Effect of Root Dentin Conditioning on the Pushout Bond Strength of Biodentine

Sodium hypochlorite (NaOCl) is the main irrigant to clean root canals. Decalcifying agents are advocated as additional means to condition the root dentin. The aim of this study was to evaluate the effect of alternating (EDTA) or continuous 1-hydroxyethane 1,1-diphosphonic (HEDP) chelation in conjunction with NaOCl irrigation on the pushout bond strength of Biodentine (Septodont, Saint Maur des Fosses, France).

Single root canals of 50 extracted, mature human teeth were divided into 5 groups (n = 10) and enlarged using rotary instruments. Canals were irrigated with 5 mL irrigant after each instrument and then with 5 mL after mechanical preparation as follows: 2.5% NaOCl during and then 2.5% NaOCl, 17% EDTA, or 17% EDTA followed by 2.5% NaOCl after preparation. Continuous chelation with 2.5% NaOCl/9% Dual Rinse HEDP (Medcem GmbH, Weinfelden, Switzerland) during and after preparation. The control group was irrigated with water during and after preparation. Canals were then filled with Biodentine. A horizontal section of 1.5-mm thickness was taken from the middle root third, and a pushout bond test was performed. Data were statistically analyzed using 1-way analysis of variance/Tukey honest significant different test.

The pushout bond strength of Biodentine was significantly higher when the root canal was irrigated with 2.5% NaOCl/9% Dual Rinse HEDP (19.6 ± 2.3 MPa) than with NaOCl alone (15.5 ± 1.5 MPa) or the NaOCl/EDTA sequences (15.7 ± 2.2 MPa and 16.9 ± 2.9 MPa) (P < .05), which did not differ among each other (P > .05). The lowest pushout bond strength values were found with water irrigation (11.5 ± 0.5 MPa) (P < .05 to all other groups).

Irrigation with 2.5% NaOCl/9% Dual Rinse HEDP significantly improved the pushout bond strength of Biodentine to the root canal dentin.