; D008747:Methylcellulose; D002118:Calcium
keywords: calcium ion; calcium silicate; nano-WMTA; pH value