Far too many patients only opt to make an appointment when they are in the midst of a dental emergency of sorts. This is unfortunate, for a few reasons.
The longer you wait between appointments, the longer dental issues have had to fester and worsen. Sticking to your regularly-scheduled appointments allows your dentist to address potential problems, as soon as possible.
Unfortunately, waiting until an oral health issue has become a pressing problem before seeking treatment also tends to mean that it has developed into a more serious matter, which may mean that, not only will it be more complicated to treat, it might also end up being more expensive. (And, perhaps, painful!) And who wants that?
Play it safe and head to the dentist every six months or so!