The life expectancy of dental inlays is about 5-7 years. The inlay material is not like our porcelain crown is the whole package of the tooth, inlay material and the tooth is relying on the role of the cement to maintain the retention, the use of years shorter than porcelain crowns, but the biggest advantage of inlays is less damage to the tooth, to a large extent and can play a role in protecting the tooth into stress, especially for the teeth after root canal treatment, do a high inlay cover on the surface of the tooth, can The tensile stress can be changed to a downward stress to prevent the tooth from fracturing. The biggest problem of inlays is the retention and the secondary caries of the tooth. It is recommended that patients should brush their teeth well and avoid eating things that are too sticky or too hard, which may damage the inlays in advance.