Study Evaluating ASTRA TECH Implant System, OsseoSpeed™ Implants in the Upper Jaw in Women With Osteoporosis

Inclusion Criteria: * Provision of informed consent * Postmenopausal women aged 60 years and over * In need of 2-8 implants in maxilla * A history of edentulism in the area of implant treatment of at least 6 months. * A Bone Mineral Density (BMD) value suitable either for group A or group B: * Group A (Osteoporosis/osteopenia): BMD at least 2 standard deviations (SD) below mean peak bone density of young adults for the spine and total hip (T-score = -2 SD or less). Absolute values (g/cm2) will be used. * Group B (Control): BMD not more than 1 standard deviation below mean peak bone density of young adults for the spine and total hip (T-score = -1 SD or more). Absolute values (g/cm2) will be used. Exclusion Criteria: * Unlikely to be able to comply with study procedures, as judged by the investigator. * Untreated, uncontrolled caries and/or periodontal disease * Known or suspected current malignancy * History of chemotherapy within 5 years prior to surgery * History of radiation in the head and neck region * History of other metabolic bone diseases, e.g. Paget's disease, hyperparathyroidism, fibrous dysplasia or osteomalacia * A medical history that makes implant insertion unfavourable * Need for systemic corticosteroids * Current or previous use of intravenous bisphosphonates (esp. zoledronic acid) * Current or previous use of oral bisphosphonates * History of bone grafting and/or sinus lift in the planned implant area * Current need for bone grafting and/or sinus lift in the planned implant area * Present alcohol and/or drug abuse * Involvement in the planning and conduct of the study (applies to both Astra Tech AB staff or staff at the study site) * Previous enrolment in the present study. * Participation in a clinical study during the last 6 months.