About how long do I need need gauze for after a tooth extraction?

20 to 30 minutes. Just until the bleedding is controlled. Most of the time this will be 20 to 30 minutes.
Atleast 30 minutes. If you do not have any health issue like taking medicine -blood thinners like aspirine then under normal circumstances bleeding should stop in 30 minutes or less.

Related Questions

I'm wondering how long do you keep the gauze in for after a tooth extraction?

I recommend 20 min. The point is to apply pressure on the wound long enough to stop any bleeding. If the bleeding has stopped, then you can remove the gauze but be ver gentle because you do not want to dislodge the clot. Read more...