Say “root canal” and most people shudder with imagined pain and apprehension. But ask the millions of Americans who have had root canal treatments in recent years and you will hear a far happier tale. In a 1985 survey of 1,019 adults, 80 percent said the procedure was painless and far less complicated and uncomfortable than they had expected. Of the 20 percent who said root canal therapy was painful, most have confused it with the pre-existing pain of the infected tooth.
Improvements in anesthesia and technique, as well as better training of dentists, have resulted in speedier, less painful and more successful treatments when the soft tissue inside the teeth becomes infected.
As a result, there has been a sharp increase in the number of root canal procedures done annually, from 3.1 million in 1950, to an estimated 23.5 million in 1987. This, in turn, has meant that far more teeth are being saved, with a commensurate reduction in extractions and the need for costly bridgework or dentures.
At the same time, the field of root canal therapy has been struggling for a new public image that better matches reality. For starters, it has taken on a new name: endodontics, from “endo,” meaning within, and “dontics” referring to teeth. The dental specialists devoted to saving teeth through root canal therapy call themselves endodontists.
The public comes by its negative image of root canal therapy honestly. Archaeological evidence indicates that it was practiced as early as the second or third century B.C., albeit in rudimentary form. Despite considerable progress in the intervening centuries, the less-than-perfect methods of anesthesia and treatment practiced in centuries past sullied its reputation.
Fortunately, techniques and practitioners have changed. Those of you who still harbor strongly negative feelings about root canal therapy should know that modern endodontics can help you keep your own teeth for the rest of your life.
In the last ten to twenty years, there have been great innovations in the art and science of root canal therapy. Root canal therapy has become more automated and can be performed faster, thanks to advances in automated mechanical instrumentation of teeth and more advanced root canal filling methods. Endodontists also possess newer technologies that allow more efficient, scientific measurements to be taken of the dimensions of the root canal that must be filled. Many endodontists use microscopes to perform root canals, and the consensus is that root canals performed using microscopes or other forms of magnification are more likely to succeed than those performed without them.
“The best time to undergo root canal therapy is when there is no pain,” said Dr. Joseph Schachner, a general dentist who practices in the Bronx. “A lot of people are walking around today who need such treatment but don’t know it because it doesn’t hurt yet. It’s up to your dentist to pick up the problem before it causes pain.”
The crown, the part of your teeth that you can see, is covered by a hard layer of enamel. Beneath that lies the dentin, another hard tissue. Under the dentin and extending down into the roots is the pulp, a soft tissue that houses nerves, blood vessels and lymph vessels. The pulp’s job is to form the teeth and nourish them.
Normally, the pulp is protected from the many infectious organisms in the mouth. But infection can spread into the pulp when decay moves through the enamel and dentin, or when the hard layers or fillings crack and expose the soft tissue. An infection can also spread when a tooth is dislodged or damaged by trauma. If an infection remains untreated, it can progress through the tooth’s roots and into the supporting bone, causing a painful abscess.
Sometimes endodontic therapy is needed because a tooth’s nerve has been damaged by periodontal disease, trauma or the need to cut down a tooth to fit it with a cap. Endodontics may also be used to remove unsightly discoloration by bleaching the tooth from the inside.
The usual purpose of endodontics is to remove the infected pulp (or damaged nerve), sterilize the tooth’s roots and seal the area to protect it from future infections. Even when all of a tooth’s pulp must be removed, the tooth can remain alive indefinitely, nourished by nearby tissues.
Dr. Donald E. Arens, an associate professor of endodontics at Indiana University, likened the therapy to cleansing a wound.
“We remove the source of infection and create an environment in which the tissue can heal,” he said. In his office in Indianapolis, he said, “we save more than 98 percent of the teeth we treat.”
The treatment starts with an examination, including X-rays, to assess the extent of the trouble. Electrical impulses may be used to test the tooth for sensitivity to heat, cold and pressure and to measure the pulp chamber and root canal. Then a local anesthetic, usually lidocaine, is injected to numb the area. The tooth is then isolated using a rubber dam, and an opening is drilled through the crown of the tooth.
Ultrasonics and highly refined tiny files worked by hand are used to remove the infected pulp and thoroughly cleanse and shape the pulp chamber. Medication may further sterilize the root canals. If there is an abscess, antibiotics will be prescribed and the tooth will be left unsealed and allowed to drain until the infection is cured.
If more than one treatment is needed, a temporary filling will be placed in the pulp chamber. When all signs of infection are gone, the root canal will be lined with cement and filled and sealed with a soft, pliable material called gutta percha, which conforms to the space and prevents bacteria from entering. The patient’s general dentist then completes the restoration of the tooth, usually with a gold or porcelain crown supported on a post set into the remaining base of the tooth.
Typically, endodontic therapy involves two or three visits, followed by the final restoration. Sometimes the job can be done in one visit. Any posttreatment pain, which may result from irritation of nearby nerves, is usually relieved by overthe- counter medication and rarely lasts for more than a few days.
Cost of the therapy, often in the neighborhood of $1500 to $2000, depends on several factors, said Dr. Noah Chivian, director of endodontics at Newark Beth Israel Medical Center. These include the number of roots involved (some teeth have one, others two or more), the location and position of the tooth (some are difficult to get to), the number of treatments required and the training and skill of the practitioner.
Significant portions of this article were excerpted from New York Times article By Jane E. Brody February 4, 1988. Statistics and cost projections have been updated.