Tooth Decay - Treatment of tooth decay

The portion of a tooth invaded by decay is called a cavity; it may be compared to an ulcer that develops because of disease in soft tissues. In treating the decay process, the dentist tries to prevent further destruction of the tooth tissue. The dentist also tries to restore as much as possible the original shape and function of the diseased tooth. The procedure used depends on many factors, including the surfaces affected (enamel, dentin, etc.) and the tooth face and angle involved, as well as whether the cavity is on a smooth area or in a pit or fissure of the tooth surface.

The decayed portions of the tooth are removed with various kinds of carbide burrs and other drill tips, as well as with hand instruments. The dentist may also use a caries removal system that reduces or eliminates drilling. In this system two solutions are combined in one liquid and squirted in a pulsating stream onto the decayed area. The stream does not harm gums or healthy teeth; rather, it softens the caries so that it can easily be scraped away. Used, generally, in conjunction with rotary or hand instruments, the “squirt” system may make anesthesia unnecessary.

In other cases an anesthetic may be injected for the comfort of the patient. The dentist usually asks whether the patient prefers to have an anesthetic before work commences. In the cleaning process, an effort is made to remove all traces of diseased enamel or dentin, but no more of the tooth material than is necessary.

The cleaned cavity is generally filled in a layering procedure. The layers of liners and bases used before insertion of the filling are determined by the depth of the cavity and other factors. If pulp is exposed, special materials may be applied to help the pulp recover from the irritation of the procedure and to form a firm base for the amalgam, inlay, plastic resin, or other restorative substance that becomes the filling.

Tooth Extraction

When it becomes necessary to remove a diseased, damaged, or mal-positioned tooth, the procedure is handled as a form of minor surgery, usually with administration of a local anesthetic to the nerves supplying the tooth area. However, there is no standard routine for extraction of a tooth, because of the numerous individual variations associated with each case. The dentist usually has a medical history of the patient available, showing such information as allergies to drugs, and medications used by the patient that might react with those employed in oral surgery. Because the mouth contains many millions of bacteria, all possible precautions are taken to prevent entry of the germs into the tooth socket.

The condition of the patient is checked during and immediately after tooth extraction, in the event that some complication develops. The patient is provided with analgesic (painkilling) and other needed medications, along with instructions regarding control of any postoperative pain or bleeding. The dentist also may offer special diet information with suggested meals for the recovery period, which usually is quite brief.

Dry Socket

Severe pain may develop several days after a tooth has been extracted if a blood clot that forms in the socket becomes dislodged. The condition, commonly called dry socket , can involve infection of the alveolar bone that normally surrounds the roots of the tooth; loss of the clot can expose the bone tissue to the environment and organisms that produce osteitis , or inflammation of the bone tissue. Dry socket may be treated by irrigating the socket with warm salt water and packing it with strips of medicated gauze. The patient also is given analgesics, sedatives, and other medications as needed to control the pain and infection.

General anesthetics are sometimes necessary for complicated oral surgery. In such cases, there are available dental offices or clinics that are as well equipped and staffed as hospital operating rooms.

Endodontic Therapy

Tooth extraction because of caries is less common today than in previous years, although an estimated 25 million Americans have had all of their teeth removed. Modern preventive dentistry techniques of endodontics now make it possible to save many teeth that would have been extracted in past decades after the spread of decay into the pulp canal. The procedures include root canal therapy , pulp capping , and pulpotomy .

Root Canal Therapy

Once the tooth has fully developed in the jaw, the nerve is not needed, so if the pulp is infected, the nerve as well as the pulp can be removed. Only minor effects are noticeable in the tooth structure after the pulp is removed, and the dentist compensates for these in filling the tooth after root canal therapy.

Briefly, the procedure of root canal work begins by examination and testing of the pulp viability. The pulp may be tested by heat, cold, or an electrical device called a vitalometer , which measures the degree of sensation the patient feels in a tooth. If the pulp is dead, the patient will feel no sensation, even at the highest output of current.

After the degree of vitality in the pulp has been determined, a local anesthetic is injected and the dentist begins removing the pulp, using rotary drills and hand instruments. By means of X-ray pictures, the dentist measures the length of the root, which may be about one and a half times the length of the crown. Stops or other markers are placed on the root excavation tools to show the dentist when the instrument has reached the end of the root. The canal is then sterilized and filled with gutta-percha—a tough plastic substance—silver, or a combination of the two, and a cap is added.

Pulp Capping

Pulp capping consists of building a protective cover, or cap, over the exposed pulp with layers of calcium hydroxide paste, which is covered by zinc oxide and topped with a firm cement.

Pulpotomy

A pulpotomy procedure involves removal of the pulp in the pulp chamber within the crown of the tooth, while leaving the root canal pulp in place. The amputated pulp ends are treated and a pulp-capping procedure is used to restore the crown of the tooth.