Anatomical Background of Cavities
Your teeth break the food you eat into pieces that can be readily swallowed and digested. Teeth are alive. The pulp at the heart of each tooth contains blood vessels and nerves that sense heat, cold, pressure, and pain. A hard substance called dentin surrounds the pulp. On the crown (the part of the tooth above the gum), the dentin is covered by a layer of enamel. The root of the tooth lies below the gum and and is covered by a protective layer of a bone-like material called cementum. In health, the gums fit tightly around the teeth; the roots of the teeth fit into sockets in the jaw bone. A shock-absorbing material, periodontal ligament, lines the socket of each tooth and protecting the skull and jawbone from being jarred.
Enamel is the hardest material in you body; however, acids produced through bacterial action can erode enamel and lead to decay, If left unchecked, decay will progress through the dentin and into the pulp resulting in pulpal death and/or abscess formation.
When the pulp dies the tooth dies. The pulp may die after dental decay has penetrated into it, or sometimes as a result of a traumatic blow to the tooth. Occasionally, a tooth dies for no apparent reason. No symptoms signal the death of a tooth, except that a decayed tooth will no longer be painful. You may not know you have a decayed tooth until your dentist tells you. Eventually, most decayed teeth turn slightly gray. Once a dead tooth has been detected, it almost always should be treated. There is a risk, especially following decay, that bacteria from the dead pulp will seep through the end of the root and cause an abscess to form in the surrounding bone.
Dentin contains small canals that lead to the pulp. Bacteria that have progressed through the outer layer of enamel reach these canals and progress directly to the pulp. Your body responds to the invasion by sending white blood cells into the area to combat the bacteria. The blood vessels around the tooth enlarge to accommodate the extra blood and white cells. The enlarged vessels press on nerves entering the tooth and the result is a toothache. If a significant number of bacteria invade the pulp chamber, the tooth's nerve will probably die (even though the white blood cells are fighting off the infection). Once the nerve becomes non vital, the toothache will end; however, the continued presence of bacteria will usually lead to an abscess.
Symptoms
In the early stages of decay the main symptom is a mild toothache upon eating anything sweet, hot, or cold. If the decay is allowed to continue, you may notice an unpleasant taste in your mouth that comes from stagnant food and bacteria trapped inside the cavity. In the final stages of decay, the pulp becomes inflamed. If this is allowed to continue, you may suffer persistent pain after eating sweet, hot, or cold foods. You may also notice sharp or stabbing pains (in the jawbone or below the decayed tooth). It's often difficult to tell which tooth is the one that hurts.
Health Risks
Tooth decay generally doesn't present a risk to one's health as long as it is caught and treated early. However, there is a risk for people suffering from heart disease. If bacteria from an infected tooth enters the bloodstream, the disease may worsen (see bacterial endocarditis).
Home Care
Keep dental decay to a minimum by taking good care of your teeth. Brush and floss regularly, reduce your sugar intake, use a fluoride toothpaste and visit your dentist regularly to have your teeth cleaned and examined. If you have young children, do not allow them to go to sleep with a bottle of juice as a pacifier. The sugary juice can bathe the teeth all night, promoting tooth decay. For more information on baby bottle decay, see our section on children.
We're out participating at educational conventions and seminars throughout the year and we'd like to use this blog as a dental resource for our community of Phoenix, AZ (and beyond). Of course, we welcome you to join the conversation. Suggest topics and ask those burning questions about dentistry that keep you up at night. Please feel free to contact me through the Morse Family Dental website. Remember, the advice provided here is intended to aid you in understanding some of the treatment options available. It is important to note that before beginning any course of treatment you should always see your dentist.