| Objective: Comparing the different concentration of HEMA in treatment agents to analyze the difference of the immediate bonding strength and strength after aging between Zirconium oxide and resin in order to get the optimal range of HEMA concentration to serve the clinic.Methods: Cut the porcelain pieces without sintered into 16 cuboids(12mm×10mm×10mm)and then sinter those cuboids.The specimens were divided to 2 groups(immediate group and aging group)randomly,and then those in each group were divided into 4 subgroups.Each four surfaces of the cuboid were treated with the sand blast and surface treatment agent with 0%、7%、14% HEMA and ZPP,and then one resin core of 2mm diameter were made in the center of the surface.Specimens in immediate group were put into the distilled water of 37 degrees for 24 hours.Specimens in aging group were put into the thermal cycling machine,cycled for 10000 times.Easy test machine was used to do the shearing test and get the shearing strength.Using Stereo Microscope of 50 times to observe the failure modes and appearance of the fracture surface Results: Before the thermal cycling,group C had the highest shearing bonding strength of 24.01± 5.56 MPa and group B had the lowest strength of the bonding strength of 18.13±6.81 MPa,the strength of group A and D were between group C and B.The P value between group A and C,B and C were 0.017 and 0.012 separately,and both were less than 0.05 and were statistically significant.After the thermal cycling,shearing bonding strength of all groups were decreased by 50%-60%.Group C dropped the most and group A dropped the least.There were no significance within aging groups,while there were significance between immediate and aging group.Conclusions: In this experiment,The higher the concentration of HEMA is,the strongest the immediate bonding strength between Zirconium oxide ceramic and resin cements are. |
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