Study on ASTRA TECH Implant System, OsseoSpeed™ Implants in Patients Missing All Teeth in the Upper Jaw, Restored With Provisional Teeth Within 24 Hours

Inclusion Criteria: * Provision of informed consent * Aged 20 years and over * History of totally edentulous maxilla of at least three months * Radiographic finding indicating bone quality class 3 or 4 (Lekholm and Zarb) in the maxilla * Radiographic finding indicating bone quantity class C, D or E (Lekholm and Zarb) in the maxilla * Presence of natural teeth, partial prosthesis and/or implants in the mandible, within positions 35-45 (according to the FDI digit system) * Deemed by the investigator as likely to present an initially stable implant situation suitable for immediate loading. Exclusion Criteria: * Unlikely to be able to comply with study procedures, as judged by the investigator * Uncontrolled pathologic processes in the oral cavity * Known or suspected current malignancy * History of radiation in the head and neck region * History of chemotherapy within 5 years prior to surgery * Systemic or local disease or condition that would compromise post-operative healing and/or osseointegration * Uncontrolled Diabetes Mellitus * Corticosteroids or any other medication that would compromise post-operative healing and/or osseointegration * History of bone augmentation in the maxilla within 6 months prior to surgery * Known pregnancy at time of enrolment * Present alcohol and/or drug abuse * Current use of tobacco or history of tobacco use within 6 months prior to surgery * Need for interpreter