How long does the tooth extraction injection pain last?

A few seconds: The pinch from the needle vanishes almost instantly as the injection starts to take effect.

Varies: The pain at the injection site is caused by trauma to the area. Although it is usually transient, it can last up to four or five days. If the numbness has persisted this long, get back to the practitioner who gave you the injection and let him examine you immediately.

The injection: Discomfort is minimal and typically is not an issue. Depending on the extraction , the post-op pain can also be minimal. I'm sure your doctor will prescribe appropriate medications to keep you comfortable. Hope this helps.