Can your teeth look clean even when you need a dental cleaning?

I've always found it interesting that you can look in the mirror and think your teeth look perfectly fine while still having plaque or tartar buildup in areas that are difficult to see or clean properly.

That's one reason regular dental checkups and professional cleanings can be useful even when nothing hurts.

For people who are pretty consistent with brushing and flossing:

Do you still get professional cleanings regularly or do you usually wait until you notice a problem?

And what made you realize that a "clean-looking" smile doesn't necessarily mean everything is healthy?