1.Missing teeth patients who have high requirements for aesthetics. 2.Patients who do not accept grinding of healthy teeth next to the gap of missing teeth. 3.Patients with more missing teeth or missing teeth in the last side (free missing), not suitable for other fixed restorations such as porcelain teeth. 4.The retention force of full denture is insufficient, which affects normal life, and the retention force can be increased by implantation to improve the quality of life. 5. The expectation of bone resorption and collapse after missing teeth, which will soon form the aging face is unacceptable, and the bone can be kept full and healthy by the stress effect of implant roots. 6.Patients with trauma (fracture or loss) of front teeth, who need quick restoration.