Extra Short Implants Brånemark System® RP Ø4.5x4.5 mm Implants

Inclusion Criteria: * The subject should be at least 18 years of age and have passed secession of growth * The subject should be in need of an implant-supported restoration in the posterior region of the mouth (maxilla: first premolar to third molar, mandible: first premolar to second molar, not third molar due to mobile gingiva), where at least 2 implants are needed of which at least one should be an Extra Short Implant * Obtained informed consent from the subject * The subject must be in such a physical and mental condition that a 5-year follow-up period can be carried out without foreseeable problems * The subject should have a severely resorbed posterior mandible and/ or maxilla. * Implants are only to be placed in healed sites, defined as a site with minimum 6 months of healing following tooth extraction * At least 6 mm residual bone width, between 4-7 mm residual bone height in the maxilla and between 6-9 mm residual bone height in the mandible * At implant installation the implant should be stable; final tightening torque of the implant about 25 Ncm or higher, preferably not exceeding 45 Ncm * The subject should be healthy and compliant with good oral hygiene * Favorable and stable occlusal relationship Exclusion Criteria: * The subject is not able to give her/his informed consent of participating * Health conditions, which do not permit the surgical treatment * Reason to believe that the treatment might have a negative effect on the subject's total situation (psychiatric problems), as noted in subject records or in subject history * Any disorders in the planned implant area such as previous tumours, chronic bone disease or previous irradiation * Alcohol or drug abuse as noted in subject records or in subject history. * Heavy smoking (\>10 cigarettes/day) * Intake of medication containing bisphosphonates * Uncontrolled diabetes, i.e. a subject with diagnosed diabetes that has a history of neglecting doctor's recommendations regarding treatment, food and alcohol intake * Severe bruxism or other destructive habits * Immediate insertion (i.e. placement of the implant immediately after extraction) * Bone augmentation procedures before or at implant installation is not allowed * Deviation from stated drilling protocol, utilizing osteotomes, is not allowed * Lack of opposing dentition * Single crown restorations are not to be performed in the study