Root Treatments in Dentistry
Root treatment is neccesary when the tooth's nerve (pulp) has become inflamed.
This may be a result of: bacteria (due to deep decay or advanced periodontitis), thermal damage as a result of drilling by the dentist, or chemical irritation (due to various dental materials).
Dentine, the tooth material underlying the enamel has small channels running through it which are directly linked to the tooth’s nerve. The bigger the problem with the tooth the more damage to the dentine and the more likely there’ll be an inflammation of the nerve.
Inflammation of a tooth’s nerve can lead to inflammation of the jawbone if left untreated or if not treated properly.
Consequently we differentiate between:
- infectious causes (bacteria)
- physical/chemical damage (heat, chemicals)
In the case of infectious causes there’s an increased danger of pathogens spreading to the jawbone and thus causing an inflammation there.
In the case of physical/chemical damage the pulp tissues usually break down, what’s called necrosis. Necrotic tissues can also cause inflammation in the bone though this happens less often. Usually the body (its immune system) manages to break down and heal the necrosis. This necrotic tissue often becomes calcified, what’s called root canal sclerosis. Again, years later this could lead to root re-absorbtion – the root turns into bone. Sometimes all these processes can run concurrently in one tooth.
(Tooth X-Ray right: A crown treatment years ago which through thermal damage whilst drilling led years later to the phenomena described above – root re-absorbtion, root canal sclerosis, inflammation of the bone).
How it develops depends on whether the bacteria are already there or not and how the body copes with the inflammatory reaction.
But first a little about our immune system. It’s capable of recognising and eliminating both foreign structures and harmful ones. So-called marker cells recognise and mark foreign structures (e.g. bacteria, dead cells, cell remains, viruses and fungi). Then ‘feeding’ cells recognise these marks and remove these structures. The inflammation is removed.
For an immune reaction to happen, immune cells which are to be found in the blood are needed. In order to fight the inflammation there must be a supply of blood to the inflamed location.
After a root treatment the root canal is now a “stony hole” without blood vessels, on the walls of which cell remains resulting from the treatment can still be found. The nearest blood vessels are to be found in the jawbone so, in the absence of blood, the bacteria have the ideal conditions in which to multiply. They are so to say ‘sheltered’ from the immune system in their man-made “cave” and can feed on cell remains and multiply undisturbed.
At some stage the number of cells becomes so great that the bacteria spread out to the jawbone through a tiny opening in the root tip and this leads to an inflammation in the jawbone. The body is often now no longer able to deal with the large number of bacteria. The inflammation marches on and acute clinical symptoms (pain) develop.
However, even in the absence of bacteria there can be inflammation. If there are a lot of tissue remains after a root treatment or because of existing anatomy of the root canal and it becomes “rotten-necrotic” then the immune system may also be overcome when it comes to breaking this down. Insufficient immune cells at the location lead to the formation of an inflammatory reaction.
The likelihood of inflammation therefore depends on different factors:
- Accessibility of the immune system
- Immune status of the patient
- Type, quantity and aggressiveness of the triggering cause
- Local factors (anatomy, advantages the microorganisms may have...)
The symptoms of an inflamed tooth nerve can be very different. This is a description of the various forms and their formation.
- In 'ideal' cases you feel strong pains radiating over the face, the tooth is very sensitive to disturbance – this is acute tooth nerve inflammation (pulpitis).
- This acutely painful phase often goes on to become a dull pain which goes away after some days. The tooth doesn’t react to cold any more at the dentist’s, x-rays show changes such as root canal sclerosis and/or a widening of the periodontal gap – it’s necrosis of the dental pulp. How it will turn out is unknown at this stage. It may develop into an acute inflammation of the bone (sometimes after years) or it may ‘merely’ end as root canal sclerosis.
- Many patients don’t feel any pain at all in the acute phase and the tooth only becomes sensitive to tapping after years – this is necrosis of the dental pulp with subsequent inflammation of the bone.
- Again, others don’t feel anything or aren’t aware of quick flashes of pain. They notice a “spot” in the mouth which leaks pus – this is inflammation of the bone. The body can’t overcome the ‘heat-source’ and has isolated it with scar tissue. The invasion of bacteria is thus halted and now the body drains away the immune cells and bacteria via a fistula in the mouth.
The transition of these reactions are fleeting and often several combinations appear together. Many may take years to develop. We must also not forget that every patient feels pain differently.
What's To Be Done?
All teeth which have been drilled or filled must be checked for vitality every six months. When a cold stimulus doesn’t produce a reaction (a dentist speaks of ‘not sensitive’) this could be a clue that the dental nerve has sustained damage since a healthy nerve will pass on the cold stimulus. It’s therefore irrelevant how strongly you feel the cold as even a little means there’s ‘something’ there.
Care is required when the cold stimulus is felt for a long time, even after the cold stimulus is removed and pain follows. This could be an indication of an acute nerve inflammation.
If nothing is felt, x-rays should be done and if changes are visible here too which show a dead dental nerve then a root treatment is necessary as the nerve is dead and has become a potential threat to the body.
Every 'hot spot‘ sets off a reaction to inflammation. It puts a strain on our immune system; the body is busy ‘working’ all the time, even when you don’t feel any pain and don’t notice your ‘hot spot’. In addition when it comes to an infected spot, it could lead to the dispersal of bacteria. These ‘travelling bacteria’ settle where they can avoid the immune system, e.g. on artificial body parts (dental implants or artificial heart valves for example), body parts with poor blood circulation (diabetics’ extremities) or where there’s a good supply of food (blood clots or thromboses). In these locations these redistributed bacteria again provoke local inflammation reactions and cause harm.
Non-infectious spots (e.g. a necrotic tooth after thermal damage) can also serve as feeding stations and hideaways for bacteria. Every problem therefore needs to be treated, independently of its historical origin.
The Aim of Root Treatment is Clear
What should be achieved:
- all passages have to be cleared from root canal tissues as well as any possible pre-existing bacteria.
- In order to ensure an optimal filling of the ‘cavity’, the walls of the tooth socket must be made smooth and conical
- Chemical-medical reduction or elimination of microbial activity in the cavity worked upon.
- No transportation of new germs from the saliva
- Tight filling of the canals in order to remove ‘living space’ for any possible remaining germs. In order to spot all the canals magnification with a microscope is needed.
Talking about instruments, new developments are happening all the time. Not only good instruments are required but also their maintenance schedules must be followed rigorously.
During the treatment new bacteria are not to be allowed access to the root canal. A coffer-dam will see to it that bacteria in the saliva are kept away from the work-area.
The canals must be thoroughly cleaned with rinsing fluids which should not be allowed into the rest of the mouth, so a coffer-dam is unavoidable.
Sometimes it is actually necessary to reinforce the work-area with additional pastes – clean work is our motto! Otherwise there’s a danger that the root treatment may lead to a root-tip resection years later with consequent extraction.
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