If children wearing gap retainers want to prevent tooth decay, they need to do a good job of oral hygiene before bedtime and after meals, supplement adequate nutrition and do a good job of regular review. 1. Clean oral hygiene before going to bed and after meals: children wearing gap retainers to prevent tooth decay need to do a good job of oral hygiene, it is recommended that children before going to bed, after meals, flossing, toothbrush, etc. to do a good job of oral cavity, especially teeth, teeth gap cleaning. Even if you can’t brush your teeth, it’s best to carry mouthwash with you to keep your mouth as clean and hygienic as possible. 2. Adequate nutrition: Children wearing gap retainers to prevent tooth decay need to supplement adequate nutrition, especially adequate calcium, which can be treated by drinking milk in moderation, sunbathing or supplementing vitamin D, etc., to prevent the enamel bone density from becoming low, which leads to a lower ability to prevent tooth decay. 3. Regular review: Children wearing gap retainers to prevent tooth decay need regular review to prevent tooth damage caused by deformity of the retainer, and timely detection of problems to ensure dental health. Parents are advised to take their children to the doctor in time to improve the relevant examination and standardize the treatment after they find that children wearing gap retainers have cavities.