Surface tension and wetting ability comparison of sodium hypochlorite and ethylenediaminetetraacetic acid with and without surfactants

Aim: To evaluate the surface tension and wetting ability (contact angle) of endodontic irrigants as 5.25% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA) with and without addition of surfactants.

Methodology: Eighty halves of single-root teeth were randomly distributed into five groups (n=16) to investigate surface tension and wetting ability of: 5.25% NaOCl; 5.25% NaOCl containing surface-active agents (Hypoclean); 17% EDTA; 17% EDTA with surfactants (EDTA Plus) and freshly obtained distilled water MilliQ as the control group. The surface tension was calculated by the “pendant drop method” and the wettability of the surface by the “sessile drop method”. All measurements were taken at room temperature (20 °C). Data were analyzed by one-way analysis of variance (ANOVA).

Results: The highest surface tension and the least wetting ability were observed for distilled water and 5.25% sodium hypochlorite (p>0.05). EDTA with or without surfactants and Hypoclean showed a significant lower surface tension and a higher wetting ability than distilled water at room temperature (p<0.001). The addition of surfactants reduced the surface tension and the contact angle of sodium hypochlorite (as in Hypoclean, p<0.001), but not those of EDTA (as in EDTA Plus, p>0.05).

Conclusions: Addition of surfactant agents reduces the surface tension and increases the wetting ability of the sodium hypochlorite; surfactants did not affect surface tension and wetting ability of EDTA.