Inlay fillings generally can be maintained for 10 to 20 years, but the specific maintenance time needs to be based on personal hygiene care, inlay material and the location of the defect and other factors to determine. 1. Personal hygiene care: inlay fillings due to the edge of the cavity line is long, late hygiene cleaning is not in place can easily lead to secondary caries and shorten the service life of inlays, so personal good oral hygiene care can extend the service life of inlays, general oral hygiene is good, inlay fillings can be maintained for more than 10 years. 2. The material of inlays: clinically commonly used inlays are all-ceramic, alloy, resin and so on. All-ceramic inlays have stable performance, good biocompatibility, and maintain a relatively longer period of time after filling; alloy inlays have good ductility and mechanical properties, and are suitable for the occlusal surface of large teeth, and their service life is relatively shorter than that of all-ceramic inlays; resin inlays have a low hardness and wear resistance, and their maintenance time is generally between 3 and 5 years. 3. The location of the defect: generally adjacent to the maxillofacial defect relative to the maxillofacial or buccolingual position of the retention force is more good, so adjacent to the maxillofacial inlays to maintain the time than the maxillofacial cavity inlays longer. Therefore, the inlay filling can maintain the time is not fixed, will be affected by a variety of factors, it is recommended to pay more attention to oral hygiene and cleanliness after the inlay repair.