Partially, edentulous patients have a problem managing with a conventional prosthesis as they may hinder comfort, aesthetics, and speech.Placing dental implants in the posterior maxillary spaces is a challenging procedure due to maxillary sinus pneumatization which may be physiologic or caused by extraction of teeth  Also vertical bone loss after extraction is a major complicating factor which results in decreased vertical bone height.The bone in the posterior maxilla is soft and poorly organized so, to increase stability of dental implant in the posterior maxilla, adequate length should be used., for which maxillary sinus floor elevation is needed in these situations..Primary Stability of dental implant is an important factor in the success rate and healing of bone around dental implant (osseointegration).Surgical sinus floor augmentation can increase the ridge height by approximately 3-5 mm, facilitating simultaneous implant placement . The conventional sinus lift techniques made use of standard drilling protocol with burs for preparing the site for implant placement.Osseodensification is a recent innovation that has the added benefits of preserving bone during osteotomy preparation, increasing the primary stability of the implant, which in turn helps in better osseointegration and success of the implant.The procedure is characterized by low plastic deformation of bone that is created by rolling and sliding contact using a densifying bur that is fluted such that it densifies the bone with minimal heat elevation and allow for bone preservation and condensation through compaction autografting during osteotomy preparation, thereby increasing the bone density in the peri-implant areas and improving the implant mechanical stability.Despite the fact that there have been numerous studies on sinus membrane elevation ,the application of minimally invasive techniques /approaches has not been thoroughly documented. Not many human studies are available in literature where a comparison has been made between CAS KIT and the new technique of Osseodensification by Densah bur.Thus, this study aims to establish a comparison and highlight the merit (if any) of any one technique.

Primary Hypothesis::Is there any difference in the Implant stability, Crestal Bone Loss and Apical Bone Gain around Implants placed by two techniques: viz Crestal Approach Sinus kit and Osseodensification by Densah Bur for Indirect Sinus Lift

Null hypothesis:There is no significant difference in the Implant Stability ,Crestal Bone Loss and Apical Bone Gain around Implants Placed using Crestal approach sinus kit and Osseodensification technique by Densah Burs for Indirect Sinus lift procedure .