This systematic review aimed to investigate the COVID-19 biological risk based in knowledge, attitudes and perception of dentists during COVID-19 pandemic and to establish a clinical protocol based on the literature. The protocol was conducted in accordance to PRISMA Statement and registered on International Prospective Register of Systematic Reviews (CRD42020200258). PubMed, Embase and SciELO were systematically searched, using the key terms "coronavirus infections" AND "dentists". Four articles were selected for qualitative and ten for quantitative analysis. The overall studies reported characteristics of dentists (n = 12,913) who completed survey questionnaires: male (n = 6,690; 51.8%); knowledge: transmission route (n = 1,892; 14.65%), use of personal protective equipment (PPE) (n = 2,418; 18.7%) and signs and symptoms (n = 1,489; 11.5%); attitudes: urgency treatment (n = 2,633; 20.4%), handwashing (n = 5,548; 43%), reducing patients in waiting room (n = 3,020; 23.4%), and use of masks (n = 4,068; 31.5%); and perception: infection risk (n = 2,387; 18.5%). The clinical protocol includes procedures before appointments, correct handling of the operative area, and use of correct PPE. The primary COVID-19 biological risks are infectivity and horizontal transmission. The clinical care protocol in dentistry should be adopted by all dentists to reduce biological risk. Thus, dentists may play an important role in the prevention and interruption of SARS-CoV-2 transmission chain.