Influence of irrigants on the coronal microleakage of laterally condensed gutta-percha root fillings

Abstract
To assess in vitro coronal microleakage in extracted human teeth after root-canal treatment, using different endodontic irrigants.Fifty teeth with single root canals were prepared and filled using the lateral condensation of gutta-percha and Endométhasone sealer. Canal preparation consisted of initial shaping of the coronal two-thirds with Gates-Glidden burs size 2 and 3, followed by preparation of the apical stop and step-back flaring with manual files. Each group (n = 10) was irrigated with the following solutions: I--1% NaOCl, II--1% NaOCl + 17% EDTA, III--2% chlorhexidine gel, IV--2% chlorhexidine gel + 1% NaOCl, and V--distilled water. After root-canal filling, the teeth were incubated at 37 degrees C for 10 days followed by 10 days immersion in human saliva and an additional 10 days in India ink. The teeth were cleared and maximum dye penetration was determined digitally in millimetres. Statistical analysis was carried out using the Kruskal-Wallis test.Least leakage occurred with 1% NaOCl + 17% EDTA (2.62 mm) and 2% chlorhexidine gel (2.78 mm) (P > 0.05). NaOCl (3.51 mm), distilled water (6.10 mm) and 2% chlorhexidine gel + 1% NaOCl (9.36 mm) gave increased leakage with a significant difference compared to NaOCl + 17% EDTA and 2% chlorhexidine gel, and compared to one another (P < 0.05).Under the condition of this study, irrigation method during root-canal treatment influenced coronal microleakage. NaOCl + EDTA and chlorhexidine gel allowed better sealing following root filling.