Yellow stains on teeth may be caused by food debris, calculus, fluorosis or tetracycline, etc. They can be removed by brushing, rinsing, ultrasonic cleaning, sandblasting and bleaching on time. 1. Food debris: insist on brushing and rinsing your teeth after meals every day for 3-5 minutes each time, so that you can clean the food debris and soft scale on the surface of your teeth. 2. Dental calculus: (1) Ultrasonic cleaning of teeth, through high-frequency vibration to remove yellowish-brown tartar on the surface of teeth and a large number of tobacco and tea stains. (2) Sandblasting: Scaling teeth with pearl salt and high-pressure water. When ultrasonic scaling, it can only shake down large pieces of tartar in the mouth, while sandblasting can remove dirt, dust and food stains on the surface of the teeth. Sandblasted teeth are very smooth and do not re-sediment easily. 3. Fluorosis or tetracycline: Some fluorosis or tetracycline teeth will have yellowish-brown plaque on the tooth surface, which should be whitened or bleached with bleaching agent. If yellow stains on teeth affect the aesthetics, they can be removed by the methods mentioned above, and you must follow the advice of a professional doctor.