Cyclic fatigue resistance of yttria-stabilized tetragonal zirconia polycrystals with hot isostatic press processing

Abstract

This study investigated the influence of surface roughness and cyclic loading on fatigue resistance in Y-TZP subjected to hot isostatic pressing (HIP). Fifty Y-TZP cylinders 3.0 mm in diameter were divided into Group A (polished by centerless method; TZP-CP) or Group B (blasted and acid-etched: TZP-SB150E). Twenty five cp-titanium cylinders (Ti-SB150E) were used as a control. Static and cyclic tests were carried out according to ISO 14801. The cyclic fatigue test was performed in distilled water at 37°C. Surface morphology and roughness as well as crystal phase on the surfaces were also evaluated. Fracture force under the static test was 1,765N (TZP-CP), 1,220N (TZP-SB150E), and 850 N (yield force, Ti-SB150E). Fracture values under the cyclic test decreased to approximately 70% of those under the static tests. These results indicate that HIPed Y-TZP with a 3.0-mm diameter has sufficient durability for application to dental implants.

Influence of grade and surface topography of commercially pure titanium on fatigue properties

“…Guilherme et al also reported that no correlation exists between surface roughness and fracture strength 33) ; however, surface treatments for ceramics often cause cracks on ceramics, which propagate internally causing mechanical strength to decrease. For yttria-stabilized tetragonal zirconia polycrystals, shot-blasted and acid-etched samples had lower fracture strengths relative to mirror polished samples 19,34) . However, crack propagation does not occur in metals because of plastic deformation caused by slip and twinning due to the existence of free electrons.…”

“…In contrast, the staircase method used here can be used to quickly derive an average fatigue force with a smaller number of tests 28) . Dental zirconia implants were found to be suitable for use for long periods of time in the oral cavity after determining fracture strengths using the staircase method for various surface topographies 12,19,31) . Here, the staircase method was used to efficiently and accurately perform cyclic loading tests on a small number of samples to evaluate pure titanium durability 28) .…”

“…A hemispherical cap made of carburized quenching steel with chromium plating was placed over one end of each sample, which was then inserted into an aluminum pipe (70-GPa elastic modulus, 5-mm external diameter, 1-mm thickness) with a slit longitudinally running along its length [ Fig. 1(b)] 19) . The sample in the aluminum pipe was then fixed in a holder at a 30° angle from the vertical axis [ Fig.…”

“…clinical setting 3) . As an alternative, fatigue strength has been investigated using cyclic loading [19][20][21] . In 2003, ISO developed a standardized protocol for implant fatigue testing 22) , and there have been several studies that have followed the procedure [23][24][25][26][27] .…”

Estudio in vitro del efecto del empleo del láser de femtosegundo y el ciclado mecánico en la eficacia adhesiva de la interfase circonio-resina

“…To mimic the in vivo stress, is possible to "age" interfaces in a chewing simulator and measure the bonding effectiveness afterward (Nikaido et al, 2002;Frankenberger et al, 2003). Thereby, to simulate occlusal masticatory forces in vitro, cyclic loading is used (Koyama et al, 2012). Cyclic loading is the repeated or fluctuating application of stresses, strains or intensities to locations on structural components, and attempts to replicate the clinical conditions that zirconia restorations are subjected to due to masticatory forces (Attia and Kern, 2004).…”