I am often asked if it is safe to have a root canal done by a dentist and to keep a dead tooth in your mouth. Just hearing a dentist saying the words, ”you need a root canal”, is enough to send most patients into a fear frenzy. This article will hopefully answer some of your questions, dispel any incorrect information and make your visits for this procedure more comfortable both physically and emotionally.
Endodontics (root canal therapy) is the treatment in which the pulp (vital organ of the tooth within the internal canals of the roots) containing nerves, blood vessels and lymph vessels is damaged by decay through the hard tooth layers (enamel and dentin) into the pulp or by trauma to or fracture of the tooth. The tissue may become irritated, inflamed, infected and possibly abscessed.
Symptoms may range from sensitivity to hot, cold and chewing to severe pain and swelling. Irritation and inflammation may be reversed by more conservative treatment such as a bite adjustment or a filling.
Infection and abscess of the pulp always require endodontics to relieve the symptoms. The basic goal of Root Canal Therapy is the removal of decaying material, maintenance of dryness, cleanliness and sterility within the root canals and filling and sealing the root canals.
The procedure is usually performed in the following manner.
1.Tooth is anaesthetized.
2.For safety and in order to keep the tooth clean and sterile, a latex rubber dam with a small hole is placed into the mouth exposing only the one tooth.
3.The dentist gains access to the pulp with a hand piece (drill).
4.The exact length of the tooth is established using an x-ray, (preferably digitally taken) and/or a piece of equipment called an apex finder, which measures the value (frequency or amplitude) of electrical conductivity at the narrowest point of the root canal (apical constriction) to locate the apex (end of root).
5.Thin and flexible, files, broaches and reamers, either steel or now the mostly used, more flexible Nickel-Titanium (Ni-TI) either by hand or on a handpiece (rotary instrumentation) will remove the decayed matter, blood vessels and nerve tissue to the apex, then widen or enlarge the canal.
6.Sterile water or Hydrogen Peroxide or Sodium Hypochlorite is used to flush and clean out the debris, necrotic (dead) tissue and bacteria.
7.The canal is dried, then a cotton pellet with/without a medicament (preferably a non-toxic one) is placed in the opening disinfect or sterilize the canal the opening is closed with temporary cement between visits.
8.When the tooth is ready, the canals are permanently sealed by filling or packing with materials discussed later in this article.
This procedure takes one to three visits depending upon the number of canals, position of the tooth, and how damaged the pulp was.
The hard tooth structure of the root remains anchored in the bone. The hard tooth structure that is visible in the mouth is later restored with a filling or a post and crown dependent upon the amount of tooth that remains.
Historically, the safety of endodontics has always been debated. Some research has resulted in the focal infection theory, which states that it’s not possible to sterilize or seal all large and accessory canals. Anaerobic bacteria that remain create a toxic environment in and around the tooth.
The body’s response to the toxins and the ingredients in the root canal materials can be local or systemic, appearing as inflammation, infection, abscess, bone damage, or allergic or immune reactions.
There may be some health-compromised patients who may benefit from the removal of some endodontically treated teeth and there is a small percent of root canals that fail. However, removal of all non-vital teeth is not and should not be a dental or legal standard of treatment.
All root canal materials used have some chemical ingredients that may be harmful to some patients. In order to disinfect or attempt to sterilize the canal, medicaments such as eugenol (oil of clove) and formocresol (formaldehyde-creosote) are used. The latter is more toxic. Often none are necessary. Sterile water, hydrogen peroxide or sodium hypochlorite may be used to flush out canal debris. The former is the least toxic and frequently used , although the latter,used by most dentists is reported to have antimicrobial effects.
The most common materials used to obturate (seal and pack ) the canal are a zinc oxide/eugenol cement (seal) and gutta percha (pack). Gutta percha is the refined, milky exudate of certain trees. When mixed with substances including zinc oxide, it becomes a pliable rubber. When heated in the thermoplastic obturation technique or in contact with oils such as eugenol, eucalyptol or chloroform, it becomes a moldable plastic or liquid which is packed or injected into the canal and will fill the space left in the canal.
More recently, Bioceramic materials, which include a combination of glasses, composites and silicates, and have been considered by some to be more biocompatible and effective, have been successfully used as a sealer along with Bioceramic coated gutta percha cones.
The least toxic material, calcium hydroxide paste, which is reported to have some antimicrobial effects, is used by some dentists to further sterilize and even to obturate the canal. Biocalex is a product that combines calcium oxide, zinc oxide and an ethyl/glycol/water liquid. Proponents claim that it is the most biocompatible material and that due to its volumetric expansion will most effectively seal the canals. Difficulty in controlling the delivery and placement of the material and the lack of appearance on an x-ray discourage extensive usage of calcium hydroxide products except in deciduous in deciduous ( baby) teeth.
In some of the products, there are stronger antibiotics such as tetracycline and chemicals like formaldehyde, which may cause a more severe physiological reaction. These products should not be used. Chlorhexidine, also reported to have some antimicrobial effects, can be used either alone or in mixture with Calcium Hydroxide, and may have some toxicity. Prior to proceeding with endodontics, it is very important that you discuss the treatment with your dentist or endodontist and that you are clear about the materials that will be used.
Despite some research about the problems of allowing a non-vital tooth to remain, most dentists, including myself, choose to do the root canal procedure rather than to remove the tooth for the following reason. When you remove a tooth, a space may be left which needs to be restored using an implant or a non-removable bridge. In the second case, adjacent teeth on either side of the space may have to be included in any bridge that is constructed. Therefore, it is possible that further dental and medical problems will occur from the treatment and the the materials that have to be used.
Other than for orthodontic purposes or in situations where wisdom teeth need to be removed, there may be circumstances when a tooth is beyond repair and has to be removed. But, I believe that these situations occur in a small percent of cases and should only happen after careful diagnosis, treatment planning and consultation with your dentist.