My mum has got an infection under her front tooth crown. It has been drilled and cleaned 3 times during 3 separate appointments over 10 days in preparation for root canal but the infection is still there. Dentist said oral Antibiotics not necessary. She can taste pus coming from the front of the tooth. She frequently rinses her mouth in salt water but she is waiting for her dentist to call her back tomorrow to arrange another appointment. Does this sound right? I feel she should on oral antibiotics.