The root of the tooth root feels empty may be caries, apical periodontitis, endodontitis and other causes. 1. Caries: If the teeth are not cleaned well, it will easily lead to bacteria, food for a long time on the surface of the teeth, causing dental tissue caries, often appearing inside the teeth of a large area of caries, while the outer enamel is not destroyed, resulting in the root of the root feels empty. 2. Periapical inflammation: when inflammation attacks the periapical tissues, causing the occurrence of periapical inflammation, inflammation when the gums are swollen obviously, the root of the root of the tooth feels empty phenomenon. 3. Pulpitis: Pulpitis often develops from dental caries, leading to inflammation of the nerves inside the teeth, causing bacterial invasion and infection of the dental pulp, the root of the tooth root feels empty phenomenon, and is accompanied by pain, redness and swelling and other symptoms. It is recommended that the patient should go to the hospital stomatology department in time, after clarifying the cause of the disease, follow the doctor’s instructions for treatment.