Vision64

A Bruker Contour GTK (Bruker Nano GmbH, Berlin, Germany) optical noncontact surface profiling system (Figure 6) was used to measure the surface roughness. This system utilizes noncontact scanning white-light interferometry for 3D surface configuration. The average roughness value (R_a) of each specimen was calculated. Three tracings were performed on each specimen at three different locations (2 mm from each other along a predetermined line across the specimen). The mean of these values was taken as the surface roughness value. The data were processed using the Vision 64 software (Bruker Nano GmbH, Berlin, Germany) accompanying the Bruker Contour GT-K system [30 (link)].

A sample from each type of porcelain in glazed or polished surface was scanned after KH immersion and thermocycling. The surface topography of six samples was represented graphically via white light interferometry (Contour GT-K1, Bruker Nano GmbH, Berlin, Germany) under 50× magnification with back scan and length parameters of 20 µm in VSI/VXI mode to obtain a 3D rendering of the sample surfaces. Vision 64 software (Bruker Nano GmbH, Berlin, Germany), which is part of the GT-K1 system, was used to copy the surface topography parameters.

Prior to the surface observation, sample surfaces were sputtered-coated with a 20 nm thick gold-palladium. The surface morphology was characterized by using a scanning electron microscope with an energy-dispersive X-ray spectroscopy instrument (SEM-EDS, MIRA4 LMH, TESCAN, Brno, Czech Republic) at an acceleration voltage of 15 kV. The surface roughness was determined by an optical profiler (Bruker Countor GT K 3D, Billerica, MA, USA). Four specimens per group were measured with vertical scanning interferometry with a 1× magnification lens, a field of view of 0.4 × 0.4 mm, and a scan speed of ×1. According to the manufacturer’s instructions, the ‘VXI’ mode was used to reduce the noise level in the flat area. Moreover, the tested areas were 3D reconstructed for visualizing the surface topographies. According to ISO 25178: 2012 [45 ], the height, spatial, and hybrid surface texture parameters were chosen to describe the characteristics of the implant topographies. Based on the surface scales of the craniomaxillofacial implants, the arithmetical mean height (Sa), root mean square height (Sq), texture aspect ratio (Str), and developed interfacial area ratio (Sdr) were selected, as previously reported [46 ]. All parameters were determined and analyzed using the Vision 64 software (Bruker, Billerica, MA, USA).

The surface roughness analysis of the specimens was implemented according to ISO 25178 (non-contact type), which is related to the analysis of 3D areal surface textures. The measurements were performed prior to and after the treatments using a Vertical Scanning Interference (VSI) microscope (Contour GTI 3D, Bruker Corp, MA, USA). One image was obtained (magnification ×20) from each specimen at the four quadrants of each specimen’s surface, corresponding to a surface of 0.317 × 0.238 mm². Vision64™ software (Bruker Corp, MA, USA) was used to acquire the data and compute the arithmetical mean height of the surface (S_a) and the maximum average between highest peaks and highest valleys of the surface (S_z) of each image. The values of the four images of each specimen were averaged and the mean values were calculated.

The surface roughness of the fabricated single lens array with a small physical aperture and a radius of curvature in a sub-µm range is crucial. Although the surface roughness must be below less than 1 nm for high quality X-ray mirrors, the surface roughness required for refractive lens is below 100 nm³¹ . We measured the roughness of the side wall of the fabricated nickel structures with an optical three-dimensional surface profiler (ContourGT, Brucker, USA) using the vertical scanning interferometry (VSI) mode with a green luminous source. The measured area was 130 µm × 170 µm, the average roughness (Ra) of the surface was evaluated to be 36 nm ± 5 nm using Vision-64 (Bruker) surface analysis software.