Shear bond strengths between alumina-toughened zirconia cores and veneering ceramics and their susceptibility to aging

摘要

ABSTRACT Objective:To evaluate the shear bond strength (SBS) between alumina-toughened zirconia (ATZ) cores and veneering ceramics, investigate the effect of aging in artificial saliva on SBS and compare it with that of yttria-stabilized tetragonal zirconia polycrystals(Y-TZP).Methods:Bars ofATZ andY-TZP were layered with veneering ceramics in accordance to the recommendation of the manufacturer. Half of each group (n = 10) was aged at134℃ (under2 bar pressure) in an autoclave for48 h. Subsequently, all specimens were subjected to shear force in a universal testing machine. The interface and fractured surface of the specimens were evaluated using scanning electron microscopy andX-ray energy dispersive spectroscopy.Results:The initial mean SBS values inMPa±SD were28.9±8.0 forATZ and26.2±7.6 forY-TZP. After aging, the meanSBSvalues forATZ andY-TZP were22.9±4.9 MPa and22.8±6.9 MPa, respectively. Neither the differences between theSBS values of theATZ andY-TZP groups nor the influence of aging on all groups were statistically significant.Conclusions:TheSBS between theATZ core and the veneering ceramics was not affected by aging. TheSBS ofATZ to veneering ceramics was not significantly different compared with that ofY-TZP.