How long does a temporary crown last after a root canal?

Not Long: The tooth becomes brittle after a root canal and a final restoration is highly recommended. Not getting the final crown may be playing with fire. I have seen well done root canals fail under a temporary crown in less then one year.

A few weeks!: A well made temporary should last a few weeks but the root canal treated tooth might goes bad due to leakage after a month or two. You should have a permanent filling as soon as possible after root canal.

Not very long: It is very important to get the permanent crown on a root canal treated tooth as soon as you can. These teeth are very susceptible to breaking down and need the coverage to provide strength. You don't want your investment of time and money in the root canal to be wasted.

Short time period: The temporary crown is usually made of acrylic which is a weak material. Hence the crown last a short time, hence the name temporary. See your dentist soon to have a permanent one made.

Don't delay. : They aren't designed to last very long. Although the crown may function, the "seal " of a temp crown can be washed out, therefore your saliva will penetrate the root canal seal and cause it to fail.