Unless yellowing teeth are simply due to the aging process, there can be a number of reasons why teeth can turn yellow or become discoloured. The obvious candidates that lead to discolouration include:
– Coffee, tea and red wine
– Genetic predisposition
Heavily stained teeth require a professional cleaning which “can remove most surface stains” but taking good care of the teeth and regular check-ups at the dentist is the best way of avoiding or minimising the problem.
Daily brushing and flossing is vital in preventing plaque and bacteria accumulating which leads to yellow teeth and more information can be found at https://yourdentalhealthresource.com/why-are-my-teeth-turning-yellow/