What Causes Tooth Discoloration | Shareusmile.com
The standard of oral health in the world health organization is: Keep teeth clean, no caries, no pain, natural gingival color. The authorities used to have a tooth whitening survey on workers over the age of 20 in the United States. The results showed that eighty-one percent wish they have white teeth. And thirty-nine percent thought their teeth were not white enough, and willing to whiten the teeth by taking measures. Medically, changing the tooth color (yellow, dark, dental plaque, [...]
