This study is aiming to evaluate bone gain and secondary stability in autogenous bone ring technique using trephine bur compared to control group of sticky bone.

The main prerequisite of achieving proper implant placement with ideal functional and proper restoration particularly in the posterior maxilla may compromise with violation to Schneiderian membrane especially in pneumatized maxillary Antrum when RBH < 4 mm, Conventional lateral sinus floor elevation (CLSFE) is one of the most common surgical techniques used for increasing the available bone volume to place implants and restore function and esthetics in severe atrophic maxilla.

The objective of this study was to evaluate sinus elevation with simultaneous implant placement using open technique and bone ring versus sticky bone clinically and radiographically in terms of secondary stability and bone gain around the implant

Inclusion Criteria:

• Patients with edentulous vertically deficient posterior maxillary ridge a 4-5 mm. height of alveolar bone.
• Both males as well as females without any active periodontal disease.
• All patients are in a good health with no systemic, immunologic or debilitating diseases that could affect normal bone healing.
• All selected patients are non-smokers and non-alcoholics.
• Patients are free from T.M.J troubles, abnormal oral habits such as bruxism.
• The edentulous ridges are covered with optimal thickness of mucoperiosteum with no signs of inflammation, ulceration or scar tissue.
• Remaining natural teeth have good periodontal tissue support and occlusion showed sufficient inter arch space for future prosthesis.

Exclusion Criteria:

• On the local level, patients with maxillary sinus diseases, former sinus surgery and unfavorable inter maxillary relationship will be excluded.
• General contraindications to implant surgery.
• Subjected to irradiation in the head and neck area less than 1 year before implantation.
• Untreated periodontitis.
• Poor oral hygiene and motivation.
• Uncontrolled diabetes.
• Pregnant or nursing.
• Substance abuse.
• Psychiatric problems or unrealistic expectations.
• Severe bruxism or clenching.
• Immunosuppressed or immunocompromised.
• Treated or under treatment with intravenous amino-bisphosphonates.
• Lack of opposite occluding dentition/prosthesis in the area intended for implant placement.
• Active infection or severe inflammation in the area intended for implant placement.
• Need of bone augmentation procedures at implant placement.
• Unable to open mouth sufficiently to accommodate the surgical tooling.
• Patients participating in other studies, if the present protocol could not be properly followed.
• Referred only for implant placement or unable to attend a 5-year follow-up.

This trial is considered a randomized double blind clinical trial due to the following:

1. The participant will be blinded to the technique that will be used during the surgical operation.
2. The outcome assessor will be blinded
3. The operator (DR.O.S.) will not be blinded for both techniques during the surgical operation, as the two techniques are different. (Dr. M.O.).

The purpose of double blinding procedure is to reduce assessment bias and to increase accuracy and objectivity of clinical outcomes.