A comparative evaluation of inflammatory response of various root canal irrigants in charles foster rat models

Abstract

Aim: The aim is to evaluate the inflammatory response of root canal irrigants such as sodium hypochlorite, mixture of sodium hypochlorite (NaOCl) with ethylenediaminetetraacetic acid (EDTA) versus a new root canal irrigant mixture of tetracycline isomer, an acid, and a detergent (MTAD). Materials and Methods: Eighteen Charles foster rats were injected with 0.1 ml of the irrigant solution; normal saline served as control. Biopsies of the skin were obtained at 2 h, 2 days, and 2 weeks. The chronic and acute inflammatory responses were studied in specimen. Results: Three percent NaOCl-induced maximum acute inflammatory response, followed by mixture of 3% NaOCl with 17% EDTA. MTAD did not evoke any significant acute inflammatory response. All the irrigants evoked almost equal chronic inflammatory reaction. During 2 h study 3% NaOCl, being the most inflammatory, mixture of 3% NaOCl with 17% EDTA being the least inflammatory. Chronic inflammatory reactions further aggravated in each treatment group at 2 days except in MTAD-treated rats skin which sloughed before 2 weeks with no sign of resolution of chronic inflammation. Conclusion: This study suggests that NaOCl evokes rapid acute inflammatory response compared to other irrigants under study, but subsided in 2 days. Its combination with EDTA also had similar inflammatory response as NaOCl alone, but of lower magnitude, suggesting NaOCl with EDTA as better root canal irrigant. MTAD caused necrosis of the skin tissue at 2 days and sloughing; thereafter, this study does not suggest its use as a root canal irrigant.