The selected patients will be informed of the nature of the research work and informed consent will be obtained.

The control group ridge splitting with simultaneous implants using the conventional technique and study group ridge splitting with simultaneous implants using the piezo surgery.

• Pre operative procedures Patients of both groups will be subjected to CBCT.
• Intra operative procedures (for both groups) followed by CBCT will be taken for every patient after 4 months.
• Infiltration local anesthesia will be given to the patient (Articaine 4% 1:100 000 epinephrine).

Both the study and control group will receive:

• In Recipient site, incision of full thickness mucoperiosteal flap inorder to obtain, three-line pyramidal flap, followed by flap reflection.
• The defective site is reevaluated.
• Flap advancement using periosteal releasing incision.
• In the Study group: Piezo surgery bone inserts are used.
• In the Control group: Bone discs diameter are used.
• Followed by bone chisels.
• The point and pilot implant drills are used followed by the sequential use of bone expanders. Based on the preexisting bone, the defect morphology and bone quality. The implant is submerged below the alveolar crest.
• The fixture is inserted submerged below the alveolar bone crest followed by bone smoothening and roundation under external saline irrigation at recommended speed of 38000rpm and gear ratio 1:1 calibrated on fesiodespenser.
• Xenogenic bone particle size of 0.5 mm to 1mm is going to be condensed into the dead space.
• Recheck adequate flap advancement.
• Double line closure using horizontal mattress sutures followed by interrupted sutures on top to allow contact area and wound edge eversion.

-The selected patients will be informed of the nature of the research work and informed consent will be obtained then randomized in equal proportions between, control group ridge splitting with simultaneous implants using the conventional technique and study group ridge splitting with simultaneous implants using the piezo surgery.

• Pre operative procedures Patients of both groups will be subjected to CBCT (diagnostic for upper arch), Diagnostic wax-up and stent fabrication.
• Intra operative procedures (for both groups) followed by CBCT will be taken for every patient after 4 months.
• Scrubbing and draping of the patient will be carried out in a standard fashion for intra oral procedures.
• Infiltration local anesthesia will be given to the patient (Articaine 4% 1:100 000 epinephrine).

Both the study and control group will receive:

• In Recipient site, using 15C blade on Bard Parker handle incision of full thickness mucoperiosteal flap inorder to obtain, three-line pyramidal flap, reflection using mucoperiosteal elevator molt 9.
• The defective site is reevaluated after its primary evaluation on CBCT using UNC periodontal probe.
• Flap advancement using periosteal releasing incision inorder to allow later tension free flap closure.
• In the Study group: Piezo surgery bone inserts is used to cut crestal osteotomy in the center of the alveolar bone ridge bucco-lingual traversing the compact bone into the spongiosa Followed by two semi vertical osteotomies at least 1.5mm away from the adjacent teeth.
• In the Control group: Bone discs diameter 7mm mounted on contra angled 1:1 is used to cut crestal osteotomy in the center of the alveolar bone ridge bucco-lingual traversing the compact bone into the spongiosa Followed by two semi vertical osteotomies at least 1.5mm away from the adjacent teeth using bone discs diameter 6.5mm mounted on external irrigation straight hand piece.
• First, the spatula bone chisels are used to make sure of extension of osteotomies into the spongy bone in addition to, adequate free of the cut corners, followed by sequential use of tapered bi-angled bone chisels and hammering with bone mallet 3mm shorter than the length of the proposed implant to gain adequate 1ry stability with concurrent support of the buccal plate of bone as well as the mandible by the assistant.
• The point and pilot implant drills are used followed by the sequential use of bone expanders diameters 2.6, 3, 3.4, 3.8 to place an implant of diameter 3.7 or 4.1mm. Based on the preexisting bone, the defect morphology and bone quality. The implant is submerged about 2mm to 3mm below the alveolar crest to compensate for crestal bone resorption.
• Following partial immobilization of the buccal bone segment either book or island pattern. The fixture is inserted submerged below the alveolar bone crest by 2mm to 3mm. Followed by bone smoothening and roundation using large round diamond stone mounted on straight hand piece with external saline irrigation at recommended speed of 38000rpm and gear ratio 1:1 calibrated on fesiodespenser. To avoid soft tissue irritation.
• Xenogenic bone particle size of 0.5 mm to 1mm is going to be condensed into the dead space. To act as a scaffold for the formation of autogenous bone.
• Recheck adequate flap advancement by visualizing passive flap approximation, to allow tension free closure.
• Double line closure using horizontal mattress placed 5mm away from flap margins followed by interrupted sutures on top to allow contact area which is preferred to point contact and wound edge eversion.

Inclusion Criteria:

• Patients with mandibular residual alveolar bone height not less than 8 mm.
• Alveolar bone width from 5mm to 3mm.
• Both genders.
• At least single missing tooth.
• Previous failed implants.
• Tapered or cylinder cross sectioned alveolar bone defect pattern.

Exclusion Criteria:

• Heavy smokers more than 20 cigarettes per day.
• Patients with bone disease that may affect normal healing, example; hyperparathyroidism.
• Patients had radiotherapy and chemotherapy in head and neck.
• Patients had neoplasms in sites to be grafted.
• Patients with Metabolic diseases uncontrolled diabetic patients, Glycated hemoglobin (Hb A1c) more than 7 mg\dl.
• Pregnant females.
• Patients with Para functional habits, apprehensive and non-cooperative.
• Bone pathology related to the site to be grafted.
• Psychological problems, stress situation (socially or professionally), emotional instability, and unrealistic patients' expectations.
• Intraoral soft and hard tissue pathology.
• Systemic condition that contraindicates implant placement.
• Under the age of 18 years.
• Hourglass defects or defects with bone concavities and or undercuts.

The patients were randomly allocated into two groups utilizing Random Allocation Software version 2.0. then the allocation was concealed in opaque sealed envelopes. In the study group (A) Piezo Surgery inserts are going to be used to create alveolar bone osteotomies, while in the control group (B) bone discs are going to be used. All procedures were performed by one surgeon in both groups, the allocation was revealed to the operator just before the surgery. On the other hand, the patients, outcome assessor and the statistician who analyzed the collected data and performed the statistical analysis were blinded.