Once a cavity forms, there is definitely a cavity hole. It might appear that there is no hole on the surface, but the texture has already softened, forming a cavity hole; it's just that it has not been discovered by oneself. It can be seen by a doctor using an examination and can also be detected by taking dental X-rays. At this point, one should follow the treatment principles for cavities, which involve removing the decayed and necrotic material inside the cavity and then filling it with filling material. If it is an interproximal cavity, the decay inside can be removed via an X-ray and then filled. Some occlusal pit and fissure caries, which are relatively shallow, can be treated with topical fluoride medication. For cavities, it is important to detect and treat them early. Regular oral hygiene should be maintained, with brushing in the morning and evening, and rinsing after meals. If a cavity is not treated in time, it will become deeper and ultimately turn into a residual root, which will need to be extracted.