Why does my tooth hurt after a root canal?
In the case of tooth decay progressing to involve the innermost part of the tooth but not destroying the tooth structure to the point where it is beyond saving, a root canal treatment can be carried out by your dentist. Normally, the period of 2-5 days after the procedure is when you are given pain medication to manage the pain that is expected to occur. If pain persists beyond that period, or if the root canal treated tooth starts to hurt soon after this period is over, there are many explanations for why this happens.
What is a root canal treatment?
A root canal treatment involves removing the pulp, which is the core living tissue of the tooth made up of nerves, blood vessels and other cells. The next step is to clean out the now empty root system of the tooth with irrigating agents to make it sterile, then to fill it up with an inactive material to seal it up. If there is enough tooth structure left to support such a restoration, a crown is placed over the tooth to reinforce the tooth structure.
Reasons for pain beyond the normal period after a root canal
If your root canal treated tooth hurts for more than 2-5 days after the procedure has been carried out by your dentist, there are various reasons why this may happen. It is important to understand that you should see your dentist for a follow up appointment to get your root canal treated tooth checked out, in case further dental intervention is required. The different causes for this type of pain are:
- Unresolved infection: In the case of dental decay that requires a root canal, the bacterial infection may have spread to the root tip of the tooth and surrounded the root before the procedure was performed on the tooth. In such a case, while the bacterial load has been removed from within the tooth itself by the root canal procedure, there may still be leftover infection surrounding the tip of the root. This infection will resolve on its own within the span of a few days to a week or so. If your dentist thinks it is required, you will be given a prescription of antibiotics to take in order to help clear up the remaining infection.
- Re-infection of the root canal treated tooth: In the case of a leak in the seal of the root canal treated tooth, bacteria may invade the inner structure of the tooth once again by breaching the compromised seal and once again starting the process of dental decay inside the tooth. The solution to this is to get your tooth assessed by your dentist, who will determine whether repeating the root canal treatment is suitable for your case. In the situation where the tooth structure is decayed beyond repair, your dentist will have to remove the tooth, in which case many tooth replacement options are available.
- Overfilled root canal or trapped air bubble: It may be that in the process of carrying out the root canal treatment, some of the dental material used to fill up the root of the tooth extruded beyond the tip of the root. Alternatively, the treatment procedure may have led to an air bubble being pushed out at the tip of the root. In both cases, you will feel pain that lasts beyond the usual expected duration of post-procedural pain, but it will usually resolve on its own as time passes.
- A bite that is too high: When restoring a root canal treated tooth with a crown, the dentist makes sure to adjust the way the restoration fits with the already existing teeth that it comes into contact with during normal function. One of the causes of feeling persistent pain in a root canal treated tooth is a crown that interferes with the usual way the opposing teeth come into contact with each other, primarily because the crown is too high and the elevated points hit the opposing teeth when you bite down. Fixing this issue is straightforward. You just have to make an appointment with your dentist to further adjust the bite by reducing the high points on the crown of the root canal treated tooth. Once your dentist has made the required adjustments, your teeth should fit normally when you chew, and the pain will go away on its own within a few days.
- Irrigating agent leaking out through the root tip: It may be that during the root canal procedure, the irrigating solution used to remove bacteria, debris and dead tissue from the root canals seeps out at the tip of the root of the tooth. This irrigating agent can irritate the tissues surrounding the root tip, causing pain. Your dentist should wash out the inside of your tooth and place a soothing dressing there, as well as prescribing antibiotics and pain medication to manage the pain as the irritated tissue heals.
- Living pulp tissue left within the tooth after the procedure is completed: The root canal treatment involves removing the pulp from the canals present in the root of the tooth. These canals generally follow a predictable pattern for each tooth, but there may be anatomic variations from person to person. These variations may be extra canals or additional branches of canals that may not be easily detected during the root canal treatment, and therefore missed out from the procedure. When these missed canals are left untreated after the root canal treatment, the tooth remains sensitive to pain, pressure and further bacterial attack. This can be a cause of pain that remains after the root canal treatment is completed. The answer to this problem is to make an appointment with your dentist to have your tooth reassessed to see if it is suitable for repeating the root canal treatment. Then the root canal procedure is repeated to involve the missed canals.
Note to remember
In any case of dental pain that persists after the root canal treatment, do not hesitate to contact your dentist about the problem. Leaving the problem unaddressed can lead to further complications, so the earlier you catch the issue, the better.