Fixed artificial teeth (dentures) for the upper jaw using two different techniques - A comparative trial

INTERVENTION: Intervention1: Zygomatic Implant: Branemark System Zygoma Ti‐Unite Implants RP from Nobel Biocare Gothenburg Sweden) having the following lengths: 30, 35, 40, 42.5, 45, 47.5, 50 and 52.5 mm Control Intervention1: Sinus lift: Sinus lift surgery will be performed on anterior and posterior maxillae and resultant space will be packed with bone substitute granules and covered with resorbable barriers. CONDITION: Completely edentulous maxillae with severe bone loss PRIMARY OUTCOME: Implant mobility assessed manually with the removed prosthesis and/or any infection dictating implant removal. Assessments will be done at 1, 3, 5, 7, 10, 15 years of loading. Implants, if not rotating, will be considered as successful.‐‐‐‐‐‐Timepoint: Assessments will be done at 1,3,5,7,10 years of loading SECONDARY OUTCOME: 1.Marginal bone levels on intra‐oral radiographs. ; 2. Oral Health Impact Profile OHIP‐14 (quality of life) ; 3. Patientsâ?? number of days with total or partial impaired activity assessed at delivery of the provisional prosthesis. ; 4.Time to function ; 5.Number of sessions with the dentist‐‐‐‐‐‐Timepoint: 1, 3, 5, 7, 10 and 15 years after loading. INCLUSION CRITERIA: Patients with fully edentulous and atrophic maxilla not having sufficient bone volumes for placing dental implants at all or when it is possible to place only 2 implants in the front area (minimal diameter 3.5 mm and length of 8 mm) as evaluated on TC scans. No more than 4 mm of bone height should be available subantrally.