Periodontal disease is a common and frequent disease of the oral cavity and is the most widespread chronic infectious disease in the population. It jeopardizes periodontal health all the time. At present, 80-97% of adults in China suffer from different degrees of periodontal disease. It is the first cause of tooth loss in adults. So what is periodontal disease? What is the cause of the disease? How to prevent and control it? Periodontal disease is a chronic inflammation that invades the gums and periodontal tissues, and is a destructive disease characterized by the formation of periodontal pockets and inflammation of the pocket walls, alveolar bone resorption and gradual loosening of the teeth, leading to tooth loss. The disease is mostly caused by plaque, tartar, food impaction, poor restorations, bite wounds, etc. Gums become inflamed and swollen, while plaque buildup is aggravated and extends from the upper gingiva to the lower gingiva. Due to the characteristics of the micro-ecological environment under the gums, a large number of virulent periodontal pathogenic bacteria thrive in the plaque under the gums, aggravating the inflammation of the gums and expanding, leading to the formation of periodontal pockets and alveolar bone resorption, resulting in periodontitis. The main causative factor of periodontal disease is plaque. Bacteria in plaque is the initiating factor of periodontal disease, so removing plaque and preventing or reducing plaque re-accumulation is the main measure for treating periodontal disease and preventing recurrence. At the same time, it is also an important method to prevent and control dental caries. The author believes that periodontal disease should be emphasized on prevention and early treatment. The most basic disease of periodontal disease should be plaque, in which bacteria grow, reproduce, metabolize, and produce toxins and metabolites to directly stimulate the gums, forming gingivitis, which is the early stage of periodontal disease. Therefore, the timely removal of dental bacterial class is the most important task in the prevention of periodontal disease. 1, pay attention to oral hygiene, using the correct method of brushing: improved Bass brushing method is worth clinical recommendations for more effective removal of plaque brushing method. (1) Use regular health care toothbrush. (2) Brush all sides of the teeth. (3) Brush vertically. Brushing along the gap between the teeth can play a role in massaging the gums, accelerating local blood circulation to stop and eliminate bacterial contamination. (4) Brush your teeth in the morning and evening, and rinse your mouth after meals. (5) In the process of brushing, be sure to brush all sides of the teeth, especially the inconvenient areas. You can use dental floss and interdental brush and toothpick to clean the tartar and plaque that is not easy to remove between teeth. 2, such as dentures and other restorations, should pay attention to keep the denture clean, early removal of bad restorations, timely treatment of gingival margin inflammation can prevent most of the periodontal disease. 3, functional stimulation of periodontal tissue health also has a very important role. Normal chewing has both functional stimulation. 4, pay attention to dietary regulation and adequate nutrition. 5.Adopt a healthy lifestyle. Regular oral examination, regular X-ray examination, go to the hospital to clean the teeth, remove tartar, tartar, local medicine, morning and evening light salt water rinsing. Carry out treatment for early periodontal damage and eliminate periodontal pockets. Treatment of other oral lesions related to periodontal disease, medium or even advanced periodontal disease, such as loose teeth can be fixed with orthopedic restorations, can still be considered for retention.4 Restoration of lost alveolar ridge and lost teeth to improve aesthetics and function.