Dental radiographs are an excellent means of detecting tooth decay, but it is not impossible to diagnose tooth decay without taking dental radiographs. Tooth decay, known as caries, has many other clinical manifestations and can be diagnosed by the patient or by the dentist. Tooth decay is a disease in which bacteria invade the hard tissues of the tooth, causing them to rot and disintegrate. Even in the early stages of tooth decay, there will be a change in the color and texture of the corresponding area of the tooth, and the grooves of the tooth surface may turn black, and the application of a probe will result in the phenomenon of the probe getting stuck when it is probed, which means that the tooth is decayed. At the same time, the caries may develop deeper, further developing hot and cold stimulation pain or spontaneous pain, and then the symptoms of dental pulp appear.