“How much tooth do you need for a crown?”

That depends on whether the tooth is broken below the gum line or not. If there isn't enough crown-height for a crown sometimes the tooth needs a "build-up" which will then hold the crown. If the tooth is broken below the gum line sometimes additional procedures like crown lengthening surgery might be recommended. Sometimes, the tooth is in such bad shape that it needs to be removed.

This all depends on whether or not the tooth structure you have remaining is not only enough in quantity but also in quality and location. If there is decay below the gum line or compromised tooth structure in a certain orientation, it makes it very challenging or impossible for your dentist to build that tooth back up again and make it last. Much like renovating or
building a house, you would need measurements and other considerations to decide if you could have a tooth restored with a crown. Your dentist will take X-rays and do these measurements so that you can know for sure before committing to a crown or any other treatment.

Tough to answer without seeing your situation. Depending on the skill of the dentist, as long as the tooth is not decayed or broken below the gum line, it usually can be rebuilt and crowned.

MDSDDS