Half of the tooth is broken and the inside is empty, it is often considered to be caused by large area of caries, the hard tissue of the tooth has no regenerative function, once it is destroyed, it cannot be repaired by itself, it must be filled by artificial methods and suitable materials to restore the form and function. If the tooth is half empty, you should go to the hospital for oral examination, check the vitality of the pulp, check whether the nerve is necrotic, and check the root of the tooth by oral X-ray, and then carry out the treatment of material to repair the defective part. If the nerve of the tooth is healthy, the cavity can be repaired after cleaning out the decayed material in the cavity, usually using resin filling to fill the cavity caused by caries, or polishing the decayed tooth to make full crown or inlay restoration. If the tooth decay is serious enough to cause necrosis to the nerve of the tooth, root canal treatment is needed and then the tooth is repaired. For patients with extensive caries leading to root decay, the roots of the teeth can be extracted and local piling can be done after root canal treatment, and porcelain restoration or direct dental implant can be done. Most of the tooth decay is caused by not paying attention to oral hygiene in general, so you need to pay attention to brush your teeth regularly, maintain good oral hygiene habits and actively protect your teeth.