Thirty two healthy implants will be selected from the outpatient clinic of the oral and maxillofacial department of Mansoura university to be included in this study for replacement of lost posterior teeth with limited bone width.

Inclusion Criteria:

• Patient age 18 years old and older.
• Patient's cooperation, motivation and good oral hygiene.
• Atrophic posterior mandible of horizontal alveolar dimension range between 3 - 6 mm at the crest, with minimum 10 mm vertical height from the alveolar crest to the superior border of the inferior alveolar canal.
• Absence of undercuts in buccal aspect of the ridge.
• Favorable occlusion and no parafunctional habits.
• Patients able to comply with the required recall visits.
• No gender preface in selection of the patients.
• Acceptable inter-arch space for the future prosthesis.

Exclusion Criteria:

• Any pathological condition at the site of surgery.
• Patients with systemic diseases that contra-indicate the surgical procedure such as uncontrolled diabetes mellitus, bleeding disorders, serious osseous disorders, and mental disorders.
• Patient taking drugs that could affect bone healing process as immunosuppressive drugs and bisphosphonates.
• Heavy smoking and alcoholism.
• Parafunctional habits such as bruxism and clenching.
• Signs of acute infection or pus discharge.
• Untreated periodontal disease or bad oral hygiene.