Biocompatibility assessment of pastes containing Copaiba oilresin, propolis, and calcium hydroxide in the subcutaneous tissue of rats.

Aim: 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.

Materials And 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).

Conclusion: Both pastes presented satisfactory tissue reaction in the connective tissue of rats.