Hello, when filling a tooth, you can know the situation around the root and the degree of internal lesions of the tooth through X-ray. Generally speaking, the tissues buried under the gum, such as the alveolar bone around the root, periodontal ligament and even the potential teeth in the alveolar bone, are invisible to the naked eye. Only through X-ray can doctors determine the surrounding environment of teeth and the condition of root canals, and take better treatment plans.