Comparison of Early and Late Loading in the Edentulous Upper Jaw Using Cresco Prosthetic System on Straumann Implants

Inclusion Criteria: * Males and females must be at least 18 years of age. * Be edentulous in the maxilla and subjectively desire an implant supported screw retained FPD * The teeth at the implant site must have been extracted or lost at least 3 months before the date of implantation. * In the case of Guided Bone Regeneration(GBR) or Guided Tissue Regeneration (GTR) treatments, these procedures must have been completed at least 6 months prior to intended surgery date (to fulfil point 5). * Adequate bone quality and quantity at the six, minimum five, implant sites to permit the insertion of Straumann 4.1 and 3.3 mm diameter implants without the use of concurrent bone augmentation techniques. I.e. implant insertion sites must have sufficient bone height such that the implant will not encroach on vital structures and sufficient width that a minimum of 1 mm of palatal and buccal bone will remain. * Patients must be committed to participate in the study for three years follow-up examinations Exclusion Criteria: * Presence of conditions requiring chronic routine prophylactic use of antibiotics (e. g., history of rheumatic heart disease, bacterial endocarditis, cardiac valvular anomalies, prosthetic joint replacements) * Medical conditions requiring prolonged use of steroids * History of leukocyte dysfunction and deficiencies * History of bleeding disorders * History of neoplastic disease requiring the use of radiation or chemotherapy * Patients with history of renal failure * Patients with metabolic bone disorders * History of uncontrolled endocrine disorders * Physical handicaps that would interfere with the ability to perform adequate oral hygiene * Use of any investigational drug or device within the 30-day period immediately prior to implant surgery on study day 0. * Alcoholism or drug abuse * Patients infected with HIV * Patients who smoke more than 10 cigarettes per day or cigar equivalents, or who chew tobacco (not greater than 10 cigarette equivalents) * Conditions or circumstances, in the opinion of the investigator, which would prevent completion of study participation or interfere with analysis of study results, such as history of non-compliance, unreliability. * Local inflammation, including untreated periodontitis * Mucosal diseases such as erosive lichen planus * History of local irradiation therapy * Presence of osseous lesions * Unhealed extraction sites (less than 3 months post extraction of teeth in intended sites) * Bone surgery (bone grafts, guided tissue regeneration technique for bone enhancement) at implant placement. * Severe bruxing or clenching habits * Persistent intraoral infection * Patients with inadequate oral hygiene or unmotivated for adequate home care * Lack of primary stability of 1 or more implant(s) at surgery. In this instance the patient must be withdrawn and treated accordingly. * Insufficient bone * Other: Inability to place implants according to protocol requirements