The objective of this study is to compare the primary stability of implant sites prepared using conventional drilling, osseodensification (Densah bur), and osteotome preparation techniques, and to evaluate the influence of these methods on implant success rates in areas of low bone density.

in different conditions implants that lack primary stability is subjected to excessive micromotion that can lead to implant failure. This usually happens when dental implants pass the critical limit of micro-motion. Passing this critical limit can interfere with Osseo-integration and cause fibrous encapsulation of dental implant .

Implant Failure usually occurs in completely edentulous maxillae especially in the posterior area where bone quality is compromised.

Clinicians usually refer implants success rates to the difference in bone quality between mandible and maxilla. Higher failure rates seem to be associated with poor bone quality.

Primary stability is affected by several factors including Bone Quantity and quality, the Implant macro- and micro- design, and the used osteotomy technique.

Osteotomies are usually created using conventional drills, although the implant diameter must be slightly larger than the final drill to ensure primary stability However, this conventional drilling technique might be insufficient to provide the primary stability required for Osseo-integration in areas of low bone quality. Several site preparation techniques have been introduced to enhance primary stability in soft bone. Some clinicians used under-sized drilling however the efficiency of this technique is conditioned by decreasing osteotomy diameter by 10% of implant diameter.

Another method introduced by Dr. Robert Summer. This method uses bone condensers to densify bone through the condensation and expansion of spongy bone as it squeezes bone trabeculae laterally against the wall of implant bed at the site of osteotomy increasing the bone density and conserving osseous tissue around implants.

Recently Osseodensification (OD) was introduced as a novel implant site preparation technique that uses specially designed drills with large negative rake angles. When the drills are operated in a counterclockwise direction it acts as a non-cutting drill which is used to expand and compact bone against the osteotomy walls. This non-subtractive approach aims to increase the primary stability of the dental implants inserted into low-density bone compared with conventional drilling techniques. The drills also can be used as a cutting drill when operated in a clockwise direction according to the operator's need. This type of drill can improve bone density leading to improved implant primary stability, giving these drills the ability to cut and densify without the need for additional tools.

Ossoe-densification technique showed greater insertion torques, bone-to implant contact, and bone area fraction occupancy when compared to standard Drilling technique.

this study is comparing between the three different drilling techniques (conventional, osseo-densification, osteotome bone compaction) in enhancing insertion torque and isq values in posterior maxillary area.

the study also compare between the effect of these techniques on marginal bone loss with follow up 6 month after loading using cbct

Inclusion Criteria:

• Patients with low bone density (D3), (D4) Missing maxillary posterior teeth
• edentulous ridge should be 8 mm or more of bone height and bone width ≥ 7mm with adequate inter-occlusal space of at least 8mm,
• Patients with good oral hygiene or willing to improve their oral hygiene.

Exclusion Criteria:

• Patients with uncontrolled medical conditions that affect Osseo-integration.
• Patients receiving medications that contraindicate osteotomy.
• Heavy smokers.
• History of receiving irradiation in the head and neck region.

Blinding was maintained throughout the clinical trial for all data collection and outcome assessments. Insertion torque and Implant Stability Quotient (ISQ) values were recorded immediately, 3 months post-surgery, and 6 months post-loading by two independent examiners who were not involved in the surgical procedures and were blinded to patient allocation. Additionally, radiographic outcomes-specifically marginal bone loss evaluated on CBCT images-were assessed by an independent professional who was strictly