Twenty one patients with deficient posterior maxilla and alveolar bone height ≤ 5mm were included.Those patients randomly divided into 3 equal groups:

1. Group 1: 7 patients treated by osteotome closed sinus lift with bone grafting (xenograft) and implant placement.
2. Group 2: 7 patients treated by densah burs(Versah, Jackson, MI, USA) sinus lift with bone grafting (xenograft) and implant placement.
3. Group 3: 7 patients treated by piezoelectric (Piezotome; Satelec) crestal sinus lift with bone grafting (xenograft) and implant placement.

Patients have been asked asked to use 0.12% chlorhexidine digluconate rinse, and Povidone iodine solution will be used to perform extraoral antisepsis. After administration of local anesthesia at the implant site, a full thickness flap was elevated to expose the crest of alveolar ridge. A pilot drill will be used to start the osteotomy preparation, which should be ended 1mm short of sinus floor.

In group 1; (closed sinus lifting with Osteotome): The drills can be sequentially used to widen the osteotomy site to the same level (1 mm short of the sinus floor), an osteotome of diameter a little less than the planned implant body, will be inserted in the prepared osteotomy site and gently tapped to reach the same level, the osteotome will be tapped gently to fracture up the sinus floor.

In group 2; (closed sinus lifting with densah drills): Change the drill motor to reverse-densifying Mode (counterclockwise drill speed 800-1500 rpm with copious irrigation), Begin with the densah bur (2.5mm) until 1 mm short of the sinus floor, use the next wider Densah Bur (3.0mm) in the same mode and advance it into the previously created osteotomy with modulating pressure and a pumping motion. When feeling the haptic feedback of the drill reaching the dense sinus floor, modulate pressure with a gentle pumping motion to advance past the sinus floor in 1 mm increments, the next wider densah drills advance in the osteotomy.

In group 3: The initial osteotomy will be performed with a 2-mm twist drill to remove the cortical bone, then the intralift tips (Intralift; TKW1, TKW2, TKW3, TKW4, TKW5; Satelec). TKW1 to TKW4 tips have diameters of 1.35 mm, 2.1 mm, 2.35 mm, and 2.8 mm and will be used to gradually widen the access canal to the Schneider membrane, gentle pressure will be applied on the tips to deepen the pathway, and a sterile spray (80 mL/min) cooling the tips to avoid heat injury. The TKW5 tip will be then inserted into the access canal, and the ultrasonic activation for 5 seconds with internal irrigation of 40 mL/min and repeated at 50 mL/min and then 60 mL/min. The sinus membrane will be pushed upward by the hydraulic pressure, the floating of the sinus membrane will be evaluated, and then the TKW4 (Ø 2.8 mm) will be used again to widen the access canal to the sinus membrane before plugging the bone graft.

For all groups: Clinical check for membrane still intact, blocking the patient's nostrils and asking the patient to blow through his or her nose. Xenograft was added as the grafting material and pushed to the sinus through the osteotomy site until the desired height of sinus elevation will be gained, the implant fixture will be inserted. Smart peg will be placed on implant and Ostell will be used to record ISQ. Cover screw will be placed on implant and flab will be sutured. Sutures were removed after 10 days.

Inclusion Criteria:

1. Young and adult patients of both sexes.
2. Patients exhibit class C residual bone height according to ABC sinus augmentation classification.(18)
3. The edentulous ridges are covered with mucoperiosteum free from signs of inflammation, ulceration or scar tissue.
4. Remaining natural teeth have good periodontal tissue support.
5. Occlusion showing sufficient inter-arch and intra-arch spaces for future prosthesis.

Exclusion Criteria:

1. Patients with systemic conditions that could influence the outcome of the therapy as: Pregnancy and Heavy smokers
2. Patients with systemic disease that may affect bone quality.
3. Uncooperative patients
4. Patients with active periodontal disease.
5. Patients with neglected oral hygiene.
6. Patients with limited mouth opening and unfavorable intermaxillary arch space.
7. Patients with maxillary sinus disease or previous sinus surgery.