Non-renewable organs such as teeth often chew and grind food, which is easier to wear. Moreover, food residues in the mouth are easy to breed bacteria, which further leads to accelerated tooth wear.

Dental diseases include diseases of teeth themselves, periodontal diseases around teeth and diseases of tooth arrangement. General dental diseases are divided into caries, pulp diseases and periapical diseases. Dental caries can be divided into shallow caries, moderate caries and deep caries. Pulpitis can be divided into reversible pulpitis and irreversible pulpitis, as well as acute pulpitis and chronic pulpitis. Periapical diseases are divided into acute periapical periodontitis and chronic periapical periodontitis, as well as apical granuloma and apical cyst. Periodontal disease is divided into gingivitis and periodontal disease. The diseases of dentition can be divided into crowded dentition, interdental space and jaw diseases, such as mandibular protrusion and mandibular retraction.

There are many reasons for dental diseases, such as people's diet structure, especially eating too much sweets will corrode the health of teeth. In addition, not paying attention to oral hygiene can easily lead to dental calculus and periodontal disease.