It's not just coffee that stains teeth. Adding other substances that humans consume -- be it food or drinks or puff ins; also contributes to teeth staining.
Like I said before: my sister is a strong coffee drinker and she doesn't get her teeth stained.
Check on what lifestyles a person do; and see if there are any other that contributed to the teeth staining factor.
If any of these methods work, and after your teeth are white again, how about you drink coffee through a straw so it doesn't touch your teeth and goes straight into your mouth?
My teeth are as tough as steel (i've always chewed through all candy, including jaw breakers), but consequently, years of stable brushing have not lightened the color of my teeth at all.
-Fix your teeth once and drink coffee through a straw.
- Keep fixing your teeth every time you have a coffee.
Both solutions are pretty easy, it's up to him I guess, although each solution has a minor consequence, the first contributes heavily to getting wrinkles and the second is rather annoying.
Strange. I don't get wrinkles by drinking using a straw all these years for more than two decades. Or maybe I'll get it about five years later? Three years later?