To assess the effects of 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA), and 2% chlorhexidine (CHX), individually and in combination, as part of an irrigation protocol on furcal perforations treated with ProRoot MTA, using the dye extraction (DE) method for evaluation. Sixty intact mandibular molars were used. Perforations were created with a 1.2 mm diameter at the FA of the molars and sealed the perforations with MTA. Then the samples were divided randomly after to six groups according to the irrigant used: Group 1 (n = 10), 5.25% NaOCl
Group 2 (n = 10), 17% EDTA
Group 3 (n = 10), 2% CHX, Group 4 (n = 10), saline serum (control group)
Group 5 (n = 10), (5.25% NaOCl,17% EDTA, 5.25% NaOCl) protocol replaced with saline serum between each irrigant
and Group 6 (n = 10), (5.25% NaOCl, 17% EDTA, 2% CHX). Specimens were immersed for 24 h in 2% methylene blue. Subsequently, a DE test was performed. Data analysis employed the One-Way ANOVA and LSD tests. The significance level was set at 0.05. DE values between groups revealed significant differences in this study (p <
0.01). Control group DE values were less than NaOCl (p <
0.05), EDTA (p <
0.01), CHX (p <
0.01), protocol (NaOCl - EDTA - NaOCl) (p <
0.01), and protocol (NaOCl - EDTA - CHX) (p <
0.01) groups, proposing the order: Control group <
NaOCl <
EDTA <
CHX≤(NaOCl - EDTA - NaOCl) protocol≤(NaOCl - EDTA - CHX) protocol. Deterioration of the MTA sealing ability was noted when contacted with 5.25% NaOCl, 17% EDTA, 2% CHX, and both protocols.