SARS-CoV-2(29) COVID-19(23) clinical(18) Patient(18) Result(16) objective(16) material(12) SARS-COV-2 infection(12) pandemic(11) coronavirus(9) infection control(8) subject(8) supplementary material(8) Aerosols(8) examined(8) Germany(8) measure(8) COVID-19 pandemic(7) risk(7) lockdown(7) dentistry(7) Protective(7) indicated(7) significantly(7) RT-PCR(6) performed(6) increase in(6) Effect(6) positive(5) Laboratory(5)