An in vitro comparison of bond strength of various obturation materials to root canal dentin using a push-out test design

The purpose of this in vitro study was to compare the bond strength of various obturation materials to root canal dentin by using a push-out test design. Twenty-five single-rooted extracted human teeth were used in this study. The crowns were removed, and root canal instrumentation was completed by using Endogel-coated 0.06 EndoSequence rotary files (Brasseler, Savannah, GA) and appropriate irrigation with 5.25% NaOCl and a final rinse with 17% EDTA. After instrumentation, the roots were randomly divided into five single-matched cone obturation groups (n = 5 roots/ group), as follows: group 1, gutta percha with Kerr EWT (Kerr Corp, Romulus, MI); group 2, gutta percha with AH Plus (Dentsply, DeTrey, Germany); group 3, Resilon (Pentron Clinical Technologies, Wallingford, CT) and Epiphany (Pentron); group 4, Activ GP (Brasseler) obturation system; and group 5, EndoREZ obturation system (Ultradent, South Jordan, UT). The obturated roots were cut perpendicular to the long access to create 1-mm thick slices from the apical, middle, and coronal thirds. The bond strength was measured for each test slice with a push-out testing machine. Statistical analysis was completed by using a two-way analysis of variance and the post hoc Tukeys test with significance set at p < 0.05. Group 2 showed a significantly (p < 0.05) greater bond strength compared with all other groups. Also, groups 1 and 4 had significantly (p < 0.05) higher bond strengths compared with groups 3 and 5.