Can dental X-rays show cavities?

In general, tooth decay refers to dental caries. Dental imaging can usually detect caries, especially hidden or occult caries that are difficult to identify with the naked eye, making it an important auxiliary tool for clinical diagnosis. The specific analysis is as follows:

Dental caries is a pathological condition caused by bacterial erosion of the hard dental tissues and can be classified into three stages based on lesion depth: initial (superficial), moderate, and deep caries. Caries occurring on the proximal surfaces between teeth, deep within occlusal pits and fissures, or at the cervical region near the gum line are often obscured by tooth anatomy and thus difficult to detect visually. However, dental radiographs can reveal internal tooth structures through imaging, clearly showing changes in the density of enamel and dentin. Due to demineralization, carious areas have lower density than healthy tooth structure and appear as dark or black shadows on radiographs. Dentists can determine the presence and depth of carious lesions based on the location and size of these shadows.

For superficial enamel caries that are located close to the surface and have not yet formed obvious defects, radiographs may not always provide clear visualization. In such cases, clinical examination by a dentist—such as probing tooth surface hardness with an explorer—is necessary to make a comprehensive assessment. Nevertheless, overall, dental radiography significantly improves the detection rate of caries and helps prevent missed diagnoses of hidden lesions.

Therefore, when caries is suspected or during routine oral examinations, dentists commonly recommend dental radiographs to fully evaluate oral health and provide accurate information for developing appropriate treatment plans. Regular dental check-ups and imaging are also recommended in daily life to enable early detection and early treatment of dental caries.