Would the course of Covid-19 in this country have been different if Medicare had covered routine dental exams and cleanings? Possibly. But the studies have not been done that could tell us with confidence, and they probably won’t be.

Determining cause-and-effect pretty much requires interventional trials. There are so many Covid-related trials going on right now, I doubt that anyone’s going to have time to look into this mess of which-caused-what:

1. Almost 96% of US senior citizens are on Medicare.
2. About 60% of those are on “original Medicare” (parts A and B), with about 40% on Medicare Advantage (part C).
3. Original Medicare doesn’t cover routine dental exams and cleaning. Some Medicare Advantage plans do, some don’t.
4. About 70% of US senior citizens have periodontal (gum) disease.
5. A recent study in Qatar found periodontitis associated with perhaps a 3 to 4 times increase in ICU admission and ventilation for Covid patients. The study claims to have adjusted for “age, sex, BMI, smoking status, and other conditions,” which — if it was properly done — is significant because earlier thinking was that periodontal disease was probably just a common marker for many of the predisposing conditions such as age, sex, hypertension, obesity, diabetes, etc.

We can only wonder: What if Medicare had covered routine dental exams and cleanings? It’s not something I expect to see an interventional trial on; I don’t know how you’d blind it, anyway. It’s possible that a retrospective or observational study of the different outcomes between seniors with dental coverage (mostly Medicare Advantage, although some buy their own) and those without could be enlightening. I’m not optimistic that will happen, either.