title: Subcutaneous connective tissue reactions to various endodontic biomaterials: an animal study.
abstract: OBJECTIVE
  Biocompatibility of root-end filling materials is a matter of debate. The aim of this study was to compare the biocompatibility of a variety of commercial ProRoot WMTA cements and a resin-based cement (Geristore®) with different pH values of setting reaction and different aluminum contents, implanted into the subcutaneous connective tissue of rats at various time intervals.
  
  
  METHODS
  Fifty Sprague-Dawley rats were used in this study. Polyethylene tubes were filled with Angelus WMTA, ProRoot WMTA, Bioaggregate, and Geristore. Empty control tubes were implanted into subcutaneous tissues and harvested at 7-, 14-, 28- and 60-day intervals. Tissue sections of 5 μm were stained with hematoxylin and eosin and observed under a light microscope. Inflammatory reactions were categorized as 0, none (without inflammatory cells); 1, mild (inflammatory cells ≤25); 2, moderate (25-125 inflammatory cells); and 3, severe (>125 inflammatory cells). Statistical analysis was performed with Kruskal-Wallis and Mann Whitney U tests.
  
  
  RESULTS
  ProRoot WMTA and Angelus elicited significantly less inflammation than other materials (P<0.05). After 7 days, however, all the materials induced significantly more inflammation than the controls (P<0.05). Angelus-MTA group exhi-bited no significant differences from the Bioaggregate group (P=0.15); however, ProRoot WMTA elicited significantly less inflammation than Bioaggregate (P=0.02). Geristore induced significantly more inflammation than other groups (P<0.05).
  
  
  CONCLUSIONS
  Geristore induced an inflammatory response higher than ProRoot WMTA; therefore, it is not recommended for clinical use.
authors.affiliation: Head, Center for Excellence in Endodontic Materials, Professor Kamal Asgar Research Center (KARC) For Dental Materials and Devices, Tehran, Iran.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Saghiri
authors.forename: Nader
authors.initials: N
authors.lastname: Tanideh
authors.forename: Franklin
authors.initials: F
authors.lastname: Garcia-Godoy
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Lotfi
authors.forename: Kasra
authors.initials: K
authors.lastname: Karamifar
authors.forename: Dariush
authors.initials: D
authors.lastname: Amanat
keywords: Bioaggregate; Geristore; biocompatibility; endodontic cement; mineral trioxide aggregate