When decay in a tooth is left untreated, the bacteria causing the decay will eventually reach the nerve in the centre of the tooth and infect it.  An infected tooth nerve can be extremely painful. After the infection has killed the tooth nerve, the pain momentarily disappears. It is not unusual for patients to be able to tell us the exact time the tooth nerve died, as the pain goes from 9/10 to almost nothing.  The infection then continues to spread into the jaw bone, with a slowly increasing debilitating pain.

Antibiotics will provide short term relief, but are ineffective in treating the infection as the infected tooth becomes a constant seed of infection into the jaw bone.
Left untreated an infected tooth can result in a severe facial swelling and sometimes hospitalization.

To treat the infection, the bacteria inside the tooth need to be washed out and the tooth filled with antibiotics to disinfect the area.  Once the body has shown signs of healing, the antibiotic dressing is removed and the tooth root canal is sealed to prevent reinfection.  This process can take between 2-3 appointments.  Although root canal can be performed in a single appointment, the chance of reinfection is greater.