Since 2019: Professor for Periodontology (Kuwait University) 2016-2019: Professor for Periodontology and Msc course director (MBR University, Dubai), MSc Program Director (Sharjah University) and Consultant Specialist Periodontist of MOH-UAE Since 2012: Expert for Oral Implantology (DGOI) 2011-2016: Professor for Periodontology (Catholic University of, Rom, Italy) 2006-2011: Apl. Professor for Periodontology (University of Mainz) 2004-2006: Associate Professor (PD; University of Mainz) 2001-2004: Associate Professor (PD; Freie Universität Berlin) 2000: Focus of treatment in Implantology (BDIZ) 1999-2004: Adj. Professor of Periodontology (University Buffalo, USA) 1999-2000: Post-doc studies in Oral Implantology (DGZI / University of Göttingen) Since 1998: Specialist for Periodontology (DGPARO) 1995-1999: Clinical Associate Professor (University of Buffalo, USA) 1993-2000: Associate Professor (PD) (University of Witten / Herdecke) 1993-2016: private practice limited in Periodontology/Implantology and Implant-Prosthodontics in Düsseldorf 1991-1995: Vis. Clinical Associate Professor (University of Buffalo, USA) 1991-1993: Education in Perio-Implant-Prosthetics (RWTH Aachen), Associate Professor (PD; University of Marburg) 1991: Habilitation in Periodontology (University of Marburg) 1985-1991: Specialty training in Periodontology (University of Marburg) 1984: PhD (University of Athens) 1982-1985: Clinical training in Operative Dentistry and Periodontology (University of Saarland) Since 1982: German licence 1980-1982: Post graduate Studies "Preventive dentistry" (University of Athens, Greece) 1974-1979: Studies of Dentistry (DDS; University of Athens)