Some people have naturally yellow teeth. These people do not have a tooth problem. In https://www.randwicksmiles.com.au/yellow-teeth-causes-and-effects/ you can read more about the causes.
Do you know someone who suffers from teeth grinding in their sleep and wants to help you with a cure? If he answered yes, then he is in the right place. Have you lost sleep because sometimes you wake up in the middle of the night when you hear your teeth? Now, do not worry anymore, because when you finish reading, you will sleep deeper and you will have saved your teeth as well.