Validation of three-dimensional surface characterising methods: scanning electron microscopy and confocal laser scanning microscopy.
Surface characteristics of enosseous titanium implants have been known to influence the quality of osseointegration. Parameters recommended for metrical analysis should be supplemented by a topographical description. In this study, Ra values obtained by established tactile and optical profilometric methods are correlated with those obtained by stereo scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). As test specimens, standardised CVD diamond-coated titanium alloys with different microwave coating power ranging from 2,000 to 3,000 W were used. A non-CVD-coated corund grit-blasted specimen (NC) was used as reference. After coating with a CVD, power of 2,000 W Ra ranges from 4.33 to 5.69 microm depending on the method used. With increasing power of the coating process, the amplitude of the surface roughness is significantly increased to 4.53 to 6.89 microm. Ra values of the same sample obtained by different methods are also significantly different (p = 0.001). Compared with the established methods of tactile and optical profilometry, SEM and CLSM offer valid data on the surface roughness accompanied by a topographical imaging. In future studies, the underlying method should be specified to interpret roughness values correctly, as not every method is suitable for each specimen and values obtained by different methods vary extremely.