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.