Shear Bond Strength of a Resin Composite to Six Pulp Capping Materials Used in Primary Teeth

Aim: The purpose of this in vitro study was to assess the shear bond strength (SBS) and bond failure types of a resin-composite to six pulp-capping materials used in primary teeth. Study design: Eight-disc specimens from each pulp-capping material (6 groups) to bond to Filtek™ Z350 XT Flowable using a standard PVC tube (2×2mm). All groups were prepared according to the instruction of the manufacturer. The SBS was measured with a crosshead speed of 0.5 mm/min using a universal testing machine. Failure mode evaluation was completed using Digital Microscope by two independent examiners. Results: Urbical LC® showed the highest SBS (Mean±SD) followed by ProRoot® MTA and TheraCal LC® (35.422±2.910, 22.114±2.515, and 21.175±1.983) respectively. ANOVA showed significant differences between all groups (P=0.0001). Urbical LC® and Photac™ Fil QuickAplicap™ were statistically significant different from all other pulp-capping materials groups. ProRoot® MTA was statistically significant different than Biodentine® (P=0.0001) and Photac™ Fil (P=0.0001). The total number of bond failure was recorded for cohesive B failure/cohesive in the pulp-capping material (14) and adhesive failure (14). Conclusion: Most of the tested pulp-capping materials bonded to Filtek™ Z350 XT demonstrated clinically acceptable and high SBS. Urbical LC showed the highest SBS while Biodentine® showed the lowest SBS.