To improve osseointegration, different possible dental implant surface modifications, e.g., alterations of surface chemistry and roughness, have been developed. The purpose of this study was to examine the in vitro biocompatibility of newly designed zirconium implants with different surface modifications in comparison with commercially available zirconium and titanium implants. Therefore, cell viability and proliferation were measured after 21 days and correlated with surface structures. In the presence of new ceramic implants with an "mds (blasted/etched)" and a "blasted" surface, cell viability was 1.29- and 1.26-fold increased, respectively, compared to untreated cells, whereas cell viability was unchanged in the presence of reference implants and new ceramic implants with an "etched" surface. The cell viability findings correlate with the results of the cell cytotoxicity assay. The etched implants showed a surface with high roughness and heterogeneity, whereas the mds and blasted implants showed a similar, very rough-textured homogenate surface. The in vitro biocompatibility of two new ceramic implants was significantly better in comparison with the tested reference ceramic and titanium implants. The good biocompatibility may be attributed to the homogenous surface of these implants, and these surfaces might hasten osseointegration.