Cavities can be detected through various means. The most common are clinical (physical) and radiographic (x-ray) examinations. During the clinical exam, a hand held instrument is used to search of cavities along the tooth surface.
If the instrument detects a dental cavity, it may have found weak tooth enamel damaged by acid. A visual examination can also be performed to detect cavities. Teeth that are discolored, whether it is brown or black, can indicate a dental cavity.
Dental x-rays or check-ups or bitewing x-rays, are additional useful options for locating cavities between teeth or beneath the gum-line. These cavities can be almost impossible to detect visually. In some cases, a special disclosing solution is required to diagnose any suspicious areas on the tooth.