“How much tooth should be left for a crown?”

At least 50%

A tooth is prepared for a crown. It is "shaved" down on top of the tooth and all sides. Enough tooth structure must be removed to have sufficient thickness for the crown. Generally speaking at least 1.5mm to 2mm must be removed.

Hello,

Wow, this is an incredibly astute question! Dentists can do some amazing things with teeth. Most people see teeth as being small and when they get drilled there is nothing left. However, dentists see a lot more than that. As a matter of fact, putting a crown on a tooth today is more a matter of convenience and desire than how much tooth is left.
Yes, there are rules to how much tooth needs to be there for a crown, i.e., 4mm of height is usually quoted in text books, but there are a lot of other factors that go into this. Textbooks will also talk about the ferrule of a tooth needing to be at least 1.5mm as well. However, there are plenty of times that a tooth is broken off at the gum line and we can still put a crown on it. It is a matter of knowing the rules and knowing what is important. Speaking of "knowing what is important"; just because we can put a crown on a tooth does not mean that we should. There are plenty of situations where we can create more tooth (crown lengthening procedure), do a root canal, put a post in the tooth, build it up, then put a crown on it. However, with the success of implants, more people are choosing to remove the tooth and put an implant in (implants are titanium and porcelain, they don't get cavities). The implant is usually the same cost or cheaper and it does not decay. If a dentist is suggesting a crown, there is usually enough tooth left to have a crown. Otherwise, the crown won't be able to go in. This also relies on the dentist abilities as well.
Hope this helps.

My best to you!

William F. Scott IV, DMD

If the tooth is vital, nerve is intact, at a very minimum 2 mm of stable tooth structure above the gum line. This means that 75 % of the tooth structure is gone. If any more is gone then a root canal is advised so that I reinforcing post and core can be utilized. The technical skill of your dentist and fabrication process of the crown are the most important factors involved

When I prepare a tooth for a crown, usually requires 1.5 to 2 mm of tooth reduction throughout top/sides so the porcelain/gold or zirconium has appropriate thickness so as not to fracture upon mastication.

The more the better, teeth can still be restored even when they are just 1 or 2 mmm above the gums, assuming no caries are left, aRoot canal treatment and a build up of the tooth can proved enough space and strength to pace a crown. A surgical procedure can be performed to get access to more tooth. Check with you dentist or ask for a referral to a specialist. Cheers

A dental crown requires enough tooth structure so when the crown is on the tooth without cement, it is not loose ! needs parallel walls, retention, and of course the more tooth remains the better it is. Note that for dental crown the preparation by the dentist is the full circumference of the the tooth vs dental veneers. For more on crowns, click here: https://celebritydentist.com/porcelain-crowns/

As much as possible.

If the tooth is so broken down that only a little piece remains, it's possible that the tooth is not big enough to hold a crown in place. Also, if the tooth is broken down under the gum line, this can sometimes be a case where the tooth is non-restorable. Ultimately, this is something you need to discuss with your general dentist so they can evaluate and create a treatment plan accordingly.