Bond Strength of Resin Cements on Different Root Dentin Localizations

Objectives: The aim of this study was to compare microtensile bond strength of a self-etching resin cement (Bifix SE, Voco, Germany) with an established resin cement system (Bifix, Futurabond DC, Voco, Germnay) on different root canal dentin localizations (coronal, cervical and apical) in vitro. Methods: In this study 90 single rooted extracted teeth, stored in saline for a maximum of thirty days after extraction were used. All teeth were specially prepared allowing the evaluation of microtensile bond strength on root canal dentin. The specimens were randomly assigned to six experimental groups of fifteen samples each: Group 1: Bifix/ coronal dentin; group 2: Bifix/ cervical dentin; group 3: Bifix/ apical dentin; group 4: Bifix SE/ coronal dentin; group 5: Bifix SE/ cervical dentin; group 6: Bifix SE/ apical dentin. Microtensile bond strength was measured 15 minutes after application using an universal testing machine (Z005, Zwick). All materials were applied as recommended by the manufacturer and light-cured for 60 seconds. Results: For the six test series following microtensile bond strengths were evaluated (mean value and standard deviation in MPa):

Regarding both resin cements, Bifix SE showed singnificantly higher bond strengths on coronal and cervical dentin (p< 0.05, Tukeyxs Test). Focusing on the different localizations, significant lower bond strengths values could only be detected on apical root canal dentin after the use of Bifix SE. In all other groups no significant influence of the localization could be shown. Conclusions: Within the limitations of an in vitro investigation it can be concluded that the new self-etching resin cement showed promising results compared to an established resin cement system.