Fracture resistance and crystal phase transformation of a one‐ and a two‐piece zirconia implant with and without simultaneous loading and aging—An <i>in vitro</i> study

Objective To evaluate the influence of artificial aging on transformation propagation and fracture resistance zirconia implants. Methods One-piece (with integrated implant abutment, 1P; regular diameter [4.1mm]; n = 16) two-piece separate 2P; wide [5 mm]; implants were embedded according to ISO 14801. A titanium–zirconium (Ti-Zr; 4.1 mm diameter) served as a control (n 16). One subgroup 8) each system was simultaneously dynamically loaded (107 cycles; 98N) hydrothermally aged (85°C, 58 days), while other remained untreated. Finally, specimens statically fracture. Potential crystal phase examined at cross sections using scanning electron microscopy (SEM). multivariate linear regression model applied for statistical analyses. Results The 1P (1,117 [SD 38] N; loaded/aged: 1,009 [60] N), 2P (850 [36] 799 [84] Ti-Zr (1,338 [205] 1,319 [247] N) not affected significantly by loading/aging (p .171). However, when comparing systems, they revealed significant differences independent ≤ .001). Regarding structure, zone observed in SEM images only after aging, showed even before aging. After hydrothermal treatment, an increase this monoclinic layer both systems. Conclusions higher compared Loading/aging had no impact wide-body weaker than body implant.