To investigate the clinical efficacy of OsseoSpeed™ TX implants in a Chinese population by evaluation of marginal bone level alteration, implant stability and implant survival in the posterior mandible up to 3 years after loading. Hypothesis: Early loading of the posterior mandible is a safe and predictable procedure.

Inclusion criteria:

1. Provision of informed consent
2. Aged 20-75 years at enrolment
3. History of edentulism in the posterior mandible, Kennedy classes I or II, of at least four months. Last natural tooth in function is canine or first bicuspid.
4. Neighboring tooth to the planned bridge must have natural root.
5. Presence of natural teeth, partial prosthesis and/or implants in the opposite jaw in contact with the planned bridge.
6. Deemed by the investigator to have adequate bone height and a bone width of minimum 5.5 mm.
7. Deemed by the investigator as likely to present an initially stable implant situation

Exclusion criteria:

1. Unlikely to be able to comply with study procedures, as judged by the investigator
2. Earlier graft procedures in the study area
3. Current need for pre-surgical bone or soft tissue augmentation in the planned implant area.
4. Uncontrolled pathologic processes in the oral cavity
5. Known or suspected current malignancy
6. History of radiation therapy in the head and neck region
7. History of chemotherapy within 5 years prior to surgery
8. Systemic or local disease or condition that could compromise post-operative healing and/or osseointegration
9. Uncontrolled diabetes mellitus
10. Corticosteroids or any other medication that could influence post-operative healing and/or osseointegration
11. Smoking more than 10 cigarettes/day
12. Present alcohol and/or drug abuse
13. Involvement in the planning and conduct of the study (applies to both Astra Tech staff and staff at the study site)
14. Previous enrolment in the present study.
15. Simultaneous participation in another clinical study or participation in a clinical study during the last 6 months.
16. Subjects that are unable to give informed consent

3 years