In addition, to wear, tear, and injury, the major threat to the health of a tooth is bacteria. Bacteria can cause tooth decay, and the human mouth is a tremendous reservoir of bacteria because the mouth is warm, dark, moist, and usually contains tiny particles of food which help nourish the organisms.
The bacteria found in the mouth are of two kinds, aerobic and anaerobic. Aerobic bacteria need oxygen to survive; anaerobic bacteria do not. Anaerobic bacteria can find their way through cracks and crevices into areas of the mouth or teeth where there is little or no oxygen and continue their cariogenic, or decay activity.
Saliva offers some protection against the decay germs, for reasons not well understood, but there are crevices and deep pockets around the teeth and gums where saliva does not penetrate. Paradoxically, saliva itself contains millions of different bacterial organisms. Dental scientists have calculated that one ounce of saliva may contain as many as 22 billion bacteria.
Even a presumably healthy mouth may contain more than ten varieties of bacteria, plus protozoa and yeast cells, The yeast cells and at least three of the different kinds of bacteria are capable of producing acids that erode the tough enamel surface of a tooth.
Bacterial Acids and Plaque
The acids produced by decay bacteria actually are waste products of the organisms’digestive processes; bacteria, like other living creatures, eventually excrete waste products after a meal. As unpleasant as the thought may be, tooth decay can be the result of feeding a colony of germs in the mouth. Bacterial growth hence the production of harmful acids is encouraged by the consumption of too many foods composed of refined sugars.
The sugars of candies, cakes, soft drinks, and the like are easier for the bacteria to eat and digest than those of fruits, vegetables, and other less thoroughly processed foods. Even a tiny bit of food remaining in the mouth after a meal may be enough to support many millions of bacteria for 24 hours or more.
An additional contributing factor to tooth decay is plaque formation. Plaque is a sticky, transparent substance that forms a film over the surface of the teeth. Plaque forms every day, which is the reason that the teeth must be brushed every day.
Plaque frequently begins with deposits of soft food debris along the gum line after a meal it consists mainly of bacteria and its products.
When mixed with mucus, molds, tissue cells from the membranes lining the mouth, and mineral salts, it takes the form of a white, cheesy substance called materia – alba.
if not removed regularly by brushing and the use of dental floss, this substance becomes a thick, sticky mass which has been compared to epoxy cement. Then it becomes a rough surfaced hard substance with the texture of stone, otherwise known as dental calculus, or tartar.
What are The Causes of Tooth Decay?
Bacterial acid is not the only way in which the tooth enamel may be damaged to permit the entry of decay bacteria. Certain high acid foods and improper dental care can erode the molecules of enamel. Temperature extremes also can produce cracks and other damage to the enamel; some dental scientists have suggested that repeated exposure to rapid temperature fluctuations of 50 ° F, as in eating alternately hot and cold foods or beverages, can cause the enamel to develop cracks.
Complications of Tooth Decay
Once decay activity breaks through the hard enamel surface, the bacteria can attack the dentin. Since the dentin is about 30 percent organic material, compared to 5 percent in the enamel layer, the decay process can advance more rapidly there.
If the tooth decay is not stopped at the dentin layer, the disease organisms can enter the pulp chamber where they will multiply quickly, producing an acute inflammation and, if unchecked, spread through the blood vessels to other parts of the body.
Osteomyelitis, an infection of the membrane covering the skeletal bones, and endocarditis an extremely dangerous heart ailment, are among diseases in other parts of the body that can begin with untreated tooth decay.
Periodontal disease, described below, is another possible complication of tooth decay.
What is the 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 such as the skin or stomach, The objective of the dentist in treating the decay process dental caries is to prevent further destruction of the tooth tissue and to restore as much as possible the original shape and function of the diseased tooth.
The procedure used depends upon 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 cavity is removed with various kinds of carbide burs and other drill tips as well as by the use of hand instruments. The dentist tries to remove all traces of diseased enamel or dentin, but no more of the tooth material than is necessary.
A local anesthetic may be injected for the comfort of the patient; the dentist usually asks the patient if he prefers to have the anesthetic before work commences.
The cleaned cavity generally is filled in a layering procedure. The layers of liners and bases used before the insertion of the filling are determined by such factors as the depth of the cavity. If the pulp is exposed, for example, 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, or other restorative substance that becomes the filling.