Surgeons and nurses performing clean surgery wear disposable face masks. The purpose of face masks is thought to be two-fold: to prevent the passage of germs (large droplets) from the surgeon's nose and mouth into the patient's wound and to protect the surgeon's face from sprays and splashes from the patient.
CV19 droplets (very small)easily pass through normal masks (surgical, cloth, etc)... only N95 masks have shown ability to reduce, not eliminate, CV 19 droplets.