Ridge Preservation Applying A Novel Hydrogel For Early Angiogenesis And Osteogenesis Evaluation:An Experimental Study In Canine

Background: Ridge preservation is universally acknowledged as the conventional method for the post-extraction healing yet there are no standard materials for the ideal healing outcome.Methods: Among six beagle dogs,mesial roots of left and right premolars and second molar(PM3,PM4 and M2)were extracted and distal roots were retained and grafting materials were filled randomly applying one of the following protocols: i)Blank group;ii)DBBM group;iii)DBBM+i-PRF group;iv)GNPs group;v)GNPs+iPRF group.At the time-points of 2 and 8 weeks postoperation,the animals were sacrificed for relatively histological and radiographical analysis.Results: According to Micro-CT outcomes,all grafting materials maintained the alveolar ridge compared to Blank group.Specifically,GNPs+i PRF significantly decreased whole blood clotting time(94.33 ± 3.51 s)and produced the most blood vessels area(1.44 ± 0.11%),woven bone(36.16 ± 0.51%)(p <0.05)and low osteoclast activity(4.67 ± 0.12%)in extracted socket at 2 weeks postoperation and remarkably generated corticalization on the alveolar ridge crest at 8 weeks postoperation according to histological results.Conclusions: GNPs+i-PRF promotes blood clotting along with angiogenesis/osteogenesis at an early time-point and subsequently creates favorable cortical bone at the alveolar ridge crest as to achieve the later goal of implantation,and thus it can be considered as the candidate treatment for ridge preservation.