Well that's ironic

That just means your dentists dentist sucks. He can't fix his own teeth. Besides the normal brushing and stuff..

Irony!

OP doesn't have the word space to say whether by "bad teeth" they mean teeth that are simply a bit off-white and slightly crooked but not unhealthy or teeth that are bright and straight but are riddled with gum disease. If its the former, I'd say he has his personal teeth priorities right and would be a better dentist than the latter. That being said, I remember once as I suffered from an ED, being referred to a dietician that was very overweight. Of course I was never going to take anything she said seriously and I think that's what it comes down to; in certain professions, you HAVE to take care of yourself because you are a representation of your profession. Even if you obviously cannot perform complicated dental work on yourself, your teeth are the first things that show the pride and diligence you take in your job. A plastic surgeon, for instance, cannot perform surgery on themselves but I'm not going to pay to have my body altered by someone happy to sport a lopsided boobjob.

Bad sign

He might have some sort of condition that he cant control, even though he is a professional and all.

That's like the riddle about the two barbers. It's probably a good thing!

Maybe he just didn't and may still not get good dental care. Not all people can afford it no matter what they do.

my dentist's teeth are more yellow than most dentists because he is a holistic dentist and doesn't believe in teeth whitening or bleaching. your dentist may still have healthy teeth just not pretty teeth.

Sounds like my grandpa! He had rotting teeth (literally) but was an excellent dentist.