What Signs and Symptoms would show if you needed a Root Canal?

Let’s look at this from two perspectives:

• The signs and symptoms you may experience or notice which suggests a root canal may be needed.

• How the dentist determines if you should have root canal treatment -what questions he will ask and why- what tests he is likely to perform to arrive at a diagnosis.

Signs you may notice:

• A sinus

A sinus is a tract or tunnel that drains infection which has built up around the apex (end) of the root through the bone and into the mouth. It may look like a mini ulcer or nodule on the gum and often gives a bad taste, as pus will be draining from it. Often, because the infection has a place to drain, there isn’t pain associated with the tooth until the tract gets blocked and then it becomes very painful with the build up of pressure. Sometimes you can insert a GP point (the material used for filling a root canal) into the sinus and it will follow the track of the infection and point at the source- when possible… this is a very good way of identifying the tooth causing the problem.

• A swollen face (an abscess) 

This indicates a collection of pus has formed and is generally a sign that a tooth has abscessed. Whilst this could be of tooth or of gum origin, in my experience a facial swelling is more likely to be the result of a necrotic pulp (a dead nerve).

• A massive cavity

If you have half your tooth missing or a huge area of decay, the nerve will no doubt have be affected to some extent. It may be that just that the tooth needs to be restored or it may be that the nerve is dead or damaged beyond repair and a root canal is needed.

Symptoms you may notice:

• Key indicators:

Pain that lasts for minutes/hours -(not seconds) after a stimulus such as cold

Pain that wakes you in the night or disturbs your sleep

Pain when you touch a single tooth.

• Other indicators:

Pain not relieved entirely by traditional painkillers

Pain when you bite down (though a problem with the bite, such as a high filling and a couple of other potential issues must also be ruled out)

Pain that occurs spontaneously with any stimulus such as hot or cold

A bad taste in your mouth (when combined with other things above- not just in isolation).

How does the Dentist Diagnose my Problem?

The dentist will ask you a number of questions to begin with at the start of the appointment. This will give them information about the problem at hand and what may be causing it. Examples of the questions the dentist may ask you are discussed in diagnosing toothache

Root canals are necessary when the nerve has been irreversibly damaged or has died. The signs and symptoms above are those we generally associate with such situations. Some of the signs are a lot more definite than others. A swollen face is a pretty obvious sign of an abscess and infected tooth and the need for an extraction or root canal treatment. So too is finding a large area of infection on an X-ray (see below) or a discharging sinus next to the root of a tooth.

The difficulty comes when the state of the nerve is more questionable. If the symptoms suggest irreversible pulpitis, whilst a sedative dressing can calm things down, the nerve in this state is likely to continue to die until root canal treatment becomes necessary. Sometimes, leaving it may make the root canal treatment more difficult in the long run, but at the same time you don’t want to dive in there unnecessarily. The dentist may tell you the filling is deep and that it may need a root canal or extraction later. In these circumstances, it is being assumed that tooth has reversible pulpitis, but if the tooth was to become painful a few months or even years later, it would suggest that it was in fact irreversible and the nerve subsequently died.

Unfortunately the symptoms seen clinically (by the dentist) when pulpitis is present, vary quite a lot, particularly in multi-rooted molar teeth and pain is a very subjective sensation, (tending to affect males more than females)!

Whilst there is always an area of uncertainty, serious pain lasting a long time and keeping you awake at night suggests the nerve is irreversibly damaged. Pain from cold and sweetness, lasting only a few seconds suggests a reversible condition if it is dealt with promptly. If left however, this may progress and when more irreversible symptoms begin appearing, then you may well be looking at a root canal not just a filling- so it is best to get checked out quickly when you first notice anything.

This is not an exact science: reversibly and irreversibly damaged nerves are related to a spectrum of symptoms, which try to aid us in providing the most appropriate treatment. The tooth is a living tissue and will respond differently in different people and the diagnosis will almost always involve some element of uncertainty.

There are other less common reasons for needing a root canal and these are discussed in why you might need a root canal.

What Special Tests does the Dentist do?

The dentist will need to perform a number of special investigations to supplement the information he has gained from asking questions and examining your mouth. These will serve to make the picture of the problem a little clearer:

• X-rays. In any root canal cases, or where a root canal problem is suspected, then a Periapical X-ray(often shortened to PA) is required. Peri means around and apical is dental speak for the apex or end of root, so the view records the whole of the root of the tooth in question and its supporting tissues (that is one that records the whole end of the tooth).

No changes around the end of the root will be seen on the X-ray in early pulpitis; the tooth radiographically will appear normal. However, teeth that have become infected and have lost their vitality (i.e. the nerve has died) can show a range of changes. The classic picture will be a dark area around the end of the root continuing to the ligament that supports the tooth. We call this ‘peri-apical’ area, or ‘peri-apical radiolucency’. It is important to note whether it is continuous with the ligament, as this suggests the source of the infection is inside the tooth.

Bacteria in the root canal produce toxins and waste products; these leak out from the end of the tooth destroying the tissue in that area. In the very early stages we may just see ‘a widening of the periodontal ligament’, which if left will progress over time to a larger dark area.

In general, the longer there has been bacteria in the root canal, the larger the area that will be seen, but this is not always the case. I have rarely seen an area bigger than the size of a fingernail, since your body is constantly trying to protect you from harm.

A chronic problem often results when a balance is established between your body’s defenses and the invading bacteria. Chronic problems as we have discussed in relation to gum disease, often are not painful, but a weakening in your immune system, over growth of bacteria or the introduction of more nasty strains that could result in this becoming an acute problem- often a very painful abscess associated with the tooth.

A peri-apical area around a tooth that has been crowned or heavily filled is quite a frequent finding on general screening X-rays resulting in the need for treatment. The radiolucency may have been there for several years and even if left, may not give problems for many years to come.

However, since the prognosis for a successful root treatment is affected by how long the bacteria has been established inside the root, it makes sense to treat the problem as early as possible. Leaving known infection in your body is never a good idea and because this has the potential to turn into an abscess. It is best dealt with pro-actively rather than waiting until the problem arises- you can’t predict the timing when it decides to play up on your eagerly awaited holiday.

• Vitality testing. Teeth that respond positively to electric pulp testing or cold tests for the most part are alive and those that do not, are dead. This is a crude and sometimes not an accurate measure of the living status of a tooth, but it can help to identify the potential offender when it is uncertain which tooth the pain is coming from. Let’s say a number of teeth all have deep large fillings and could all be responsible for the pain. If you were to apply a cold test to all the teeth and only one of them had no sensation, the others could be assumed to have living nerves and make the one that didn’t- the focus of the dentist’s attention.

• Palpation. An area of soreness on the gum underneath the tooth (adjacent to the roots) can suggest the nerve has died and some infection and pressure build-up is present around the roots. A sinus (discussed above) may also be seen in this area if the infection has found a place to drain.

• Percussion. It is quite common for a dentist to tap on your tooth or teeth to see if any of them are sore. One tooth may stand out considerably from the rest, suggesting that the tissues around the end of your roots on that tooth are inflamed and possibly indicating a peri-apical abscess.