Why can't porcelain veneers and crowns be bleached?

Answer 1

The brightness of a tooth is a function of how light is reflected off the enamel. Whitening agents work by dehydrating the enamel, that is, by removing moisture on a molecular level from within the enamel. This increases the amount of light that is reflected off the tooth, and therefore it makes them appear whiter. There is no indication at this time that this is harmful to the teeth in the long term, however, some people will experience an increase in temperature sensitivity when they whiten their teeth. Porcelain crowns and tooth-colored fillings do not bleach because the agents cannot remove moisture from them as they do with natural enamel. Over time, the moisture will return to the enamel, and the whitening process will have to be repeated to maintain the new whiteness of the teeth.

Answer 2

Not all teeth whiteners work per se; unless a teeth whitening treatment is done by a professional. However, if you are pertaining to over-the-counter teeth whiteners then intense research should be done first before trying out the product. Cheap otc teeth whiteners are usually dangerous since the chemicals used to whiten teeth are of low quality. Another factor that will justify whether a teeth whitening "works" is it's longevity. Most otc whiteners would only last for a short time; as far as I there are products that would last for 6 months and less.

Answer 3

They aren't porous like natural teeth which have 'rods' that the tooth breathes with.

Answer 4

it hasn't mine