Dental patients and staff need to be protected from any potential infection by aerosol-generating procedures, the World Health Organization (WHO) said on Tuesday, as dentists return to work in areas where the COVID-19 pandemic is easing. There is currently no data on the spread of coronavirus from the dentist’s chair, it said, calling for more research into common procedures that produce tiny floating particles that may cause infection if inhaled. These include three-way air/water spray, ultrasonic cleaning equipment that removes deposits from the tooth surface, and polishing, the WHO said in new guidance.