A Study Evaluating OsseoSpeed TX Using Different Drilling Protocols With Immediate Loading

• Marginal Bone Level [ Time Frame: 3 months after baseline ] [ Designated as safety issue: No ]
  Marginal Bone Level alterations will be determined from radiographs and expressed as the difference from a reference point on the implant to the most coronal bone-to-implant contact on the mesial and distal aspect of the implant.
• Implant survival [ Time Frame: 12 months after baseline ] [ Designated as safety issue: No ]
  Implant survival rate will be evaluated by both clinically and radiographically counting the number of remaining implants from implant placement to one year after loading.

The study objective is to establish that there is no statistical difference in marginal bone level change comparing a Standard drilling protocol with a Soft bone drilling protocol when using OsseoSpeed TX and immediate loading.

• Experimental: Soft bone drilling protocol
  A soft bone drilling protocol will be used in bone quality 3 and 4
  Intervention: Device: OsseoSpeed TX
• Active Comparator: Standard drilling protocol
  A standard drilling protocol will be used in bone quality 1 and 2
  Intervention: Device: OsseoSpeed TX

Inclusion Criteria:

1. Provision of informed consent
2. Female/male aged 18 years and over
3. History of edentulism in the study area of at least 3 months
4. At least 4 months healing after last grafting procedure in the study area
5. In need for implant treatment replacing one to four missing single tooth in positions 14-17, 24-27, 34-37 and 44-47
6. The study implant position must be surrounded by natural tooth roots, unless the implant will constitute the most distal dentition.
7. Deemed by the investigator to be suitable for one stage surgery
8. Deemed by the investigator to be suitable for immediate loading
9. Deemed by the investigator as likely to present an initially stable implant situation.
10. Deemed by the investigator to have a "functional" opposing dentition at the time of loading the implants.

Exclusion Criteria

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