Reliability and Properties of Ground Y-TZP-Zirconia Ceramics

Abstract

Yttria-stabilized zirconia ceramics is a high-performance material with excellent biocompatibility and mechanical properties, which suggest its suitability for posterior fixed partial dentures. The hypothesis under examination is that the strength and reliability of Y-TZP zirconia ceramics are affected by the inner surface grinding of crowns, and vary with the grinding parameter. Flexural strength, surface roughness, and fracture toughness were determined on samples machined by face and peripheral grinding with varied feed velocities and cutting depths. Results have been compared with those on lapped samples. Analysis of variance and Weibull parameter were used for statistical analysis. It was found that inner surface grinding significantly reduces the strength and reliability of Y-TZP zirconia compared with the lapped control sample. Co-analysis of flexural strength, Weibull parameter, and fracture toughness showed counteracting effects of surface compressive stress and grinding-introduced surface flaws. In conclusion, grinding of Y-TZP needs to be optimized to achieve the CAD/CAM manufacture of all-ceramic restorations with improved strength and reliability.

Effect of ultrashort pulsed laser on bond strength of Y-TZP zirconia ceramic to tooth surfaces

“…This result agreed with the results of previous studies which reported higher bond strengths with the use of MDPbased primer 8,42) . This could be due to the capability of acidic functional monomer MDP reacting with the substrate [13][14][15][16][17][18][19] .…”

“…Unlike conventional dental ceramics, high-strength ceramics such as yttria-tetragonal zirconia polycrystal (Y-TZP) have high crystalline content and comprise many crystalline filler particles without a glass phase at the crystalline border 13) . Therefore, these ceramics are not suitable for acid etching 8,[14][15][16] .…”

Digital dentistry: an overview of recent developments for CAD/CAM generated restorations

“…In recent years, CAD/CAM production has clearly expanded the palette of materials for dental prosthe ses by providing access to new ceramic materials with high dependability. 15,[28][29][30][31] The stability values of zirconium oxide ceramics permit, in many areas of indi cation, the use of this material as an alternative to metal frames for perma nent prostheses. 30 The production of long-term temporary prostheses has, as a result of the use of a virtual wax up on the computer, become faster, more convenient and more pre dictable.…”

Grinding damage assessment on four high-strength ceramics

“…For zirconia, the ground surface will show under XRD a localized phase transformation, which involves an increased resistance to crack propagation. Nevertheless, depending on the diamond grit size and shape and the time-dependence of the applied forces, deep reaching surface cracks will show both a reduction in strength and reliability [4][5][6][7][8][9][10]. Grinding dense alumina will also induce surface residual compressive stresses which can enhance the average strength, but increasing the depth of cut will produce machining flaws in form of surface cracks penetrating deeper than the surface compressive layer lowering the reliability and strength [11,12].…”