I know someone who has all grey teeth, she is from a different country, and brushes regularly but have been grey for a long time, is there anything that causes it and can they be white again?

Certain minerals or even lack of minerals in drinking water as a child can cause teeth to be discolored. Also, certain medications can cause discoloration. And then some people just have teeth that are a different color. I would tell her not to worry as long as they have been that way for so long and she goes to regular dentist apts and exercises good dental care. I will say though, teeth that the pulp is infected or died will turn grey. This happened to two of my teeth and I had to have root canals and crowns. The only symptom on exam was the change in color, and the exrays confirmed.

Certain minerals or even lack of minerals in drinking water as a child can cause teeth to be discolored. Also, certain medications can cause discoloration. And then some people just have teeth that are a different color. I would tell her not to worry as long as they have been that way for so long and she goes to regular dentist apts and exercises good dental care. I will say though, teeth that the pulp is infected or died will turn grey. This happened to two of my teeth and I had to have root canals and crowns. The only symptom on exam was the change in color, and the exrays confirmed.

Thank you for the response is there any way to get the teeth white?

Depends on what causes it... age and stains, and even sometimes natural color can be lightened by the dentist either with a laser or at home bleaching. Dead roots require root canals and crowns. Other types of discoloration may require bonding or veneers to cover the teeth.

My sons 2 front teeth were grey and the dentist said it was because he hit his teeth on something. Now they are infected and he had to have them drilled and filled.

I don't know how old your friend is but if they over 40, it could be from taking Tetracycline (antibiotic) as a child. If a child took it before getting their adult teeth, there was a chance of discoloration in the adult teeth. I took it as a toddler and I have mild discoloration. They stopped giving it to children back in the late 60's so it hasn't been a problem since , that I know of.