What's the secret for white teeth? : AskReddit: "I have a lot of expertise on this. I run a teeth whitening brand.
There are 2 kinds of stains, outside & inside. Enamel is clearish-gray, but stuff can stick to it, very nearly all whitening toothpastes just work on this, they scrub the outside with 'hydrated silica' (sand!). This is also the reason your teeth feel so nice after being at the dentist, because they use aluminum oxide (far more abrasive) and really grind your teeth clean.
The second kind of stain is at the core, because enamel is clearish, the calcium 'dentin' layer shows through. It can yellow from the foods you eat, medicine, age, etc. The key is that it does not come from the surface, and you cannot brush it away. The only thing that gets it clear is peroxide, it can leech through tiny holes in the enamel and chemically bleach the core.
The secret for whitening is peroxide, and the formula is simple: Whitening = (amount of peroxide) X (how long it is in contact with your teeth) X (how many times you apply it)
You can go hardcore mode, and do a 2 hour kit or dentist treatment which gets you a lot of peroxide and a shorter time. You can go with middle of the road and do strips for 1-2 weeks, or you can go with daily and use a paste that has active peroxide in it (calcium peroxide is inactive, does not work), so you're getting a small, low dose every day.
My personal reco is to hit it fast with a 2 hour kit, and then use peroxide paste for a while to keep whitening & maintain it.
To my knowledge, the only pastes with peroxide is Luster or Rembrandt Plus Peroxide (mine).
One last point - you see a lot of treatments now that include some kind of 'UV light'. Fuck that shit. It's nothing to do with the light. The light produces heat, and heat makes peroxide work very slightly faster. You won't get anything with a light that you wouldn't get by wearing the treatment you're using for 1 or 2 minutes more.
