One-visit versus two-visit root canal treatment: effectiveness in the removal of endotoxins and cultivable bacteria.

INTRODUCTION This clinical study was conducted to compare the effectiveness of 1-visit versus 2-visit root canal treatment in removing endotoxins and cultivable bacteria from primarily infected root canals. METHODS Forty-eight primarily infected root canals were selected and randomly divided into 4 groups: G1, 1% NaOCl; G2, 2% chlorhexidine (CHX) gel; G3, 1% NaOCl + Ca(OH)2; and G4, 2% CHX gel + Ca(OH)2 (all, n = 12). G1 and G2 involved 1-visit treatment, whereas G3 and G4 involved 2-visit treatment with the placement of Ca(OH)2 medication for 14 days. Samples were collected before and after root canal procedures. A chromogenic LAL assay test was used to quantify endotoxins. Culture techniques were used to determine bacterial counts. RESULTS Endotoxins and cultivable bacteria were detected in 100% of the initial samples. All treatment protocols were effective in reducing bacterial load from infected root canals: G1 (1% NaOCl, 99.97%), G2 (2% CHX gel, 99.75%), G3 (1% NaOCl + Ca(OH)2, 99.90%), and G4 (2% CHX gel + Ca(OH)2, 96.81%), respectively (P < .05). No differences were found in bacterial load reduction when comparing 1-visit and 2-visit treatment groups, irrespective of the irrigant tested (P > .05). Higher median percentage values of endotoxin reduction were achieved in the 2-visit treatment groups (G3, 98.01% and G4, 96.81%) compared with 1-visit treatment groups (G1, 86.33% and G2, 84.77%) (all P < .05). CONCLUSIONS Both 1-visit and 2-visit root canal treatment protocols were effective in reducing bacteria and endotoxins, but they were not able to eliminate them in all root canals analyzed. Furthermore, 2-visit root canal treatment protocols were more effective in reducing endotoxins than 1-visit root canal treatment protocols.