title: Periapical inflammation and bacterial penetration after coronal inoculation of dog roots filled with RealSeal 1 or Thermafil.
abstract: BACKGROUND
  The purpose of this study was to subject 2 carrier-based root filling products to a 4-month microbial challenge in a dog model with histologic markers to assess periapical inflammation and bacterial penetration of the 2 filling materials. Histologic evidence of bacterial penetration and periapical inflammation were the outcome parameters used to compare the products.
  
  
  METHODS
  Teeth were aseptically prepared and then filled with carrier-based Resilon (RealSeal 1 [RS-1], n = 25) or with carrier-based gutta-percha (Thermafil, n = 25) and were left exposed for 4 months. The first control group received a coronal seal over either RS-1 or Thermafil root fillings (n = 8). A second control group was instrumented and left completely empty (n = 8).
  
  
  RESULTS
  Histologic evidence of periapical inflammation was observed in 29% of the Thermafil group and in 9% of the RS-1 group. This difference was only significant when controlling for a possible tooth position effect on inflammation presence (P < .05). Histologic evidence of bacterial penetration was present in 9% of the RS-1 group and in 70% of the Thermafil group. The difference in penetration rates between RS-1 and Thermafil was statistically significant when controlling for any dog or tooth position effects on bacterial penetration (P < .001). Furthermore, there was a statistically significant correlation between histologic evidence of inflammation and histologic evidence of infection (P = .002).
  
  
  CONCLUSIONS
  RS-1 appeared to resist bacterial penetration more effectively than Thermafil under the conditions of this study.
authors.affiliation: Department of Endodontics, University of North Carolina at Chapel Hill, NC 27599-7450, USA.
authors.forename: Derek
authors.initials: D
authors.lastname: Duggan
authors.forename: Roland R
authors.initials: RR
authors.lastname: Arnold
authors.forename: Fabricio B
authors.initials: FB
authors.lastname: Teixeira
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Caplan
authors.forename: Peter
authors.initials: P
authors.lastname: Tawil
mesh_terms: D000818:Animals; D003763:Dental Leakage / Q000517:prevention & control*; D003786:Dental Pulp Cavity / Q000382:microbiology; D003804:Dentin / Q000382:microbiology; D004285:Dogs; D006171:Gutta-Percha; D010485:Periapical Periodontitis / Q000382:microbiology*; D011897:Random Allocation; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation; D019228:Tooth Crown / Q000382:microbiology
chemical_list: D012387:Root Canal Filling Materials; C486892:resilon sealer; D006171:Gutta-Percha