Biocompatibility of Root Canal Sealers in the Subcutaneous Connective Tissue

Objectives: The purpose of this study was to evaluate the biocompatibility of four root canal sealers: Epiphany, AH Plus, Pulp Canal Sealer and Sealapex. Methods: Sixty rats were divided into four groups. After anesthesia, the dorsum skin was shaved, disinfected and incisions were made to carefully create, by blunt dissection, two subcutaneous pockets. Sterile polyethylene tubes containing freshly mixed tested materials were inserted into the connective tissues in opposite sides, one containing the material and another as control (empty tube). After 7, 15 and 30 days, the implants were removed with the surrounding tissue and immersed in 10% formalin solution for 48 hours. After fixing, the tissue was processed for paraffin embedding, cut in serial 4 um- sections, stained with hematoxylin and eosin and assessed by light microscopy. The descriptive analysis was conducted by a masked pathologist, considering the following criteria: a) the thickness of the fibrous capsule: thin, intermediate or thick; b) connective tissue composition; c) the severity of the inflammatory reaction: mild, moderate, severe; d) presence of giant cells. Results: The results revealed that after a period of 7 days all the sealers induced moderate-to-severe inflammatory reaction and Sealapex presented mild inflammatory reaction. At the 15-day, Epiphany and AH Plus sealers conducted to a moderate inflammatory reaction, Pulp Canal Sealer led to a severe inflammatory reaction and Sealapex had the same mild intensity. After 30 days, mild inflammatory reactions were observed for the Epiphany, AH Plus and Sealapex, while a moderate inflammatory reaction was found for Pulp Canal Sealer. Conclusions: The results of this study revealed that Sealapex presented the lowest level of inflammatory reaction in all the observed periods, although all the sealers presented acceptable biological compatibility. Additional studies are necessary to determine the clinical behavior of these sealers in patients undergoing endodontic therapy.