Thirty-two specimens for each surface treatment, gold or Co-Cr combinations, were randomly divided into two subgroups: one subjected to mechanical and thermal cycling, and the other one was stored in distilled water for 24 h at 37°C (control group) prior to the flexural strength test.
Three liver specimens were positive for surface gene, nine for core gene, three for both and none for the X gene.
Thermochemical properties of these specimens are given for surface temperatures between 1000 and 2000 K in pure oxygen and pure nitrogen plasmas.
For specimens without surface treatments, small particles and higher amounts of cork particles present higher strain value whereas a small amount of bigger particles present worse results than the neat resin.
The experimental results show that, for specimens with surface roughnesses Ra in the range from 0.005μm to 0.1 μm, micro-displacement measurements in the linear range of ± 300μm can be obtained.
Nevertheless, the influence of test frequency for specimens containing surface micro-defects is dominant in the low cycle fatigue (LCF) regime while in the high cycle fatigue (HCF) and very high cycle fatigue (VHCF) range the fatigue life determining parameter is the severity of the micro-notches present along the laser cut surface.
For surface examination, specimens were mechanically polished.
The surface roughness of the specimens was assessed using equipment for surface and texture measurement (TALYSURF Series 2, Taylor Hobson Precision, Leicester, UK).
Histology micrographs of the AlloDerm® and EVPOME specimens were also prepared and examined for surface irregularities.
For the specimens without surface defects failed in VHCF regime, crack initiated from the interior of specimens with inclusions or matrix inhomogeneities as crack origin and the initiation regions were of different extents of rough surface.
