I am a 21 year old female who takes EXTREMELY good care of her teeth! I have yearly dentist appts. and I brush twice daily. Not much into sugary things, only once in a while.

Today I was smiling in the mirror, just kind of checking out my teeth, and I noticed a GRAY TOOTH, my "eye" tooth. It is a shade of gray that I cannot believe I didn't notice before... it seems to have happened overnight. My boyfriend claims he had noticed it for a while now but didn't want to mention it to me.

What causes this? What can I do? I was thinking about getting ZOOM whitening before I noticed the gray tooth, but now I'm thinking if I get the ZOOM then I am still going to have a noticeably darker shade of "white" tooth!

What are the medical reasons for a good tooth to turn gray, and why do teeth turn gray to begin with?

Very good question but a possibility is that maybe the nerve in the tooth has died which will sometime create that gray hue. This could have been caused by some form of trauma to the tooth ie: getting hit in the mouth, etc. and could have happened years ago. Only your dentist can tell you for sure. And I have to tell you, i have been in the dental field for several years and I would suggest that if you do bleach your teeth, stay away from ZOOM. It is a process that has been touted by "hollywood" dentists as a quick alternative to regular bleaching. The research just isn't out there to support the long term results. With ZOOM the teeth are whitened using uv rays on a blue spectrum which can create enough heat to do damage to tissue. They have to put a gel covering over gums to protect them during these treatments. If it is that dangerous to gums, what is it doing to those delicate nerves inside your teeth? i have attended numerous seminars on the dangers of ZOOM and talked with several people who've had this treatment and ended up with white teeth and increased sensitivity and root canals and dead gum tissue etc... Do it the old way, takes longer (3 weeks) costs less and rarely any side effects. Not to mention that you can control the amount of bleaching so that you may avoid over bleaching.

May I ask, what is the old way of bleaching teeth? You mean something like at-home kits? (I have used those before, and they just didn't get my teeth to the level of white I desired). Can I do a 3-week whitening system that is still professionally given by a dentist?