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

An Open, Prospective, Randomized, Multi-center Study Comparing OsseoSpeed™ Implant 6 mm With OsseoSpeed™ Implant 11 mm in the Posterior Maxilla and Mandible. A 5-year Follow-up Study.

The purpose of this study is to see if OsseoSpeed™ implant 6 mm long is effective for rehabilitation of edentulism and if so, how it compares with OsseoSpeed™ implant 11 mm long. The primary hypothesis is that the alteration in bone level is equal in patients randomized to 6 mm as to patients randomized to 11 mm implants.

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