Influence of ultrasound and irrigant solutions on the bond strength of glass fiber posts to root canal dentine

Abstract

Objective: Assessment of the influence of theultrasound and irrigant solutions on the bondstrength (BS) of glass fiber posts. Material andMethods: Sixty-six roots of bovine teeth standardizedat 16 mm were used. The roots were submitted to abiomechanical preparation up to size #80 Kerr file,with irrigation of 5ml of saline solution at everyfile change and then filled. The canals underwentpartial desobturation and were divided into 6 groupsaccording to the irrigant solution and the use ofultrasound prior to the post cementation: S – salinesolution; C – 2% chlorhexidine solution; H –2.5%sodium hypochlorite solution; US – saline solution+ ultrasound; UC – 2% chlorhexidine solution +ultrasound; UH – 2.5% sodium hypochlorite solution+ ultrasound. After the cementation of the posts, thespecimens were cut into 3 slices of 2 mm of thickness,perpendicular to its long axis. The samples weresubmitted to push-out test with crosshead speed of1 mm/min and load of 50kgf. The data obtainedwere submitted to ANOVA and Tukey test (level ofsignificance of 5%). Results: Groups C 7.77(±1.8)a,UC 7.82(±1.6)a, S 7.33(±2.2)a, US 6.16(±2.3)a, H5.43(±1.3)b, UH 5.01(±2.3)b values in Mpa. Onlythe irrigant solutions showed statistically significantdifferences (<0.05). Tukey test revealed smallerbond strength for the specimens treated with SodiumHypochlorite (b). Conclusions: The ultrasoundtreatment did not show significant differencecompared with the other groups; therefore, its usecan be indicated prior to the cementation of glassfiber posts without damage to the bond strength. Thesodium hypochlorite solution showed the smallest BSvalues compared with the other groups.