Nova Scotia Public Health states, “You should wear a non-medical mask if you have respiratory symptoms (like coughing or sneezing) and you’ll be in close contact with other people, or if you’re going out to access medical care or other essential health services.” https://novascotia.ca/coronavirus/staying-healthy/#masks
In addition, patients are encouraged to use hand sanitizer or wash their hands when entering and exiting a dental office. Further, patients are encouraged to wait outside the dental office or practice social distancing in the waiting room while waiting their turn for dental treatment.
Patients wearing a non-medical mask will obviously need to take it off prior to starting their treatment. In this case patients, should wash their hands or use hand sanitizer immediately prior to taking their mask off.