question: Had routine "old" cavities replaced in late April.  Very tender/sore gum near one tooth.  Had it re-check a few weeks later.  Dentist performed xray on affected tooth and found nothing. Said my bit was off and did some routine filing of the tooth and said it would be better in a few days.  This week my gum is sore, tooth is sore, cheek is swollen and slightly bruised and I woke up with a small white head on a bubble atop the affected tooth