I've heard of skin makeup, but have you seen makeup for your teeth?
Found them in a shop in Sydney and they all have different properties. You can have it looking natural, extremely white and invisible.
The brush is similar to those nail polishes and it even has a small round mirror on the bottle so that you can see it when you apply. It is meant to be applied to your front teeth where it is the most visible for all to see.
Extremely useful for those who teeth are a little yellow and would like to brighten it up before a night out/interview.