For ingrown toenails, they just cut the nail again as temporary relief. To perminantly fix them, this is the procedure I got:
a) toe gets numbed (first cold spray to numb the skin, then injection of anesthetic to numb the side of the toe for a while)
b) the area of the nail in question is removed, then they apply some sort of chemical to the base of the nail at that location to prevent that part from growing in again.
c) Problem solved