Evaluation Of Osteogenic Potential Of Platelet-rich Fibrin In Sinus Floor Elevation

Objective: To establish an animal model for maxillary sinus lift with Palatalwindow technique and evaluate the osteogenic potential of PRF in sinus floor elevationand provide the experimental basis for its clinical application.Methods: Select twelve healthy adult dogs from12to18months old forexperiment and after anesthesia, we extract2maxillary first molars from each dog.After12weeks of healing period, maxillary sinus floor of each dog augmentated6mmand simultaneous placement of implants and implanted different material. Dependingon the sacrificed time, all of adult dogs randomly divided into group A (4weeks) andgroup B (12weeks), Each group include6dogs. Depending on different bone graftmaterial,A and B groups canine maxillary sinus was further divided into six sub-groupsof A1、A2、A3、B1、B2、B3and each sub-group include4maxillary sinus. A1、B1group implanted PRF, A2、B2implanted autologous bone, A3、B3implantedautologous blood. These specimens were treated for gross observation，X ray andhistologic analysis and measured the bone height (Bone Height, BH) and bone density(Bone Density, BD) of the peri-implant with IPP6.0. Then using statistical softwareSPSS17.0to analysis these data.Results:1. Gross observation: Experimental animals with no deaths. In this study, a totalof24maxillary sinus, each A1and A2group have1cases of maxillary sinus mucosaperforation, but no found obvious inflammation, sinus mucosa was cuff wrappedaround the implant.24implants no one shedding. Wound healed around the implantand no gingival inflammatory response such as congestion and swelling, ulceration andpus. Removal of soft tissue and the metal rod gently tapping the implant at the top, thesound is crisp and implants grow well and have varying degrees of new bone within the sinus lift space.2. Radiographic observation: X-ray examination, no significant transmissionimages between the neck and around the base bone of all implants, suggesting goodosseointegration. The radiopaque strength and radiopacity area of bone tissue in groupB is greater than the group A. there is not clearly Radiopacity images in group A2andgroup A3; there is nebulous X-radiopaque image on implant top in group A1; there isnebulous X-radiopaque image on implant top in group B3and radiopacity is notstrong；there is radiopacity images on implant top in group B1and B2and the range issimilar,but the radiopacity strength in group B1is more stonger and is close to the basebone of the implant neck.(Figure9-14)3.Histological observation:The6groups’ Bone Height(BH) and Bone Density (BD) were:BH： A1,1.232±0.174mm； A2,0.812±0.134mm； A3,0.685±0.118mm；B1,3.218±0.345mm；B2,3.135±0.288mm；B3,1.898±0.157mm；BD： A1,62.92±6.24； A2,53.31±5.64； A3,50.39±4.12； B1,75.34±8.18；B2,65.06±5.88；B3,56.92±4.95。The results of Statistical analysis:BH：There are statistically significant differences (P <0.05) between group A1and A2,group A1and A3,group B2and B3,group B1and B3,group A1and B1,groupA2and B2, group A3and B3,the other groups were not statistically significant (P>0.05);BD：There are statistically significant differences (P <0.05) between group A1and A2,group A1and A3,group B1and B2,group B2and B3,group B1and B3,groupA1and B1,group A2and B2, the other groups were not statistically significant (P>0.05).4week, bone height and bone density of PRF group is superior to autologousblood group and autologous bone group, there are significant differences;12week,bone height and bone density of PRF group is superior to autologous blood group,there are significant differences, but compared with autologous bone group, only bonedensity has a significant difference, bone height has no significant difference.Conclusions:1. Whether implantation of autologous blood, autologous bone or PRF can get acertain amount of new bone in the sinus lift surgery. With the passage of time, theamount of bone is gradually increased. 2. Compared with autologous blood, PRF can effectively promote bone defectrepair, accelerated bone remodeling, improve the quality and quantity of boneregeneration; Compared with autogenous bone, PRF can improve the quality andquantity of bone regeneration in the short term, but with the time, increase bone massis not obvious.3.The animal experiment proves that it is feasible to only use of PRF in sinus liftto treat bone defects around implant.4. The animal model of sinus lift with Palatal window technique is feasible.