Dental enamel does not repair itself. Dental enamel is mainly secreted by enamel cells during development, when enamel formation is completed, enamel cells will degenerate to form reduced enamel epithelium, which is no longer functional. Therefore, enamel is non-renewable, when tooth decay, enamel destruction after the body can not be self-repair, only filling treatment. In addition, it is necessary to put forward is that early caries enamel will appear demineralization, at this time the caries hole has not been formed, only the degradation of phosphate and other components of the enamel, enamel structure is still there, so it can be through the salivary ions and other components of remineralization. The key to caries prevention is to maintain oral hygiene, it is recommended that morning and evening brushing, rinsing after meals, less high sugar and sticky food, and regular oral examination early detection and early treatment.