How much tooth has to be left for a filling to work? i have a tooth that almost cracked in half. i'd rather get a filling than a crown, but i'm not sure if there's enough tooth left for a filling to work.

New : New york, i can build an entire tooth out of filling material, but it won't last. You can almost always get a filling rather than a crown, but not the best of ideas. It can save you some money in the short run but cost you a lot more in the long run including the loss of your tooth. Hope that is helpful, michael i. Wollock, dmd, agd fellow dentistry at suburban square 610-649-0313 www.Dentistryatsuburbansquare.Com.

As : As the other panelists have explained, fillings are designed to fill a hole, not restore an entire tooth. The material is not strong enough. As an aside, the explanation that i give my patients is this: you need the right materials to get the job done right. Hope this helps.

There : There is no special amount, number or percentage of tooth structure necessary to support a filling. See a dentist to discuss your options intelligently (bonded filling, inlay\onlay, crown, extraction).

Generally : Generally speaking, the more tooth that remains, the more stable the restoration will be, and the longer it will last. If more than 60% of the tooth is compromised, or if one or more cusps are unsupported (weak), your dentist may suggest placing a crown on the tooth.

According : According to your description, a tooth half cracked would be better restore with a 3/4 porcelain crown or a full porcelain crown, in today's dental advances such as "cerec technology", it's easier and more predictable to restore a tooth with an unprecedented accuracy. Please find a dentist in your area who's proficient with the cerec restorations, and in one short visit you will have your tooth fully restored with the most durable material available in dentistry, 'pressed porcelain ' good luck.

Get a crown: You should at a crown as an exotic filling when a more conservative filling can't be used. The bigger the filling the more the likelihood that the tooth may fracture and then possible need more expensive dentistry or possible extraction.

Variable: If there is that little tooth structure left, it would likely be better to have a crown done - if you are asking which would last longer.

Depends: Whether a filling works and how long it lasts depends on the amount of tooth remaining, which tooth is involved, and how your bite interacts with the filling. Almost any tooth can be restored with a bonded filling, but this may not be viable as a long term solution. Your dentist can give you a better answer based on an examination and x-rays.