How I deal with the dentist 🧵
It's one place where you have to remain indoors for an extended period of time without a mask. There are ways to reduce risk. It's important to be able to assess risk as well. Here is what I look for.
1/12
It's one place where you have to remain indoors for an extended period of time without a mask. There are ways to reduce risk. It's important to be able to assess risk as well. Here is what I look for.
1/12
Before I go, I ask the following questions:
- do you have HEPA filters in every room?
- do you have barriers between rooms?
Those are the two things I need before I go.
I also ask if they know anything about the ventilation and they usually answer they don't.
2/12
- do you have HEPA filters in every room?
- do you have barriers between rooms?
Those are the two things I need before I go.
I also ask if they know anything about the ventilation and they usually answer they don't.
2/12
When I go, I bring my CO2 monitor and check to see if I can hear the ventilation or check the thermostats to see if they are "on" and not "auto". If they are in auto, I let them know. If the CO2 > 800 ppm, I won't go back.
3/12
3/12
https://twitter.com/joeyfox85/status/1509704366353223681?s=20
The hygienist/dentist/assistant always wear masks. I would prefer N95s, but they often don't. Some people request they wear N95s. For me, I just accept it as a risk that they will wear only surgical masks.
4/12
4/12
Fallow time between patients is good. With good air cleaning, it doesn't need to be long since the rooms are small.
I don't wear a mask over my nose, although some people do it.
5/12
I don't wear a mask over my nose, although some people do it.
5/12
Assessing Risk
I wear a N95 until I get into the operatory. There are two risks for transmission - shared room/close range transmission with the hygienist/dentist/assistant working on you and long range transmission from other rooms.
6/12
I wear a N95 until I get into the operatory. There are two risks for transmission - shared room/close range transmission with the hygienist/dentist/assistant working on you and long range transmission from other rooms.
6/12
For short-range/shared room transmission, the risk is low just because you are exposed to only a couple of people. Chances of them being infectious are likely low.
Graph from @Kit_Yates_Maths . I've added gridlines.
7/12
Graph from @Kit_Yates_Maths . I've added gridlines.
7/12
Even unmasked, the risk from long range transmission is very low. This is because:
1. HEPA filters
2. Barriers between rooms
3. Not an environment where unmasked people are talking a lot
8/12
1. HEPA filters
2. Barriers between rooms
3. Not an environment where unmasked people are talking a lot
8/12
Other unmasked patients are sitting quietly.
On this graph, yellow is aerosol generation from breathing. Pink is talking and blue is singing. Risk from transmission by an infectious person exhaling is generally low.
9/12
tandfonline.com/doi/full/10.10…
On this graph, yellow is aerosol generation from breathing. Pink is talking and blue is singing. Risk from transmission by an infectious person exhaling is generally low.
9/12
tandfonline.com/doi/full/10.10…
If there is descent ventilation, I'm okay with that risk.
Last thing - I don't think personal HEPA filters or personal far-UV will help unless you are holding it very close to your face, so I wouldn't bother.
10/12
Last thing - I don't think personal HEPA filters or personal far-UV will help unless you are holding it very close to your face, so I wouldn't bother.
10/12
https://twitter.com/joeyfox85/status/1594780393785462790?s=20
Summary:
- low probability that the hygienist/dentist/assistant is infectious
- I require barriers between rooms and HEPA filters
- I check ventilation and won't go back if it's bad
- low risk of long range transmission because other people aren't talking
11/12
- low probability that the hygienist/dentist/assistant is infectious
- I require barriers between rooms and HEPA filters
- I check ventilation and won't go back if it's bad
- low risk of long range transmission because other people aren't talking
11/12
Additional measures you can take:
- ask the people working on you to wear a N95
- wear a mask over your nose
- ask about fallow time
Everything involves risk. I educate where the risks are, how to mitigate and let people make their own assessment.
12/12
- ask the people working on you to wear a N95
- wear a mask over your nose
- ask about fallow time
Everything involves risk. I educate where the risks are, how to mitigate and let people make their own assessment.
12/12
• • •
Missing some Tweet in this thread? You can try to
force a refresh
