Teeth have varying anatomical differences and sometimes have additional canals. Occasionally, these are not found during the initial treatment, leading to treatment failure and necessitating retreatment later on.
In the video below, I present a case I handled several years ago while I was still an intern. Unfortunately, it was not a properly executed treatment:
- Lack of proper preparation for treatment
- No isolation of the surgical field
- No work under magnification
- Improper reconstruction of the tooth after treatment
Fortunately, after some time, the patient returned to me once more. This time, however, I was prepared and knew much more about root canal treatment.
When performing retreatment, the dentist must treat all the canals again (even if previously three out of four canals of a tooth were treated). The canals are interconnected, so there is a possibility that one untreated canal transmitted bacteria to the other three.
Before retreatment, the dentist first removes the previous filling and then rebuilds the tooth for treatment.
Next, the dentist prepares and widens the canals.
Premolars have one to four canals.
Molars have a minimum of three canals.
Sometimes these canals are fused, for example, into two wider canals. In molars, there can be as many as 6!
Canines and upper incisors usually have one, but two-canal canines also occur.
Lower incisors typically have 2 canals.
Effectiveness of Root Canal Treatment
First-time root canal treatment (done well) has an effectiveness of about 90%
Retreatment has only 60-70% effectiveness.
Nevertheless, it is better to opt for retreatment than to lead to extraction.