Immediately implantation and immediate prosthesis could preserve the alveolar contour and gingival shape. The visiting time is quiet long. Pre-made prosthesis is a way to shorten the visiting time. But the implant has to be placed precisely. Novel digital workflow integrating dynamic navigation or static surgical guide to process one-visit single -implant immediate loading is possible. The study is to compare the x-guide dynamic navigation system or static guide system which one could assist the surgery more accuracy and place the prosthesis more smoothly.

Inclusion Criteria:

• 20 to 80 years old
• Miss two functional opposing teeth in one quadrant or the same jaw
• The situation of oral tissue satisfies the condition of implant immediate loading.

Exclusion Criteria:

• catastrophic illness,
• diabetes,
• cardiovascular diseases,
• osteoporosis,
• head and neck cancer,
• disabled
• pregnant.

Any patient older than 18 years old, including both sexes. Every patient has 2 missing teeth in a jaw and one on each side. All the edentulous ridges suit the immediate loading criteria