What is a Cavity Anyway, and What Causes a Cavity?
Of course we are thinking strictly of a dental cavity which actually may be found in the oral cavity. Patients most often refer to this problem as “having a cavity,” while the professional may refer to it as caries. Caries is the technical term for decay and is nothing more than the beginning destruction of the enamel, dentin, and even the cementum of the tooth. The enamel covers the tooth, the dentin is the layer beneath the enamel, and the cementum is basically the root of the tooth. This destruction begins when the demineralization process exceeds the reminerlization process. Notice the “de” and the “re” on the front end of “mineralization.” The former destroys enamel and cementum and the latter rebuilds the tooth. A healthy mouth keeps those two in balance. A cavity-free mouth can easily be maintained with proper oral hygiene, brushing, flossing, and proper diet. We all know that sugar is converted to acid by the bacteria which make up the bacterial plaque and the acid creates the cavity.
The acid production which creates the destructive demineralization, and therefore a cavity, can only occur when sugar is introduced and the patient has not adequately removed the bacterial plaque. This simply creates an acidic environment which can slowly destroy the enamel. It is known that fluoride in the saliva inhibits demineralization and truly reduces the chances of having decay or cavities. That is why we have fluoride in the city water supplies, toothpaste, and direct application by the dental hygienist. The areas of the tooth mostly affected are in the contact areas between teeth, the gum line, and the grooves on top of the teeth.
A cavity if caused by the constant bathing of the tooth with an acidic diet, or by allowing bacterial plaque to form, then eating sugar, and the bacteria within the plaque convert the sugar to acid which eventually will create a cavity.
The cavity may be very obvious as some of the tooth may be broken down, or it could be insidious and just beginning and the patient may be unaware of the developing problem. The dentist may diagnose the cavity by visualizing the open cavity, or he may use an instrument called an explorer to find a soft area in the tooth, or lastly, early decay or recurring decay may be diagnosed with the aid of a dental x-ray. The cavity in a tooth “feels like” leather to the dentist when he uses an explorer.
The patient usually will not be aware of insidious decay or recurrent decay. He becomes aware only if sensitivity to sweets or cold occurs. If the tooth has broken down due to extensive decay, the patient then becomes well aware that a problem exists. Appearance-wise, the tooth may seem to have thin enamel and may look “dark” in color. Prior to the tooth turning dark, the enamel may appear to be chalky. The patient may begin to experience sensitivity to sweets and cold temperatures and may also feel some sharp places on the tooth with their tongue. Food may also become trapped in the open cavity. If the cavity is more advanced and even deeper, the patient may experience a toothache which may require a root canal and/or possibly a full crown as opposed to a filling. So the cost difference in this treatment alone behooves the patient to have periodic check ups and seek treatment immediately if they suspect a cavity.
The type and cost of a filling a cavity vary. If the cavity is well-advanced, a crown is required, so that alone behooves you not to wait. The simplest filling on the chewing surface of a back tooth is an amalgam. This is often called a silver filling but is controversial in that it contains mercury. There have been false claims that there are issues with the mercury but the ADA states that there is not one credible piece of evidence that there is a problem. Literally billions of amalgam fillings have been place without consequence. If any filling is considered to be deeper than normal, usually some kind of insulating, medicated base is place beneath the filling and with the newer acid-etch bonding agents, sensitivity is rare.
Other types of fillings for a cavity or tooth-colored fillings, and gold fillings, onlays, or crowns (either gold or porcelain). On occasion, a temporary medicated filling may be utilized for a short period of time.
One factor which may accelerate the possibility of getting a cavity is a dry mouth (zerostomia) which can easily be caused by a mixture of different medicines. Well-known in this group are antihistamines, and antidepressants, but best know is “meth mouth” from the abuse of methylamphetamine. Excessive use of tobacco as well as alcohol is known to create a dry mouth environment. Radiation in the throat and neck affects the salivary flow produced by salivary glands which results in a dry mouth situation which in turn, results in the formation of more cavities. Fluoridated toothpastes and rinses are a must, and moisturizing rinses are quite helpful. Any means of enhancing moisture and salivary flow lower the chances of obtaining cavities.
“Bottle Mouth” sometimes called rampant caries, bottle rot, or baby bottle decay is a condition which arises usually from allowing a baby to drink too much sugar-water or sweet juices from a bottle, all day long or to help them go to sleep at night. The sugar leads to acid production which leads to excessive decay, or cavities.
It is readily known that acid is the culprit which results in a cavity, but it is also well-known that this acid is produced by the bacteria in the mouth converting sugar to this damaging acid. We know that saliva has a cleansing affect upon the tooth. Therefore, any condition medically which reduces the flow of saliva, increases the production of cavities. We also know that fluoride reduces the breakdown (demineralization) of the tooth and therefore reduces the number of cavities. Actually, a fluoridated water supply reduces decay by 62%.
So it can easily be said, that if one desires to reduce the number of cavities, one should utilize a fluoridated water supply, a fluoridated toothpaste, brush and floss properly often, visit the dentist twice yearly, and avoid sugar. Maintaining a healthy mouth should be a routine activity. One does not inherit teeth with cavities. It is the life-style which creates them.
Life Member of American Dental Association, Emeritus Fellow of the Academy of General Dentistry, American Association of Implants Dentists