What is the primary indication for performing transillumination on a tooth?

Transillumination is a diagnostic technique that involves shining a light through the tooth to visualize its internal structure. The primary indication for using transillumination is to detect caries, or dental decay. When the light passes through a healthy tooth, it will transmit clearly, but when there are carious lesions present, especially in the early stages, these areas will appear darker or opaque due to the altered composition and density of the affected tooth structure. This method allows for the identification of cavities that may not be visible during a standard visual examination, particularly in areas where access is limited or on surfaces that are difficult to inspect.

Assessing periodontal health, checking for malocclusion, and evaluating tooth eruption patterns do not rely on the transillumination technique. Periodontal assessments typically involve clinical probing and radiographic evaluations. Malocclusion is evaluated through occlusal analysis, and eruption patterns are assessed via examination of the dentition and developmental timelines, making transillumination specifically suited for the detection of caries.