CHAPTER 7 Endodontics

Root Canals, Dead Teeth, Inside of Teeth

Each tooth has a dental pulp (FIG. 7.1), commonly called the “nerve” by patients. The anatomy of the pulp is well known to dentists. Individual teeth have divisions of the pulp called root canals. Each tooth has one to four root canals. When these small pieces of soft tissue die or become injured or infected, the resulting pain can be as debilitating as almost any other physical condition experienced by humans.

FIG. 7.1 A and B show decay on the crown portion of these extracted teeth. Decay (caries) of this size can be treated without root canals. C and D show decay that has progressed to the dental pulp (nerve). These teeth require root canals to be saved.

Why does a piece of diseased or dead tissue cause pain? A tooth is usually sealed externally by the outside tooth coating (enamel). Only a small opening into the supporting bone is present on the tooth end, deep within bone. When a dental pulp is diseased or dead, pulp blood flow and cellular activity increases, and there is no possibility for release of pressure from inside the tooth except into the supporting bone. The result is pain, and it is usually present when a tooth is dead or dying. However, occasionally the infection finds its way into the bone and perforates out into the soft gum tissue. The patient observes a pimplelike projection on the gums, commonly called a gum boil, and this “dead” tooth is usually not painful.

What clinical conditions are commonly observed related to dead or dying teeth?

WHAT YOU SEE OR FEEL

Conditions, Signs, or Symptoms Related to Endodontics

1. Pressure Causes Pain

(FIG. 7.2). When chewing on the suspect tooth, significant pain is experienced. Pushing on the tooth or tapping on it with a hard object creates pain. The tooth may have periods of no pain. Antibiotic therapy usually reduces or eliminates the pain for a while. Pain on pressure may be indicative of a dead or dying tooth, but it may also indicate a cracked tooth or a tooth that has had recent heavy chewing or “bruxing” on it (see Chapter 11). If your dentist finds a dead or dying tooth, you have the following alternatives:

A. Root canal (endodontic) therapy (p. 40)

B. Extraction of the tooth (p. 92)

FIG. 7.2 Pushing or tapping on tooth creates pain.

2. Heat Causes Pain

(FIG. 7.3). If hot foods cause significant pain in a specific tooth, it usually indicates a dead or dying tooth (pulp), and you have two alternatives:

A. Root canal therapy (p. 40)

B. Extraction of the tooth (p. 92)

FIG. 7.3 Heat placed on tooth to stimulate response.

3. Red, Pimplelike Projection on the Gums

(FIG. 7.4). This red, pimplelike projection on the cheek side or tongue side of the tooth near the tooth root end usually indicates that the tooth pulp (nerve) is dead, and that the infection has broken through the bone to the outside. This condition creates a fistula, or canal, from the tooth root end through the gums. Often, yellow pus can be expressed from the red projection without much pain, but the pus will return until therapy is completed. Treatment for the draining fistula may include the following:

A. Endodontic therapy alone (p. 40)

B. Root canal (endodontic) therapy and an apicoectomy (root-tip amputation and root-tip filling) (p. 41) if the defect in the bone is large

C. Hemisection (amputation of one or more roots) may be needed (p. 44) if the disease is especially persistent and involves only one root of a multi-rooted tooth

D. Extraction of the tooth (p. 92)