Albertville, AL
The human mouth naturally contains various bacteria, one of which is Streptococcus mutans. This bacterium is nourished by sugars (otherwise known chemically as saccharides), which are found not only in sugar (in the form of sucrose) but in many other foods and beverages, including fruits and fruit juices (fructose), breads and starches (glucose), and lactose (in dairy products). S. mutans metabolizes these into lactic acid, which causes a process called demineralization to occur in dental enamel (the white, hard outer shell of the teeth). Fortunately, ions found in saliva reverse this (remineralization), but if there is too much acid, demineralization outpaces remineralization. This can lead to pitting, and then to holes, in the enamel, which are called cavities.
Cavities are very bad for the health of the tooth, as these holes expose the dentin (the interior tissue of the tooth) to the acid, causing it to deteriorate. This can expose the nerve and ultimately degrade the root of the tooth (and possibly damage the jaw).
For these reasons, dentists are trained to spot and treat cavities. How do dentists detect these?
Symptoms
A dentist may suspect cavities based on the way the patient describes the state of his or her mouth.
Typical warning signs include:
- A brown or black spot that is visible and does not go away after brushing
- Sensitivity, especially to temperature or sweet food and drink
- Dental pain over and above sensitivity, especially when chewing or biting down
- Food or floss getting stuck in the same spot consistently over time
- Bleeding, swelling, or tenderness to the gums, especially in one spot
- Bad breath of a type not caused by potent-smelling foods
Visual and manual inspection
Before diagnosing a cavity, the dentist will first conduct a visual inspection. Some cavities have progressed to the point where they are visually apparent, though others may be in spots that are hard to see or are obscured by the mouth. The dentist will usually then use a probe and mirror to inspect these obscure spots. Since healthy enamel is smooth and hard, if a probe sticks into the tooth, it is a sure sign of a cavity.
Some dentists also make use of an Intraoral Camera, which has begun to gain in popularity since its invention in the late 1980s. Nowadays, this device is a little larger than a pen and is inserted into the mouth and slowly moved. It then takes images that show up on a computer screen, allowing the dentist (and often the patient) to see if cavities are present.
Dental X-rays
In addition to a visual and manual inspection, dentists will almost always take x-rays of the teeth. This can allow dentists to detect cavities between teeth, for example, which might otherwise be difficult to detect. Furthermore, if a cavity is present, the x-ray will show how deep it goes and the extent of damage to the teeth. It may also provide clues as to whether or not a wisdom tooth is present and possibly ready to erupt.
Laser Detection
While X-rays are an extremely useful diagnostic tool, they may not detect every cavity. A cavity may be present but too small to be detected by either the eye, the intraoral camera, or an x-ray. Furthermore, teeth that are not in the best alignment may overlap, which makes the x-ray difficult to read and cavities in the overlapping teeth difficult to detect. Finally, existing fillings are rendered as solid in the x-ray, which can obscure cavities behind them.
In some cases, an additional instrument is available to dentists. “Laser detection” uses a wand-like device to send certain wavelengths of light into the mouth. Undamaged tooth enamel will allow the light to pass through (which is harmless to the underlying tissue). However, decay will cause the light to reflect back, allowing the precise location, size, and depth of a cavity to be discovered.
Next steps
Using some or all these techniques, the dentist will be able to determine whether or not cavities are present. If so, the dentist will recommend treatment options to seal up the cavity and make sure it does not cause any further damage to the teeth.
Anyone who suspects they might have cavities would be well-served to schedule an appointment with a dentist, who will provide the best course of action for treatment.