The surface profile of each specimen was measured before and after the erosion-abrasion cycle with widefield confocal microscopy (SmartProof 5 and ZEN Smartproof HF2 1.0; Zeiss, Oberkochen, Germany). Oriented on the reference markers an 1125 × 4500 µm2 image was recorded with a 10× magnification (C Epiplan-Apochromat 10×/0.4 objective lens, Zeiss, Oberkochen, Germany). The used settings were a fast scan with 150–200 z-levels in mode HDR and low resolution.
Image processing and evaluation was performed with a surface-metrology software (ConfoMap 7.4.8076; Zeiss, Oberkochen, Germany). Before the evaluation the underground was leveled over rotation using a least-square method, furthermore background noise was reduced by removing outliers. Oriented on the reference markers, the surface profile was determined before and after the erosion-abrasion cycle on a specific position of the specimens. Over a superimposition of the both surface profiles, the surface loss was determined from the average height over 0.5 mm in the middle of the specimen. For each sample, a three-fold determination was carried out.
Image processing and evaluation was performed with a surface-metrology software (ConfoMap 7.4.8076; Zeiss, Oberkochen, Germany). Before the evaluation the underground was leveled over rotation using a least-square method, furthermore background noise was reduced by removing outliers. Oriented on the reference markers, the surface profile was determined before and after the erosion-abrasion cycle on a specific position of the specimens. Over a superimposition of the both surface profiles, the surface loss was determined from the average height over 0.5 mm in the middle of the specimen. For each sample, a three-fold determination was carried out.