title: Cytotoxicity of Cold Ceramic Compared with MTA and IRM.
abstract: BACKGROUND
  Biocompatibility is a desirable feature for root-end filling materials. In this study we aimed to compare a new material called cold ceramic (CC) with intermediate restorative material (IRM) and mineral trioxide aggregate (MTA) using Methyl-tetrazolium bromide (MTT) assay.
  
  
  METHODS
  The materials were tested in fresh and set states: (n=108). The cytotoxicity was compared using L929 fibroblasts as an indicator; tested materials were eluted with culture medium according to ISO: 109935 standard. Distilled water and culture medium served as positive and negative controls, respectively (n=36). The results were evaluated at 1, 24 hours and 7 days. Data were statistically analyzed by one-way ANOVA for each time interval and material status and t-tests.
  
  
  RESULTS
  The cytotoxicity of the tested materials were statistically different at the various time intervals (P<0.001). IRM was the most cytotoxic root-end filling material (P<0.001), MTA demonstrated the least cytotoxicity followed by CC.
  
  
  CONCLUSIONS
  Despite displaying the greatest cytotoxicity, IRM is approved by the American Food and Drug Administration (FDA). Cold ceramic had significantly lower cytotoxicity compared to IRM, in all but one subgroup. Further investigations are required to assess the clinical applicability of this novel material.
authors.affiliation: Department of Endodontics, Iranian Center for Endodontic Research, Dental Research Center, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Mozayeni
authors.forename: Amin
authors.initials: A
authors.lastname: Salem Milani
authors.forename: Laleh
authors.initials: L
authors.lastname: Alim Marvasti
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Mashadi Abbas
authors.forename: Seyed Jalil
authors.initials: SJ
authors.lastname: Modaresi
keywords: Cold ceramic; Cytotoxicity; Fibroblast; Intermediate restorative material; MTA; New endodontic material; Root end filling