Comparison of the Push-Out Bond Strength of 5th, 6th, 7th and 8th Generation Bonding Agents to Intracanal Dentin of Primary Anterior Teeth

Due to the importance of primary anterior teeth in chewing, pronunciation of words, self-confidence, facial appearance of children, efforts to preserve these teeth continue. The aim of the present study was to evaluate the push-out bond strength of 5th, 6th, 7th, and 8th generation bonding agents to intracanal dentin of primary anterior teeth which are reconstructed with the composite posts.

The present experimental in vitro study was conducted on 60 extracted primary anterior teeth with at least two-thirds of the root length remaining. The teeth were randomly divided into five groups: 5th generation (3M Adper single bond 2 Adhesive-USA), 6th generation (clearfil SE bond, Japan), 7th generation (kerr-optibond all in one Adhesive-Italy), and 8th generation total-etch and 8th generation self-etch (GC-G permio bond-Japan) bonding agents. After root canal preparation, prepared canals were filled with Metapex. The coronal 3mm of the canals was etched and impregnated with the dentin bonding agents. Then, they were restored with composite. The push-out test was performed to evaluate the bond strength of adhesives. Accordingly, by a light microscope the failure modes were determined.

The mean bond strength of 5th, 6th, 7th, and 8th generation (self-etch, total-etch) bonding agents was 4.36±2.15, 3.88±1.55, 4.29±2.02, 12.84±3.62, and 7.77±3.81 MPa, respectively. The push-out bond strength of the 8th generation bonding agent using both self-etch (p=0.000) and total-etch techniques was higher than the 5th, 6th, and 7th generation bonding agents (p=0.032, 0.01, 0.027, respectively). No significant difference was found between the bond strength of the 5th, 6th, and 7th generation bonding agents.

The push-out bond strength of the 8th generation bonding system was higher than the other groups. Therefore, the 8th generation bonding agents can be used to bond composite posts to intracanal dentin of primary anterior teeth. Also, self-etch (8th generation) has higher bond strength compared to the total-etch technique.