[SAump]

The pain went away after you began antibiotics, not the painkillers which only mask the pain. I doubt a blow would cause an immediate infection. If there was infection, there is a tooth problem. Do not wait for the infection to return.

Your dentist should have answered the second question. Now if there wasn't any infection, there is another problem there that may have been caused by a severe blow, followed by clenching of the teeth and muscle strain, and possible tooth pain. But only the expert or followup visit to a dentist can determine the proper way to correct it. Mention it to them before they begin and ask them to explain your options. People choose to have teeth pulled when other options are available and sometimes they refuse the proper treatment when the symptoms disappear.