Question: I am overdue for dental cleaning. Over a year since I cancelled last fall with my shattered ankle. I have concerns about our #1 hygienist who had Covid in June, recovered, but now wears her mask UNTIED … hanging from her ears. No shield. Should I pick another more buttoned up hygienist in the office?

Answer: We talked about dentists and risk way back in our Q&A of July 11.  Since then, CDC’s guidance for dental settings has been updated, and now includes the recommendations regarding eye protection in addition to mask protection (copied below).  Because your hygienist is not following hygienic practices, I recommend finding another one.  I also wonder why the dental practice allowed the hygienist to flout the rules.  What’s going on with the practice overall?      
A few more thoughts:

• We don’t know how lasting immunity is from coronavirus infection. This gap in knowledge means that we do not have certainty about whether/under what circumstances a person who has contracted COVID-19 once can get it again.  We now know that it is possible, with a few documented case studies of true reinfection (see Q&A of 10/14).  Note: possible and probable are obviously not one in the same.
• Because masking has not been a fully adopted social/behavioral norm, it is important for community leaders, health care providers, family members, friends, and more to model the behavior as an important avenue towards changing social norms. (if you’re interested, brief descriptions of social behavior change theories are here)   
• Masks are protective not just against COVID, but against other viruses transmitted through respiratory drops and air.  Even if your hygienist were immune to COVID, she’s not immune to a host of other viral pathogens.  

Excerpts from CDC’s Guidance for Dental Settings

 Dental healthcare personnel should wear a face mask or cloth face covering at all times while they are in the dental setting, including in breakrooms or other spaces where they might encounter co-workers.” [emphasis CDC’s]…

In areas with moderate to substantial community transmission, during patient encounters with patients not suspected of SARS-CoV-2 infection, CDC recommends that dental healthcare personnel:

Wear eye protection in addition to their facemask to ensure the eyes, nose, and mouth are all protected from exposure to respiratory secretions during patient care encounters, including those where splashes and sprays are not anticipated.

Use an N95 respirator or a respirator that offers an equivalent or higher level of protection during aerosol generating procedures.