Study Comparing OsseoSpeed™ Implants of Two Different Lengths in the Upper and Lower Posterior Jaw

Inclusion Criteria:

- Provision of informed consent

- Aged 20-70 years at enrolment

- History of edentulism in the study area of at least four months

- Neighboring tooth/teeth to the planned bridge must have natural root(s)

- Presence of natural teeth, partial prosthesis and/or implants in the opposite jaw in
contact with the planned bridge.

- Deemed by the investigator to have a bone height of at least 11 mm and a bone width of
minimum 6 mm

- Deemed by the investigator as likely to present an initially stable implant situation

Exclusion Criteria:

- Unlikely to be able to comply with study procedures, as judged by the investigator

- Earlier graft procedures in the study area

- Uncontrolled pathologic processes in the oral cavity

- Known or suspected current malignancy

- History of radiation therapy in the head and neck region

- History of chemotherapy within 5 years prior to surgery

- Systemic or local disease or condition that could compromise post-operative healing
and/or osseointegration

- Uncontrolled diabetes mellitus

- Corticosteroids or any other medication that could influence post-operative healing
and/or osseointegration

- Smoking more than 10 cigarettes/day

- Present alcohol and/or drug abuse

- Involvement in the planning and conduct of the study (applies to both Astra Tech staff
and staff at the study site)

- Previous enrolment in the present study.

- Severe non-compliance to protocol as judged by the investigator and/or Astra Tech

- Simultaneous participation in another clinical study, or participation in a clinical
study during the last 6 months