Unless the nail root cells growing the nail are destroyed, the nail will always continue to grow in.  In many cases, painful ingrown toenails either temporarily calm down on their own or are treated by general doctors and emergency room physicians when they become painful and infected.  This treatment includes soaking the toe and taking antibiotics, or simply cutting the nail corner back.  These measures will help to reduce the skin infection next to the nail, but the nail remains ingrown.  Even if the entire side of the nail is cut out by one of the above doctors, unless the nail root cells are destroyed, the new nail will eventually grow out again with the side still ingrown, starting the process all over again.