Introduction and Aims: The titanium implant survival rate is due to crevicular peri-implant inflammatory mediatiors from immune competent cells in answer to the subgingival biofilm (Salcetti et al. 1996). CD4+ lymphocytes play an important role in periodontitis (Gemmell et al. 2002). In this study the influence of mono-metal titanium (cp-Ti) as being used in dental implants and of two dental alloys (reduced precious alloy (rpa), palladium based alloy (pba) on activation status and migration of CD4+ lymphocytes is evaluated in a 3-D collagen matrix migration model. Materials and methods: After immunomagnetical separation of CD4+ lymphocytes harvested from healthy voluntary donors who gave informed consent were incubated in the 3-D collagen matrix migration model with either titanium or one of the alloys (rpa/pba) mentioned. After time-lapse video recording and digitizing the data were analyzed in respect to cell migration. The activation status of CD25- and CD45R0-receptors was evaluated by flow cytometry. Statistical significance was tested applying the Mann-Whitney U-test Results: Direct contact between CD4+ lymphocytes and alloys resulted in reduced cell migration (rpa:40% reduction, pba: 58% reduction). Titanium led to 11% enhancement (p Schlagwörter: Dentale Implantate, Legierungen, Biokompatibilität, Migration, T-Helferzellen