Dental Clinics are opening up in Toronto again this week for non-essential services.
However, dentists are required to wear N95 masks. For that, they have to have a fit test. In order to pass this test, they have to shave their beards or keep a French beard.
The other option is to wear a respiratory mask but with that they can't wear the loupe which they need to examine the mouth.
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
The Islamic ruling in regards to the beard is quite clear. Shaving or trimming the beard in light of the Sunnah is strictly forbidden. When one takes on such professions one should be very mindful of the upholding of Islam and its teachings.
The hadith mentions clearly that the Prophet (peace be upon him) said, “No obedience is allowed in the disobedience of the creator.” 
In regards to the above question, there are certain health organizations that allow for the dismissal of certain practices based on religious needs. One should contact the department and explain to them the Islamic and religious perspectives of the beard.
Only Allah knows best
Written by Maulana Irfan Ali
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham