Aim of the study: The aim of this study was to compare the regenerative potential of deproteinized bovine bone (xenograft) and platelet rich fibrin on implant primary stability in immediately placed mandibular premolar implants.
MATERIAL AND METHODS:
Twelve patients were selected from twenty five patients examined in the outpatient clinic of the implant clinic in Faculty Dentistry Cairo University

The patients fulfilled the following criteria: Presence of non-restorable mandibular premolar tooth due to trauma, caries, root resorption, root fracture, endodontic or periodontal failure, Male or female patients between the ages of 30 to 50. And Patient with Sufficient bone volume, good oral hygiene and nonsmokers.

Results:
The results showed that the measurements of primary stability for immediately extracted sockets with PRF and implant placement were greater than that with the xenograft; there was a statistically significant difference between the PRF group and the control group regarding measurements of primary stability.
The higher mean value was found in (PRF) group, while the lowest mean value was found in (Xenograft) group.
Conclusion:
From the results of the current study we can conclude that:
PRF provides better primary implant stability than xenograft as space filling material.
PRF is an effective material for management of jumping gap after immediately placed dental implants.
Further studies are recommended for long term evaluation of PRFas space filling material.