Implants in the maxillary posterior region are associated with compromised bone in both quantity - notably in vertical dimension- and quality. Along with the fact that the posterior teeth are subjected to higher occlusal forces than the anterior teeth (Marianne Morand & Tassos Irinakis, 2007). In order to overcome these shortcomings, various procedures have been advocated including open and closed sinus lift (Nkenke E & Stelzle F, 2009; Schropp et al, 2003). The use of short implants is a valid alternative for these procedures (Wallace SS & Froum SJ, 2003) sparing the need of applying augmentation techniques with the associated increased time, morbidity and complexity of such procedures.

To overcome anatomical and physiological limitations, different sinus augmentation techniques with immediate or delayed (6-8 months post augmentation) implant placement have been proposed. The most common one is the sinus elevation with a lateral window approach. Although these protocols evoke a high level of success in augmenting the bone quantity (Nkenke E & Stelzle F, 2009; Schropp et al, 2003) many patients refuse them because of the invasiveness of the augmentative procedure, with obvious prolonged healing times and increased morbidity and costs (Fugazzotto, 2003; Bra¨gger et al, 2004; Toffler, 2004). An alternative therapy for restoring areas of limited bone dimension is the placement of short implants (Wallace SS & Froum SJ, 2003). ''Standard length implants'' are those of 10 mm in length and have been defined as the minimal length for anticipated success (Griffin TJ & Cheung WS, 2004).

Inclusion Criteria:

• Single edentuolous site at maxillary posterior region
• The available bone height below the maxillary sinus should be 7-8mm
• Patients ≥ 20 years old
• Bucco-palatal bone width should be ≥6mm
• Adequate interarch space
• Bounded, single

Exclusion Criteria:

• Patients with local pathological defects related to the area of interest.
• Patients with habits that may jeopardize the implant longevity and affect the results of the study such as alcoholism or parafunctional habits.
• Inadequate inter-arch space for implant prosthetic part
• Smokers
• pregnancy