Hi although you brush your teeth twice daily my concern is that I hope you are doing it the right way! dental plaque
which forms on our teeth everyday is a biofilm and nobody can prevent that from happening. But this plaque has to be effectively cleaned or else it turns into hard deposits called tartar or calculus
which can be removed only by professional cleaning! this what turns your teeth pale and discoloured and causes the mouth to smell bad! please visit a good dentist
nearby and get a check up done also ask him the best methods of brushing your teeth and good oral hygiene practises!