Abstract
The bond strength of the root canal sealers to dentin and core material seems to be a very important property for maintaining the integrity and the seal of root canal filling. This in vitro study aimed to evaluate and compare the bond strength of three different root canal sealers. Forty five extracted single-root human teeth were prepared using ProTaper system. Teeth were divided into three groups (n=15) for obturation using AH Plus, RealSeal and a new, experimental endodontic sealer containing hydroxyapatite. Each tooth was obturated using warm vertical condensation technique in the apical third and gutta-percha injection in the middle and coronal thirds of the root canal. All teeth were sectioned transversally at the apical and middle thirds into 1 mm thick discs. Push-out tests were performed using a universal mechanical testing machine (Lloyd Instruments – LR5k plus). The maximum load at failure was recorded and divided by the area to obtain the bond strength in MPa. Using a stereomicroscope (STEMI 2000 C Zeiss, Jena, Germany), at a magnification of 20x, the interface where the obturation failure occurred was identified. Statistical analysis was performed and the result showed non significant differences between the three endodontic sealers at each level obturation. Also, the stereomicroscopic analysis showed a good adhesion to dentin for all sealers. The experimental sealer adhesion is comparable to that of the two consecrated materials. Keywords: push-out test, bond strength, endodontic sealer, root canal obturation