The TREFOIL Concept 5 Year Clinical Investigation

Inclusion Criteria: * Obtained informed consent from the subject. * The subject is at least 18 years of age (passed cessation of growth) and not older than 80 years. * The subject is in such a physical and mental condition that a 5-year follow-up period can be carried out without foreseeable problems. * The subject fulfills the prerequisite that a harmonic, stable occlusal relationship can be achieved with opposing natural teeth resp. fixed or removable opposing dentition (tooth or implant based) or soft tissue born denture. * The subject is willing and able to comply with all study related procedures (such as exercising oral hygiene and attending all follow-up procedures). * The subject is compliant with good oral hygiene. * The subject has an edentulous mandible or failing mandibular dentition providing sufficient bone in the interforaminal where a fixed restoration on three (3) implants is regarded as an appropriate treatment solution. * The subject has an osseous architecture enough to receive three implants with a length of at least 11.5 mm and a diameter of 5 mm in the interforaminal (e.g. jaw volume B, C or D; inter foramina distance at least 20 mm; buccal/lingual width at least 6-7 mm, vertical height after leveling bone sufficient to receive an implant of at least 11.5 mm length). * The subject has a jaw curvature that fits to the prefabricated framework design. * Implants will be placed in healed or extraction sites (clinical stability has to be ensured). * The implant sites are free from infection and extraction remnants. * The subjects as well as the implant sites fulfill the criteria for early loading. Smokers that have reduced their consumption may be included after a certain test phase (e.g. test phase for reduction from 2 to 1 packages of cigarettes should be at least 6 months). Class II inter-jaw relation patients are not an exclusion criteria per se. Based on the individual judgment of the clinician those patients may be treated. Subject inclusion criteria at time of surgery * After bone leveling sufficient mandible bone volume in the interforaminal present for three (3) implants with a length of at least 11.5 mm and a diameter of 5 mm. * After bone leveling the jaw curvature does fit to the prefabricated framework. * The implant sites are free from infection and extraction remnants. * The subject as well as the implant sites fulfill the criteria for early loading. Exclusion Criteria: * The subject is not able to give her/his informed consent of participating. * Health conditions, which do not permit the surgical (including anesthesia) or restorative procedure. * Reason to believe that the treatment might have a negative effect on the subject's overall situation (psychiatric problems), as noted in subject records or history. * Any disorders in the planned implant area such as previous tumors, chronic bone disease or previous irradiation. * Alcohol or drug abuse as noted in subject records or in subject history. * Smoking of more than 1 package of cigarettes per day (\> 20 cigarettes or equivalent). * Uncontrolled diabetes, i.e. a subject with diagnosed diabetes that has a history of neglecting doctor's recommendations regarding treatment, food and alcohol intake or A1c level above 8%. * Bisphosphonate therapy - based on individual judgment of the clinician (if intravenously administered or too high oral doses recently before surgery and during follow-up period). * Pathologic occlusion, e.g. severe bruxism or other destructive habits. * Lack of opposing dentition or unstable occlusion. * Ongoing infections, endodontic or periodontal problems in opposing teeth or implants. * Subject shows an unacceptable oral hygiene. * Subject has allergic or adverse reactions to the restorative material.