How does a dentist determine when you need a root canal?

6 Comments

1. Nebula D says:

   July 5, 2010 at 7:37 am

   I’m a dentist.

   My God! The misinformation!

   Endodontic therapy ("endo" for short, more commonly known as "root canal" therapy) is performed for three reasons: an irreversibly inflamed pulp, a necrotic tooth, or electively for restorative purposes. I can’t think of any indications for endo that don’t fall into one of these three categories.

   I’ll spare you the details about the dental pulp (having sat through multiple sleep-inducing lectures about it in dental school, I can tell you for sure that it’s not particularly relevant to your question). Basically, your pulp can become inflamed like any other part of your body. This "pulpitis" can occur from trauma or infection (such as that it would experience from a deep cavity). There may be other rare reasons for which it can occur, but trauma and infection cover 99.9% of the occurrences.

   Pulpitis comes in two flavors: reversible and irreversible. In all honesty, I don’t remember much about the pathophysiologic differences between the two, but I do know that reversible pulpitis is an inflammatory state that typically improves–i.e. there is no significant insult or damage to the pulp that cannot heal with time. Irreversible pulpitis, on the other hand, is indicative of a pulp that is basically "sick" to the point where it is going to die. In such cases, the inflammation is severe, and because the tooth is a rigid structure, the inflammation creates pressure inside the tooth that creates severe pain and as I understand it aids in the death ofl the pulp.

   Reversible pulpitis is characterized by cold sensitivity (and sometimes heat sensitivity) that is mild to moderate and disappears once the stimulus is removed. Tenderness to pressure is usually absent, but sometimes tenderness to percussion (i.e. with the butt of a dental mirror) can be present, I’ve found. Spontaneous pain is typically absent (although exceptions do exhist). In such cases, root canal therapy is not indicated.

   Irreversible pulpitis is characterized by moderate to severe pain when exposed to heat/cold that lingers long after the stimulus is removed, and sometimes spontaneous pain. Sometimes inflammation of the periodontal ligament at the tip of the root is present, and thus tenderness to pressure exists. Tenderness to percussion is almost always present. Irreversible pulpitis is an indication for root canal therapy.

   Your doctor will (or at least should) properly test the teeth for reversible vs. irreversible pulpitis.

   Necrotic teeth–where the pulp inside the tooth is completely dead–also need root canal therapy.

   Teeth that are severely broken down to the point where they cannot ordinarily support a restoration but exhibit no signs of pulpal problems may still need "elective" root canal therapy for the purpose of placing a post for anchorage of a restoration.

   (Believe it or not, this is an extremely abridged discussion of pulpitis!)
2. Kevin H says:

   July 5, 2010 at 7:37 am

   If the decay is in the pulp, you need a root canal. One way to determine this is for the doctor to tap the tooth lightly with the mirror handle. If that hurts, then you need a root canal. Another way is to take an x-ray.
3. Dr Stoopid says:

   July 5, 2010 at 7:37 am

   Hi,

   1. The dentist decides you need root canal when your nerve is dead or very likely to die
   2. He is generally looking at how bad condition the tooth is in either physically or by looking at an xray.

   The inside of your tooth has a hollow part filled with nerve and blood supply, if it dies this space eventually becomes infected and filled with pus and bacteria. Pressure build up, squirting the infection out the end of the tooth into the bone causes inflammation and much pain.

   What the Dentist is Seeing/ looking for:
   -very broken down teeth
   -testing if the tooth responds normally, to check if the nerve is alive.
   -as well as showing deep decay, xrays can show infection around the end of the tooth (also known as an abscess).
   -if nerve is exposed during fillings the nerve will die and so a root canal is needed.

   -Sometimes healthy teeth might need a root canal if the dentist needs to stick a "post" where the nerve goes, to strengthen a large filling which would have gone into the nerve

   I hope this helps
4. kristylee116 says:

   July 5, 2010 at 7:37 am

   When the patient is hold or cold sensitive and it lingers for a while also in the xray if the decay has gone in to the nerve of the tooth. But sometimes patients don’t have any of those symtoms anymore cuase the tooth as totally died and the nerves will look very dense or calcifed Good Luck
5. chocolahoma says:

   July 5, 2010 at 7:37 am

   I asked when they did my root canal last month.

   A root canal is necessary if a cavity penetrates the hard layer of dentin and gets into the soft pulp inside.

   The nerve itself is contained inside the soft pulp, and once a cavity opens that area up, the nerve gets exposed to the bacteria and such. The nerve is very sensitive, prone to infection, and has no room to become inflamed. (It almost impossible for antibiotics to kill the infection, especially since evey meal is a new dose of bacteria.) Almost immediately after the cavity opens into the pulp, the nerve begins to die.

   The only way to stop the decay and infection is to go inside the tooth, drill out the infected pulp and nerve, fill the hole, and then later come back and reinforce the whole thing with a percelain crown.
6. HeatherS says:

   July 5, 2010 at 7:37 am

   The need for root canal therapy is based on several symptoms that the patients presents to us. One being the tooth itself, amount of decay, particular pain, condition of the nerve or an abscess on the x ray itself. An x ray is always the quickest way to determine the status of a dying tooth by looking at a thinning pulp chamber, or in a progressed apical abscess with bone loss. This is the easiest way to show a patient an abscess that he/she can see. Usually the symptoms are swelling, heat, sensitivity to hot/cold, fistula present and draining, throbbing pain that keeps a patient up at night. The later two being the most prominent. There is no guarantee that these symptoms will be present, some teeth die with no symptoms being present and it just shows up on an x ray. That’s not always the case though. There are also ways to test a tooth’s vitality that can determine if it’s dying. Hope I’ve been of some help in answering your question.