2752 Comparative Investigation of VEGF, and ALP Expression in Topic: Basic research Comparative Investigation of VEGF, and ALP Expression in Titanium Prepared Platelet-Rich Fibrin (T-PRF) and Platelet-Rich Fibrin (PRF) Induced Bone Formation Mustafa Tunali, Gulhane Military Medical Academy Haidarpasa Training Hospital, Istanbul Turkey; Hakan Özdemir, School of Dentistry, Cumhuriyet University, Sivas Turkey; Zafer Küçükodacı, Gulhane Military Medical Academy Haidarpasa Training Hospital, Istanbul Turkey; Şeref Erziganlı, School of Dentistry, Bezmialem Vakıf University, Istanbul Turkey; Emre Barış, School of Dentistry Gazi University, Ankara Turkey; Serhan Akman, School of Dentistry Selcuk University, Konya Turkey; Erhan Firatli, School of Dentistry, Istanbul University,Istanbul Turkey 2752   VEGF Bone Positive Cells, % Intensity* Callus Positive Cells,% T-PRF 1 month 80 III 50 3 months 40 II - PRF 15 I 10 5 Control 70 30 Background and Aim We developed a novel platelet-rich product that we called titanium-prepared platelet-rich fibrin (T-PRF) (1). TPRF method is based on the hypothesis that it may be potentially beneficial if a titanium tube is used instead of a glass tube in the classical platelet-rich fibrin (PRF) method and titanium may be more effective at activating platelets than the silica activators used with glass tubes in Chouckroun’s PRF (2). This study aimed to compare the expression of vascular endothelial growth factor (VEGF) and alkaline phosphatase (ALP) in T-PRF and PRF induced bone formation in a rabbit calvaria model. Eighteen adult male New Zealand rabbits were used in the study. T-PRF , and PRF were used in the experimental groups. No materials were used in the control group. Half of the animals were sacrificed after 1 month, and the remaining animals were sacrificed after 3 months. New hard and soft healing tissue was examined by immunocytochemistry to localize VEGF, and ALP positive cells. T-PRF membrane remains were observed in the rabbit tissues after 1 month. There was higher active bone formation in the T-PRF group than in the other groups. More VEGF, and ALP positive cells were noted in the T-PRF group than in the PRF group after 1 month, and after 3 months. Methods and Materials Table 1. More VEGF positive cells were noted in the T-PRF, and control groups than in the PRF group. *Staining intensity was graded as 0 (negative), I (weak), II (modarate), and III (strong).   ALP Bone Positive Cells, % Intensity* Callus Positive Cells,% T-PRF 1 month 50 I 15 3 months 10 - PRF 1 5 Control 25 II Results Table 2. More ALP positive cells were noted in the T-PRF group than in the PRF group. *Staining intensity was graded as 0 (negative), I (weak), II (modarate), and III (strong). A B Figure 3. ALP positive cells were noted in the (A) T-PRF, and in (B) the PRF group after 1 month. Figure 1. VEGF positive cells were noted in the (A) T-PRF (x400), and in (B )the PRF (x200) group after 1 month. Conclusions A B Based on the results of this study, T-PRF membrane was able to remain in the rabbit tissues for at least 1 month, which was sufficient time for the initiation of formation of new bone. VEGF, and ALP could be two important factors in accelerating the bone healing events of T-PRF bone augmentation in a rabbit bone-healing model. References Tunalı M, Özdemir H, Küçükodacı Z, Akman S, Yaprak E, Toker H, Fıratlı E. A novel Platelet concentrate: titanium-prepared platelet-rich fibrin. Biomed Res Int. 2014;2014:209548. doi: 10.1155/2014/209548. Epub 2014 Jan 21. Tunalı M, Özdemir H, Küçükodacı Z, Akman S, Fıratlı E. In vivo evaluation of titanium-prepared platelet-rich fibrin (T-PRF): a new platelet concentrate. Br J Oral Maxillofac Surg 2013;5:438-43. Figure 2. VEGF positive cells were noted in the (A) T-PRF (x400), and in (B ) the PRF (x200), group after 3 months. Presented at the 93rd General Session & Exhibition of the IADR, 44th Annual Meeting of the AADR 39th Annual Meeting of the CADR; March 11-14 Boston, Mass., USA