Osseodensification Plus Platelet Rich Fibrin With Simultaneous Implant Installation in Closed Sinus Lift

12 patients with indirect sinus lift will be selected with RBH\>5mm , surgical procedure =osseodensification + Prf+ implant . 1. versah drilling system (osseodensefication technique )will be used , moreover Prf will be prepared by Blood collected in PRF tubes from patients then centrifuge (1300rpm ,14min ) . 2. primary stability will be measured using Resonance Frequency Analysis by Osstellimmediately and after 6 Mn . 3. CBCT will be taken before surgery , perioapical x-ray immediately after surgery and CBCT at 6m follow up to be apple to see the differences regarding bone quality and volume.