Biomaterials are materials that interact with living tissues in a biological system and support or replace their natural functions. An effective development of biomaterials with specific functionalities and optimal biocompatibility demands a thorough understanding of their individual properties (e.g. topography, roughness, wettability, mechanical strength) and relationships. This results in increased requirements for appropriate characterization methods and analysis techniques.
In the present research, first approaches are demonstrated to extend our measurement and analysis methodologies for effectively predicting, defining, and controlling roughness structures for optimal hygrophobic and hygrophilic wetting properties to biomaterials. For instance, surface structures with well-defined roughness characteristics in the micro- and nano-ranges are of crucial importance for functional surface properties. In contrast to common parameters like rms-roughness, a description by Power Spectral Density (PSD) functions based on optical and non-optical measurement techniques provide advanced quantitative roughness information: PSD functions yield data about the vertical as well as lateral distributions of the roughness components. The combination of PSDs obtained from different scan areas and different measurement techniques enables a roughness analysis over a wide spatial frequency range. The same applies to the wetting behavior: A description by simple apparent contact angles is only sufficient for a first assessment. But a suitable evaluation and comparison of the specific wetting properties requires characterization methods that are well defined and focus on the particular application.
Examples for a comprehensive roughness and wetting analysis are given for biomaterials in dental application.