Is Dentistry Safe and Effective?

The FDA may be too conservative but it does subject new pharmaceuticals to real scientific tests for efficacy. In contrasts, many medical and surgical procedures have not been tested in randomized controlled trials. Moreover, dental care is far behind medical care in demanding scientific evidence of efficacy. A long-read in The Atlantic spends far too much time on a single case of egregious dental fraud but it’s larger point is correct:

Common dental procedures are not always as safe, effective, or durable as we are meant to believe. As a profession, dentistry has not yet applied the same level of self-scrutiny as medicine, or embraced as sweeping an emphasis on scientific evidence.

…Consider the maxim that everyone should visit the dentist twice a year for cleanings. We hear it so often, and from such a young age, that we’ve internalized it as truth. But this supposed commandment of oral health has no scientific grounding. Scholars have traced its origins to a few potential sources, including a toothpaste advertisement from the 1930s and an illustrated pamphlet from 1849 that follows the travails of a man with a severe toothache. Today, an increasing number of dentists acknowledge that adults with good oral hygiene need to see a dentist only once every 12 to 16 months.

The joke, of course, is that there’s no evidence for the 12 to 16 month rule either. Still give credit to Ferris Jabr for mentioning that the case for fluoridation is also weak by modern standards–questioning fluoridation has been a taboo in American society since anti-fluoridation activists were branded as far-right conspiracy theorists in the 1950s.

The Cochrane organization, a highly respected arbiter of evidence-based medicine, has conducted systematic reviews of oral-health studies since 1999….most of the Cochrane reviews reach one of two disheartening conclusions: Either the available evidence fails to confirm the purported benefits of a given dental intervention, or there is simply not enough research to say anything substantive one way or another.

Fluoridation of drinking water seems to help reduce tooth decay in children, but there is insufficient evidence that it does the same for adults. Some data suggest that regular flossing, in addition to brushing, mitigates gum disease, but there is only “weak, very unreliable” evidence that it combats plaque. As for common but invasive dental procedures, an increasing number of dentists question the tradition of prophylactic wisdom-teeth removal; often, the safer choice is to monitor unproblematic teeth for any worrying developments. Little medical evidence justifies the substitution of tooth-colored resins for typical metal amalgams to fill cavities. And what limited data we have don’t clearly indicate whether it’s better to repair a root-canaled tooth with a crown or a filling. When Cochrane researchers tried to determine whether faulty metal fillings should be repaired or replaced, they could not find a single study that met their standards.