What makes my yellowish teeth look white? any toothpaste/ any medication/any home therapy

Few reason...: Your genetic make up, your diet, along with your oral hygiene will generally determine how yellow your teeth color will be. There are also some medications (tetracyclines...Even if your mom took it while pregnant! that can alter the inner color of all your teeth, (but mainly to brownish/grayish tone) . Also many teeth turn dark after a root canal therapy. Generally "bleaching" is the treatment.

Teeth whitening: Custom trays, home bleaching/whitening system will give you the best results. The system is available trough the dental office that will fabricate the trays, provide you with professional strength bleach and monitor results. Otc bleach and whitening tooth paste could be used as a supplement.

Bleaching: Make sure there are no cavities use Fluoride to offset sensitivity.

Teeth Whitening: There are different options to whiten yellow teeth. The in-office whitening treatment is quickest and provides the best results, about 4-6 shades whiter in about 1 hour. The other is in-home treatments. These need diligence and persistence to attain visible changes. Due to the possibility of sensitivity and irritation of gums, it is recommended that you visit a dentist for a full consultation.