Q. I have had a crown for many years that regularly developed an abscess on the root. The root has been removed and after several months an implant has been inserted but another abscess has developed before it has become established. I am on amoxcillin and metronidazole. It is much better but the gum is still red. My dentist is worried about along term course of antibiotics- now on my third week. How long a course would be safe? and have you saved implants in the past with this problem?