I bet the worst medical advancement or study result for dentists would be the one that definitively shows six-month checkups aren't better than annual.
It depends on the person and the chemical makeup of their mouth in conjunction with their brushing and flossing habits.
Some people can be fine even if they go years between checkups. Other people like me need to go three times a year even though I brush and floss every day.
Gee, I wish someone would study why I need to go three times a year and maybe figure out how to change the chemical makeup of my mouth so I didn't have to!
People are too profitable for the system to be motivated to figure out actual causes behind common problems.
Your quip reminds me of a comment from 2 weeks ago, where someone shared how vitamin K supplementation helped reduce buildup on their teeth: https://news.ycombinator.com/item?id=20902899
I understand that people usually get adequate Vitamin K2 from their intestinal bacteria. Perhaps the buildup on your teeth is due to your microbiome.
I brush with salt and baking soda, but still have some plaque on my occasional visits to the dentist. I’ll have to think about this some more.