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

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 (TM) Z350 XT Flowable using a standard PVC tube (2X2mm). 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 (R) showed the highest SBS (Mean +/- SD) followed by ProRoot (R) MTA and TheraCal LC (R) (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 (R) and Photac (TM) Fil QuickAplicap (TM) were statistically significant different from all other pulp-capping materials groups. ProRoot (R) MTA was statistically significant different than Biodentine (R) (P=0.0001) and Photac (TM) 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 (TM) Z350 XT demonstrated clinically acceptable and high SBS. Urbical LC showed the highest SBS while Biodentine (R) showed the lowest SBS.