of;
Prosthetic;
Dentistry,;
School;
of;
Dental;
and;
Oral;
Medicine,;
Cologne;
University,;
Cologne,;
Germany;
for;
Medical;
Microbiology,;
Immunology;
and;
Hygiene,;
Cologne;
University,;
Cologne,;
Germany;
for;
Anatomy;
I,;
Cologne;
University,;
Cologne,;
Germany;
for;
Medical;
Statistics,;
Informatics;
and;
Epidemiology,;
Cologne;
University,;
Cologne,;
Germany;
of;
Pre-Clinical;
Dentistry,;
School;
of;
Dental;
and;
Oral;
Medicine,;
Cologne;
University,;
Cologne,;
Germany;