With a few exceptions, teeth don’t heal by themselves. Every cartoon with an elderly character will show them taking out their false teeth. For many Americans, teeth simply don’t stand the test of time. They contain one of the few tissues in the body that is finite. Most people have heard of enamel from toothpaste ads, but that tissue is only 1 of the 4 that comprise a tooth. Enamel, dentin, cementum, and pulp are the four major tissues that round out a mouth full of pearly whites. Most of the previous blog entries talk about a specific dental disorder or problem and offer remedies to it. This one will be a bit of primer, a basic introduction to what teeth are, and what can go wrong for each part.
Dental pulp is soft tissue in the center of the tooth; it contains the nerve, blood and lymphatic vessels, and connective tissue. The pulp forms the main bulk, or core, of each tooth and extends almost the entire length of the tooth. It is covered by enamel on the crown portion and by cementum on the roots. The pulp consists of cells, tiny blood vessels, and a nerve and occupies a cavity located in the center of the tooth. If the pulp becomes infected, it is removed by root canal.
Cementum is the thin surface layer of bone like material covering the tooth’s root. It is yellowish and softer than either dentin orenamel. The fibers of the periodontal membrane, which holds the tooth in lace, are embedded in cementum. Deposition of cementum continues throughout life, especially in response to stresses. When the tooth’s crown is gradually worn down, new cementum is deposited on the roots so that the tooth can slowly rise to maintain a good bite.
Dentin is the yellowish tissue that makes up the bulk of all teeth. It is harder than bone but softer than enamel and consists mainly of apatite crystals of calcium and phosphate. Sensitivity to pain, pressure, and temperature is transmitted via the tubes to and from the nerve in the pulp. Secondary dentine, is a less well-organized form of tubular dentine, is produced throughout life as a patching material where cavities have begun, where the overlying enamel has been worn away, and within the pulp chamber as part of the aging process.
Enamel is the hardest tissue in the body. It covers part of or the entire crown of the tooth. Enamel is not living and contains no nerves. The thickness and density of enamel vary over the surface of the tooth; it is hardest at the biting edges, or cusps. Normal enamel may vary in color from yellow to gray. The surface enamel is harder and contains more fluoride than the underlying enamel. It is very resistant to tooth decay. Enamel is also finite. Worn enamel is a symptom of most dental problems: erosion, attrition, abrasion, and the first part of the tooth to decay from cavities. A loss of enamel over time can lead to transparent and fragile teeth. Sensitive teeth can be relieved with desensitizing toothpastes, which often contain ingredients such as potassium nitrate, potassium chloride or potassium citrate seem to make the tooth less receptive to pain. In the case of severely worn enamel, veneers are often the only option.
This concludes the reading for dental anatomy 101. I hope that it provides a greater understanding to the past and future blog entries. And if you didn’t much care for the anatomy of your chompers, there is good news. With good dental hygiene, the dentist won’t have to bother you with any of these terms and explanations; you can just take a free toothbrush and be on your way.