My child had a front tooth chipped and the composite used in the repair came off within a few months. I understand that a composite repair is not as permanent as a veneer but that it should hold for up to five years. The same child had a cavity filled in a baby tooth and it bothered them until the tooth fell out. I'm not a dentist but I could see in the tooth that fell out that the composite filling did not completely fill the cavity, which it seems to me was most likely why there was pain.
On a better note, an emergency was handled quickly and compassionately, and the hygienist named Barbara is extremely good at her job. She is actually the reason that I stayed as long as I did after this dentist purchased the practice when the previous dentist retired.