HOW TO GET WHITER TEETH

My mum says that I have got yellowish teeth. No I don't smoke. Never have and never will. I think I have naturally yellow teeth. Furthermore, I don't think I will go to the dentist to get them whitened either.
I read that if we eat an apple we can whiten our pearlies. It seems that the
crunchy fruits and vegetables act as little toothbrushes when we chew them; they have a natural cleansing action that works on tooth enamel to remove stains. Apples in particular have a gentle malic acid that also helps dissolve stains.

SOURCE: http://health.msn.com/nutrition/slideshow.aspx?cp-documentid=100249904&imageindex=10