Diagnosis of Tooth Decay

If you start to experience symptoms of tooth sensitivity or tooth pain when chewing, go to your dentist for examination without waiting for your regular six month exam. These may be symptoms of tooth decay. A toothache that goes away after a while should not be ignored. The next time it may be a constant and much intense pain and your tooth may not be viable any more.

Dentists identify tooth decay and its progress by physical examination and x-rays. Dentists visually examine teeth for ‘white spots’ or visible cavities and use dental mirror and a special instrument, called ‘explorer’ to look for cavities also in the spaces between teeth.

When the teeth are probed with a dental explorer, the dentist may find a pit or hole, or find an area of the tooth that may be softer than expected. By probing a found cavity with the ‘explorer’ the dentist has a first idea about the extent of the cavity.

If a cavity is detected, the dentist will usually take x-rays to find exactly how deep the tooth decay has damaged the tooth, if it has reached close or in the pulp and help plan the best way to treat and restore the tooth. X-rays may also be used to confirm a diagnosis or to reveal hidden cavities such as under existing restorations.

If the pulp is infected, the tooth may need a root canal treatment before the dental restoration. In this case the dentist may perform the treatment or refer you to an endodontist.

The traditional method of detecting tooth decay by probing for soft spots in the teeth with a sharp metal tool is characterized by low accuracy about 60%. Furthermore some researchers have pointed out that this technique may actually promote tooth decay in certain cases. When an area without a formed cavity but with some degree of demineralization (that could possibly heal itself with remineralization) is probed, the dental tool’s sharp edge may actually create the initial hole on the enamel and also infect it by spreading plaque bacteria.

Other challenges in the detection of tooth decay are the increased accuracy in the detection of the more subtle manifestations of decay, including root cavities, cavities under existing fillings, and areas of mild demineralization.

A number of new techniques have been developed in the recent years to help in the diagnosis of tooth decay and improve the accuracy rate (using transillumination by fiberoptic lights, electrical conductivity or laser reflectivity):

• Fiber Optic Transillumination - A fiber optic-focused LED is directed through the examined tooth. Areas of decay appear darker because tooth decay scatters and absorbs more light than healthy tissue.
• LED Fluorescence - A LED light is aimed at the tooth usually in combination with an intraoral camera to capture and store the image. The device measures the reflection and refraction of the values and compares them with the expected values of healthy or decalcified enamel.
• Laser Fluorescence - A specific frequency of laser light is directed at the tooth, and the amount of reflected light is measured. Healthy teeth exhibit little to no fluorescence, but carious tooth structures exhibit fluorescence proportionate to the degree of caries.

DIAGNOdent is a device using the laser reflectivity technique, claiming a 90% detection accuracy, to help dentists find even small amounts of dental decay at the earliest stages.

Symptoms of tooth decay should be not ignored. Visiting your dentist with the first sign of possible dental caries may save you the trouble and costs of restorative and endodontic treatments, and help you keep your natural teeth strong and healthy for all your life.