Dental defect is a tooth defect caused by caries, dysplasia, trauma, wear and other reasons. Treatment requires removal of diseased tissue (for pulp with lesions, pulp treatment is required first), and then repair of the defective part. Depending on the condition and the patient’s needs, there are three main treatment options available in the endodontics department: a. silver amalgam filling; b. composite resin filling; c. CAD/CAM all-ceramic inlay. A, silver amalgam filling restoration Advantages: low price, stronger and more wear-resistant than resin materials Disadvantages: 1, the color is different from the tooth; 2, the curing process takes a long time, and there is volume expansion; 3, no bonding with the tooth, the need to sacrifice part of the healthy dental tissue to obtain retention; 4, because of exposure to mercury may cause harm to the human body or the environment, but China currently allows the use. 2, composite resin restoration Advantages: 1, can retain more healthy dental tissue; 2, closer to the natural color of the tooth. Disadvantages: 1, wear resistance is slightly worse; 2, light curing process volume contraction, may lead to edge micro-leakage. Chairside CAD-CAM inlay restoration Modern computerized restorative technology makes the ideal a reality Advantages: 1, high biocompatibility; 2, good physical properties, wear resistance; 3, provides natural tooth color and shape of the restoration; 4, high accuracy, no volume expansion and contraction, good marginal fit; 5, efficient, complete the entire restoration process in one visit; 6, more than the traditional crown restoration to preserve the 6. Preserve more healthy tooth tissue than traditional crown restorations.