> 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!