I had the same problem, I had an old silver filling that got chipped and started falling apart, I had no pain whatsoever, so I kept putting it off, to get it refilled, I waited approx. 2 years, and then it did start hurting, and by the time I went to the dentist it had turned into a root canal. So don't wait on getting the old ones out and new ones in because you have no pain, because it will eventually turn into a root canal.