Purpose: To evaluate the effect of different concentrations of ethylene-diamine-tetra acetic acid (EDTA) on bond strength (BS) and nanoleakage (NL) of fiber posts bonded into root canals.
Materials and methods: Seventy-two single roots were endodontically treated and divided into six groups (n = 12), according to the combination of the following factors: surface treatment (no irrigation [control], 17% EDTA, or 24% EDTA), and composite cement applied with an adhesive used in a self-etch mode (Single Bond Universal/RelyX Ultimate [SB], 3M Oral Care; Ambar Universal/Allcem [AM], FGM). After fiber post cementation, six 1-mm-thick disks were obtained for each root. Push-out bond strength (BS) was evaluated using 8 specimens per group, and the other 4 specimens were used to examine nanoleakage (NL). Data from BS and NL of each adhesive were evaluated by two-way ANOVA (surface treatment vs root region) and Tukey's test (α = 0.05).
Results: The application of 17% and 24% EDTA did not influence the bond strengths of either adhesive. In general, the application of 17% and 24% EDTA increased NL values for both adhesives.
Conclusion: Pre-treatment with different concentrations of EDTA was not able to improve the adhesion of fiber posts into root canals with universal adhesives..
Keywords: adhesive; bond strength; fiber posts; root dentin.