Effects of ceramic microbeads on bonding between a zirconia framework and layered resin composite

This study was conducted to evaluate the effects of ceramic microbeads on the bond strength between resin and zirconia. Microbeads made of zirconia (TZ) and zircon (ZS) were treated with and without hydrofluoric acid (HF). The microbeads were sintered to zirconia disks using intermediate feldspathic porcelains. Two control groups, NB (without microbeads) and AS (without porcelain and microbeads), were also prepared. All specimens were treated with a phosphate primer and veneered with a light-curing resin composite. The 24-h shear bond strengths were determined and analyzed by the Tukey-Kramer test (α=0.05, n=10). The TZ-HF specimen exhibited the highest bond strength, followed by TZ, ZS-HF, ZS, AS, and NB. Scanning electron microscopy observations revealed that the TZ-HF specimen had a complicated debonded surface, and it included microconcavities where the microbeads were detached. Sintering etched zirconia beads onto a zirconia framework with feldspathic porcelains is useful for bonding layered resin composite materials.