Background: Dental implant therapy in the posterior maxilla may be difficult owing to limited bone height after dental extraction with sinus pneumatization. Several approaches for sinus floor elevation have been documented, and hence trans crestal sinus lifting with albumin platelet rich plasma.

Aim of the study: To compare between erythropoietin and albumin platelet rich fibrin transcrestal sinus lifting versus albumin platelet rich fibrin transcrestal sinus lifting using piezoelectric device in patients with atrophic maxilla.

Methods: This study will be carried out as a randomized

Inclusion Criteria:

• Residual bone height not less than 5 mm measured from crestal bone to sinus floor.
• Both genders.
• Good oral hygiene
• No previous surgery or radiation treatment on the maxillary sinus

Exclusion Criteria:

• Recent radiation therapy in maxilla.
• Uncontrolled systemic diseases such as diabetes mellitus.
• Heavy smoker (those who smoke ≥ 25 cigarettes a day).
• Alcohol abuse.
• Patient on anticoagulant drug
• Severe allergic rhinitis.
• Tumor or large cyst in the maxillary sinus.
• Oroantral fistula.
• Presence of acute or chronic sinus pathoses or sinus membrane perforation.(