Implants are used to replace missing teeth, but not all patients are good candidates. It takes a trained dentist, periodontist or oral surgeon to determine if implants are suitable for a patient. First, X-rays are used to determine if the missing tooth area has enough remaining bone to hold an implant. If bone is inadequate, augmentation surgery can sometimes generate enough bone to place implants. In addition to bone quantity, the quality of bone is also important. Dense, hard bone is better than soft, porous bone. Bone quantity and quality vary between patients, and between areas of the jaws.

Age of the patient is not a major factor as long as the person is in good health. Diseases such as uncontrolled diabetes would compromise implants. Although smoking reduces the success rate of implants, they are often still successful in smokers. Periodontitis, or gum disease, around natural teeth could affect implants. Periodontitis of the teeth should be treated to avoid loss of teeth and implants.