Dr Kristi Tähepõld, dentist at Kreutzwaldi Hambakliinik
Why is it sometimes necessary to treat the root canal?
The way a tooth is built, is that it is surrounded by enamel, a very strong material protecting the tooth from various external effects. However, under certain conditions, the microbes can break through the enamel and cause a cavity (caries.)
If left untreated, the caries will progress through the teeth (through the dentine) and reach the root, also called pulp. Pulp is made of living tissue and it has nerves and blood vessels that nourish the tooth.
In case of a deep caries, when the microbes get very close to the nerves, the pulp gets damaged permanently and it may cause tooth ache or the loss of vitality of the tooth. In both cases it is necessary to get endodontic (root canal) treatment.
What is root canal treatment?
It is a procedure during which the inside of tooth, including the pulp, is cleaned. The dead or dying nerve is removed and the microbes destroyed
How is it done?
Firstly, the caries will be removed and the walls of the tooth will be restored with filling. It is necessary in order to support the tooth during treatment (dead teeth do not have blood supply, are fragile and easily breakable) and it also allows the use of cofferdam- a special rubber dam that serves to isolate the tooth. It keeps the tooth free of saliva, but also keeps the corrosive substances used to clean the root canals from getting into the patient’s mouth.
How are the root canals cleaned?
Root canal treatment consists of two parts: mechanical treatment and chemical cleaning.
Very fine needle-shaped drills and files are used for the mechanical treatment. Nowadays, most of the work is done with rotating needles or drills made of nickel-titanium which makes them extremely flexible. It allows the treatment of curved root canals.
For a successful treatment, it is necessary to clean the whole pulp from crown to the tip.
During the mechanical treatment, chemical substances are used to help remove the dead nerve and destroy the microbes.
How long will it take?
Usually several visits are necessary for a successful root canal treatment. During the first visit, the canals will be cleaned and a sterilizing medication will be placed inside them (usually calcium hydroxide.) During the next visit, the canals will be filled. Usually gutta-percha is used; it is a special soft material which, when heated, tightly fills the canals and keeps the microbes from getting inside again. It can also be removed, should it be necessary.
In some cases, root canal treatment can be done in one visit.
After the root canal treatment, the tooth needs to be restored, often by using posts, fillings or crowns.
Can the tooth still be treated if an instrument has broken inside it?
Nowadays, several technological advancements help us preform the treatment:
- Digital X-rays are fast and the radiation dosage is very small. It helps to evaluate the size and shape of the root and canals and also to give a more accurate prognosis.
- Magnifiers and microscopes help improve visibility in the narrow, dark and curved root canals. In case of straight canals, we can even see the tip of the root canal. Microscopes also help in more difficult cases, for example, if we need to locate and remove needles that have broken inside the root canal.
- Ultrasound apparatus enables us to remove instruments that have broken inside the root canal, old fillings (cement) or posts cemented into the root canal.
Is it possible to save an inflamed tooth that already has a post in the root canal?
In some cases, when the root canal has been closed or the standard cleaning has not removed the inflammation, it is possible for a surgeon to clean the source of the inflammation under the root of the tooth through the jawbone. This procedure is called apicoectomy or root tip surgery. It can also be used if the problematic tooth is located under a bridge, has a post inside and it is impossible or unreasonable to remove them.