Aim: The present study was performed to evaluate the use of L-PRF and L-PRF mixed with particulate xenograft as alveolar ridge preservation materials after extraction of a tooth with chronic infection. Evaluation of the buccolingual dimensional changes of alveolar ridge was the primary objective while the secondary objectives were evaluation of the quality of regenerated bone histomorphometrically and assessment of implant stability.

Subjects and methods: This is a randomized controlled clinical trial in which thirty patients were randomly distributed into three groups. Group 1: Ten extraction sockets where alveolar ridge preservation was performed using L-PRF plug. Group 2: Ten extraction sockets where alveolar ridge preservation was performed using L-PRF mixed with particulate xenograft. Group 3: Ten extraction sockets where alveolar ridge preservation was performed using xenograft and collagen membrane. Evaluation of the alveolar ridge dimensional changes was performed radiographically. Histological and histomorphometrical assessment of the regenerated bone was also performed.

Results: Regarding alveolar ridge buccolingual changes radiographically , The highest mean percent decrease was recorded in L-PRF group with the least value recorded in L-PRF mixed with xenograft group. Regarding the Area fraction of newly formed bone and osteocytes count , The highest mean value was recorded in L-PRF mixed with xenograft group with the least value recorded in L-PRF group.

Conclusion: L-PRF mixed with xenograft group showed better dimensional and histological outcomes in alveolar ridge preservation in comparison to L-PRF alone or xenograft and collagen membrane.