Histopathological Evaluation of EDTA Gel on Connective Tissue of Rats

Objective:This study aimed to assess the inflammatory response induced by 24% EDTA Gel (Biodinâmica, Brazil) and 17% EDTA fluid on connective tissue of rats. Methods: 24 male rats were used, Rattus Novergius, Wistar lineage, wich were inoculated with 3x2 mm polietilen tubes with poliuretane sponge, filled with the testing substances, 30 minutes prior to the surgery. The tubes were placed in the upper buccal intraoral tissue of the rats; EDTA gel tubes were inoculated on the right side and EDTA fluid tubes were inoculated on the left side. Animals were sacrificed after 3, 7 and 14 days and 12 weeks, randomly divided into 8 experimental groups G3, G7, G14 and G12s for EDTA Gel, and L3, L7, L14 and L12s for EDTA fluid. Double-blind analysis was carried out through optical microscopy. Groups were analyzed on inflammation severity, presence of inflammatory infiltrate inside the tubes and/or fibrous capsule involving them, predominant cell types. Results: After processing the samples, G3 and G7 presented with severe inflammation; G14, L3, L7 moderate inflammation; inflammatory infiltrate was present inside the tube in G7 only; and fibrous capsule involving the tube started forming in G7 and L3; predominant cells in G3, G7, G14, L3 and L7 were PMNs; meanwhile in G12s, L14 and L12s, macrophages and fibroblasts were predominant. Conclusions: It is possible to conclude that EDTA gel produced more severe inflammatory response than EDTA fluid, mainly in the period of 3 and 7 days, and reverted the condition slower than fluid EDTA.