title: Biocompatibility assessment of pastes containing Copaiba oilresin, propolis, and calcium hydroxide in the subcutaneous tissue of rats.
abstract: OBJECTIVE
  To assess the biocompatibility of two endodontic pastes based on calcium hydroxide and propolis, using two vehicles - non-fractionated Copaiba-oilresin (A) and volatile fraction of Copaiba-oilresin (B), in the connective tissue of rats.
  
  
  METHODS
  Fifteen rats had four polyethylene tubes implanted in their backs; each pair of tubes contained one of the pastes. The tube side was considered the control. After 7, 21, and 42 days, the animals were euthanized.
  
  
  RESULTS
  The inflammatory reaction was moderate at seven days for A and severe for B. At 21 days, it was slight for A and moderate for B; and at 42 days, it was slight for A and B. Tissue reaction ranged from slight (7 / 21 days) to no inflammation (42 days) for the control group. Statistical analysis (Kruskal-Wallis test, P < 0.01) demonstrated no significant difference between the pastes and control group (P > 0.01).
  
  
  CONCLUSIONS
  Both pastes presented satisfactory tissue reaction in the connective tissue of rats.
authors.affiliation: Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Lucas
authors.initials: L
authors.lastname: Garcia
authors.forename: Santos
authors.initials: S
authors.lastname: Cristiane
authors.forename: Mestriner
authors.initials: M
authors.lastname: Wilson
authors.forename: Mestriner
authors.initials: M
authors.lastname: Soraya
authors.forename: Ruberval A
authors.initials: RA
authors.lastname: Lopes
authors.forename: Ramos
authors.initials: R
authors.lastname: Mônica
authors.forename: Osvaldo
authors.initials: O
authors.lastname: de Freitas