Dental implants can make it easier for people to have a third set of teeth. There are many strict examination items before dental implantation, some of which we can understand, so what is the use of X-ray and ct scanning? For those who are worried about the radiation effects caused by X-ray and CT examination, it is really necessary to know why X-ray and CT examination are needed. To judge the number, height and thickness of alveolar bone, dental implant experts introduced X-ray and CT examination, mainly to check the bone quantity, height and width of the remaining alveolar bone in the implant area, and to check the position of the bottom of the upper collar sinus and the position of the inferior and neural tubes to help determine whether the patient is suitable for implantation and to help determine the length and diameter of the implant. At the same time, check whether there are cysts, embedded teeth and sinusitis. In the surgical area and surrounding bone tissue. The quality of alveolar bone is more important, which is an extremely important condition for successful implantation. Good alveolar bone quality is the basic condition for the long-term healthy existence of implants. To ensure the healthy recovery of alveolar bone after operation, it is necessary to consider whether the local bone mass is healthy, whether there is serious alveolar bone atrophy and bone defect caused by trauma or operation. In addition to routine clinical examination, more X-rays are taken, such as dental films and curved sectional films. Through X-ray film, we can understand the anatomical structure of the implant area, such as the upper cranial sinus, mandibular canal, mental foramen, nasal cavity and so on. And we can also get a preliminary understanding of the arrangement and bone density of trabecular bone in the implant area. Planting in different areas needs to consider its specific indications. In the maxillary anterior teeth area, the three-dimensional position of the implant should be determined before implantation in order to obtain good function and satisfactory aesthetic effect after restoration. The important anatomical obstacles to the implantation of this area are the nasal floor and incisor foramen. The incisor foramen should be considered when the implant is implanted in the anterior maxilla where absorption occurs. Epithelial tissue exists in the incisor hole, and the normal osseointegration can not be obtained after the implant is implanted in the incisor hole, which affects the osseointegration effect of the whole implant. X-ray on the left and CT scan on the right. The quantitative analysis and accurate judgment of bone quality in implant area need CT examination. Computed tomography can display the three-dimensional structure of the jaw, accurately calculate the height and width of any section of the skull, and important adjacent anatomical structures. In addition, we should also know the thickness of mucosa and soft tissue in the bone transplantation area.