Hello my dear friend @drbehram

If you smoke regularly, your hands will turn yellow. Nicotine in cigarettes causes teeth to turn yellow. So quit smoking.If you are in the habit of consuming bean, jorda, tobacco, mouthwash, give it up. It completely destroys the white color of the teeth. Red wine destroys the whiteness of the teeth. Excessive drinking of coffee, soda drinks stains the teeth. So drink in moderation.Eating too much sugar or sweets can change the color of teeth.i wish you success
Best regard @jannatmou