How long should I be experiencing pain that requires percocet after oral antral communication surgery?

A few days. I would expect typical pain from a procedure like this to abate after 4 to 7 days, but we each have our own pain threshold! some people require no narcotic pain meds for surgery like this, but others might need Percocet for 10 to 14 days. Be sure to let your doctor know if you need a refill, as this medicine can't be phoned in- a written prescription is required.
Couple of days. First you might try a NSAID like Ibuprofen or aleve.This class of drugs is much more effective for oral surgery than even the opioids lke percocet. If bleeding is a concern and you are not allergic to sulfa drugs you might ask about Celebrex (celecoxib) which doesn't have a bleeding problem.