Some people have good teeth, but their teeth gradually turn yellow or dark as they age. Unknown so! Some people have yellow teeth or tetracyclines, dental fluorosis, etc., so look at the cause of tooth discoloration.
1, physiological tooth color change: Human teeth with age and long-term use, there will gradually change color slightly. Just like your own skin, when you are young, it is white and smooth, and when you are older, you are getting darker. These are all unavoidable. Don’t care too much about such color changes. If you care about your looks, you can use whitening teeth to enhance your appearance, just like skin beauty.
2, exogenous yellow teeth: because the food color paste on the tooth surface, yellow or gray; smoked tobacco, beverages, coffee, tea pigments and other attached teeth are yellow-gray.