title: Histological analysis of the biocompatibility of three different calcium hydroxide-based root canal sealers.
abstract: OBJECTIVE
  To histologically evaluate the behavior of the subcutaneous tissue of rats after placement of polyethylene tubes filled with calcium hydroxide-based root canal sealers (Sealapex, Apexit e Sealer 26).
  
  
  METHODS
  The study employed 60 rats, which were divided into eight groups, being four experimental groups with 10 rats each, and four control groups with five rats. Analysis was conducted at 48 hours, 7, 21 and 60 days.
  
  
  RESULTS
  Histological analysis revealed that all sealers were irritant; however, the intensity varied between each sealer and as a function of time. At the initial periods (48 hours and seven days), all materials demonstrated similar outcomes, with inflammatory reaction from severe to moderate, respectively. At the final periods (21 and 60 days), the tissue reactions to the implants containing Sealapex displayed an active status yet with regression, compared to the Apexit and Sealer 26. The control groups exhibited less inflammatory cells than the experimental groups, keeping a reaction status with regression.
  
  
  CONCLUSIONS
  The results achieved in this study revealed that the Sealapex sealer was the most compatible, followed by Apexit and Sealer 26.
authors.affiliation: Department of Dentistry, University of Pernambuco, Pernambuco, Brazil.
authors.forename: Heloisa Helena Pinho
authors.initials: HH
authors.lastname: Veloso
authors.forename: Roberto Alves
authors.initials: RA
authors.lastname: do Santos
authors.forename: Túlio Pessoa
authors.initials: TP
authors.lastname: de Araújo
authors.forename: Denise Piotto
authors.initials: DP
authors.lastname: Leonardi
authors.forename: Flares
authors.initials: F
authors.lastname: Baratto Filho