22| Biomaterials Product catalog 2021 Science It's the cells that make the decision Functionality of biomaterials results from their optimal biological interactions with tissue cells. Bone is a structure difficult to duplicate. Research in tissue engineering, especially in nano topography, can lead to improved biomaterials. There are numerous biomaterials available, some of natural origin, others of synthetic origin. When choosing a biomaterial, many factors come into play next to functionality. From a biological point of view, the ideal biomaterial should promote formation of a stable blood coagulum. It should be functional, biocompatible, and it should favor healing processes. Autogenous bone is still the gold standard in grafting. However, it is linked to higher costs, longer treatment times and it requires an additional surgical procedure possibly leading to increased donor site morbidity. This needs to be considered when carrying out augmentation procedures. Therefore, the possibilty of reducing potential complications is an important factor. Easy handling of the materials is of advantage for the clinician. Aside from these decisive factors, it must not be forgotten that bone augmentation surgery is often performed as a part of dental implant surgery. Therefore, different biological aspects should be considered when choosing biomaterials. Comparative studies have shown that different biomaterials can be safely used . The needs and preferences of the treating clinician play as important a role as the indication, the requirements of the patient, as well as time and costs. In the end, selection of the appropriate biomaterial must be made with the knowledge of its properties and its clinical outcome. The goals are always predictable results and clinical success. Conclusion: Prior to using a biomaterial, it is recommended to balance and consider the biological interaction between the biomaterial and the endogenous cells  – it’s the cells that make the decision.