Degradation Characteristics Research Of Two Kinds Of Platelet Rich Fibrin

Objective:By comparing and observing the degradation characteristics of fibrinPlatelet-Rich fibrin(PRF)and Advanced Platelet-Rich fibrin(A-PRF)in vitro and in vivo,evaluate the clinical value and direction,so as to provide some references for the clinical.Methods: 1.The degradation experiment in vitro : 10 volunteers each draw two tube elbow venous blood to separate A-PRF and PRF membrane.Then immerse in artificial saliva with co2 incubator,record physical state and measured the weight of the specimens ever day.2.The degradation experiment in vivo: 36 Japanese big ear rabbits were randomly divided into A-PRF group(A group)and PRF group(B group),each rabbit draw two tube of blood for the preparation of A-PRF or PRF.The membranes clip into 6 mm diameter circular.The animal model was established by operating on palate.Creating circular mucosal perforations along the palatal midline from the front of maxillary rear incisors 4mm by using 5mm ring cutter,separating the mucosal tissues with 1 mm around the hole.Creating angular mucosal flap with 5 mm side length 2 mm at the bottom of the circular mucosal perforation.A1 group:A-PRF membrane were placed under the circular mucosal perforations.B1 group:PRF membrane were placed under the circular mucosal perforations.A2 group:A-PRF membranes were placed under the mucosal flap.B2 group:PRF membranes were placed under the mucosal flap.Suturing the wound.A1/B1 were exposed group,A2/B2 were non exposedgroup,each group had 18 experimental samples.The change of two membrane materials were evaluated by morphological observation,measured the weight,HE staining,SEM study in the 3,5,7,10,14 and 21days after 3 animals were sacrificed.Results: 1.The degradation experiment in vitro:(1)The shortest degradation time of A-PRF membrane were 8 days.In 17 days,all A-PRF membrane were fully degraded.The shortest degradation time of PRF membrane were 10 days.In 14 days,all A-PRF membrane were fully degraded.(2)The difference between the degradation speed of A-PRF and PRF membrane were statistically significant(P < 0.05).2.The degradation experiment in vivo:(1)Morphological observation: the wound inflammatory reactions of APRF and PRF groups were mild in the 5th days after operation,the non exposed group of two membranes had almost healed in the 7th days after operation,the exposed group of two membranes had almost healed in the 14 th days after operation.7th days after operation: membrane materials of B1 group was obviously absorbed and difficult to complete removed.10 th days after operation:B1,A1,B2 groups were took out difficultly;14th days after operation: A2 group were were took out difficultly,A1,B2 group had no visible membranes;21th days after operation: A2 group implanted membranes cannot be found.(2)the degradation situation: In 14 days postoperatively,A1 group has been fully biodegradable;In21 days,A2 group has been fully biodegradable;In 10 days postoperatively,B1 group has been fully biodegradable;In 14 days postoperatively,B2 group has been fully biodegradable.membrane degradation rate of A1,A2 groups in thefirst five time node had a statistical difference(P < 0.05).membrane degradation rate of B1,B2 groups has a statistical difference(P < 0.05)expect 3th days after operation(P = 0.066 > 0.05);degradation rate of A1,B1 groups had no statistical differences in 3th days after operation(P = 0.408 > 0.05);7th and 10 th days after operationhe,the difference between A1,B1 groups was statistically significant(P < 0.05);degradation rate between A2,B2 groups in five time node were statistically significant(P < 0.05).(3)SEM results: A-PRF and PRF membrane are mesh structure,connected by fork structure.In the degradation process,fibrin mesh structure gradual disintegration,characterized by fibrin rupture of cords,net between porosity increases,irregular mesh structure gradually forming,membrane degradation into pieces,finally observe no obvious reticular structure.(4)HE staining(inflammatory score results): 3th,5th,7th days after operation,A1 group was higher than A2 group with significant difference(P <0.05),B1 group was higher than B2 group with significant difference(P < 0.05).Conclusion: 1.A-PRF and PRF membrane can be degraded in the artificial saliva,the degradation speeds of PRF membrane were faster than A-PRF membrane.2.A-PRF membrane in the oral environment will accelerate the degradation of membrane.3.Exposed in rabbit mouth,the degradation speeds of A-PRF membrane were slower than the PRF membrane.4.A-PRF and PRF membrane cannot as barrier membrane used in GBR technique alone.5.The degradation of A-PRF and PRF membrane were the degradation of fibrin and the collapse of the three-dimensional network structure.6.A-PRF and PRFmembrane exposed to the oral environment prone to bacterial infection,aggravating the inflammatory response,speed up the degradation of the membrane.