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Purpose: This study analyzed the concentrations of platelets and growth factors in platelet-rich plasma (PRP), which are likely to depend on the method used for its production. Materials and Methods: The cellular composition and growth factor content of platelet concentrates (platelet-rich plasma) produced by six different procedures were quantitatively analyzed and compared. Platelet and leukocyte counts were determined on an automatic cell counter, and analysis of growth factors was performed using enzyme-linked immunosorbent assay. Results: The principal differences between the analyzed PRP production methods(blood bank method of intermittent flow centrifuge system/platelet apheresis and by the five point-of-care methods) and the resulting platelet concentrates were evaluated with regard to resulting platelet, leukocyte,and growth factor levels. The platelet counts in both whole blood and PRP were generally higher in women than in men; no differences were observed with regard to age. Statistical analysis of platelet-derived growth factor AB (PDGF-AB) and transforming growth factor Β1 (TGF-Β1) showed no differences with regard to age or gender. Platelet counts and TGF-Β1 concentration correlated closely, as did platelet counts and PDGF-AB levels. There were only rare correlations between leukocyte counts and PDGF-AB levels, but comparison of leukocyte counts and PDGF-AB levels demonstrated certain parallel tendencies. Conclusions: TGF-Β1 levels derive in substantial part from platelets and emphasize the role of leukocytes, in addition to that of platelets, as a source of growth factors in PRP. All methods of producing PRP showed high variability in platelet counts and growth factor levels. The highest growth factor levels were found in the PRP prepared using the Platelet Concentrate Collection System manufactured by Biomet 3i. Int J Oral Maxillofac Implants 2012;27:762-769. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to compare a new method for the production of platelet-rich plasma (PRP), the plasma-rich-in-growth-factors kit (PRGF kit; G.A.C. Medicale San Antonio, Vitoria, Spain), with an established method, the Platelet Concentrate Collection System (PCCS; 3i/lmplant Innovations, Palm Beach Gardens, FL) with respect to resulting cellular and growth factor contents. Materials and Methods: Whole blood was drawn from 51 healthy donors (20 men, 31 women) aged 19 to 59 years (mean ± SD 35.12 ± 9.65 years), and PRP was prepared by both methods. Results: Platelet counts differed significantly (signed rank test, P < .001 for all) between the donor blood (274,200 ± 54,050/μL), the PCCS PRP preparation (1,641,800 ± 426,820/μL), and the PRGF kit PRP preparation (513,630 ± 139,470/μL). The PCCS concentrated leukocytes (whole blood, 6,992 ± 2,011/μL; PCCS PRP, 14,153 ± 7,577/μL), while the PRGF kit produced a leukocyte-poor PRP (65 ± 108/pL). Higher concentrations of transforming growth factor /β1 (TGF-/β1) and platelet-derived growth factor AB (PDGF-AB) were found in the PCCS PRP (TGF-/β1, 290 ± 95 ng/mL; PDGF-AB, 157 ± 62 ng/mL) than in the Anitua PRGF kit PRP (TGF-[β1, 73 ± 26 ng/mL; PDGF-AB, 47 ± 21 ng/mL). Statistical analysis showed significant differences (P < .001 for TGF-[β1 and P < .01 for PDGF-AB). Discussion: The results of this study and some data in the literature indicate that the content of growth factors in PRP can vary tremendously, depending on the system used for the preparation of PRP. Conclusion: PCCS collects more platelets and leukocytes than the PRGF kit. This results in significantly higher growth factor levels. Further in vivo studies are needed to determine whether this results in a clinically different biologic effect. INT J ORAL MAXILLOFAC IMPLANTS 2005;20:118-123 [ABSTRACT FROM AUTHOR]

Purpose: Potential treatments using autologous thrombocyte growth factors are an important reason to improve methods for isolating platelet-rich plasma (PRP). Two methods for extracting PRP directly by the surgeon are currently available; this study was conducted to compare the growth factor levels in the resulting PRP. Materials and Methods: Whole blood was drawn from 46 healthy donors (17 men, 29 women) aged 20 to 59 years (29.9 ± 7.8). PRP was then separated from each sample by both the PCCS (3i) and Curasan (PRP Kit, Curasan) methods. Results: The growth factor content differed significantly for TGF-β1 (PCCS 467.1 ng/mL; Curasan 79.7 ng/mL) (sign test P < .0001) and PDGF-AB (PCCS 251.8 ng/mL; Curasan 314.1 ng/mL) (P < .0001); this was less significant for IGF-I (PCCS 91.0 ng/mL; Curasan 69.5 ng/mL) (P < .02). The higher platelet count in the PCCS PRP (PCCS 2,232,500/μL; Curasan 1,140,500/μL) seemed to correlate with a higher level of TGF-β1 (Spearman's correlation coefficient, rS = 0.7), whereas the higher leukocyte count in the Curasan PRP (PCCS 15,300/μL; Curasan 33,150/μL) had only a minor correlation with higher levels of PDGF-AB (rS = 0.46). Discussion: The PCCS end product has both a higher platelet count and a higher total content of the growth factors investigated. Nevertheless, the biologic effect of the evaluated growth factor levels remains unknown. The amount of PRP necessary to achieve the intended biologic effects still remains unclear. Conclusion: PRP contains growth factors in high concentrations. Precise predictions of growth factor levels based on the thrombocyte counts of whole blood or PRP appeared limited. There are different sources for growth fators (platelets, leukocytes, plasma). [ABSTRACT FROM AUTHOR]

An important reason to improve methods of isolating platelet-rich plasma (PRP) is the potential use of autologous platelet growth factors. In addition to discontinuous plasma separation, a second method for extraction of PRP has now become available, which can be performed directly by the surgeon. In this study, the suitability of the 2 methods of producing PRP was compared. Whole blood was drawn from 158 healthy donors (112 men, 46 women) aged 20 to 62 years (mean 34, SD 10). The PRP was separated by the discontinuous plasma separation method (by the blood bank) or by the so-called "buffy coat" method (the "self-concentration" method, analogous to the PRP Kit, Curasan, Kleinostheim, Germany). Platelet counts differed significantly according to donor blood (median men 237,500/μL, women 272,000/μL), blood bank PRP preparation (median men 1,302,000/μL, women 1,548,500/μL), and self-concentrated PRP (median men 944,000/μL, women 1,026,000/μL). The platelet concentration of the blood bank PRP correlated with the platelet count in the donor whole blood (Spearman's correlation coefficient rS = 0.73). However, there was no significant correlation between the platelet count of self-concentrated PRP and donor whole blood (rS = 0.22). Significant but irrelevant influences of sex on platelet concentration were found, but no influence of age was detected. [ABSTRACT FROM AUTHOR]

Background: There is a lack of clinical studies on the self-aligning attachment system (Locator®; Zest Anchors, Inc. homepage, Escondido, CA, USA) for two-implant-retained overdentures in the edentulous mandible. Therefore, a comparison of the Locator with two traditional designs (a rotational gold matrix and a rubber O-ring type) in clinical 1-year use was conducted. Materials and Methods: From 2003 to 2007, 60 patients received two Osseotite® TG Standard implants (BIOMET 3i Implant Innovations, Palm Beach Gardens, FL, USA) in the intraforaminal area of the edentulous mandible. The implants were left unloaded for 3.5 months, randomized to three different attachment systems, and loaded through a mandibular overdenture. Twenty-three patients received a self-aligning attachment system (Locator) and 33 patients a ball attachment (Dal-Ro®[BIOMET 3i Implant Innovations] n = 25; TG-O-Ring®[Cendres & Metaux SA, Biel-Bienne, Switzerland] n = 8). After 12 months of delivery of the overdentures, the oral situation was evaluated: prosthodontic maintenance and biologic complications, subjective patients' experience, and oral health-related life quality (Oral Health Impact Profile [OHIP-G 49]). Results: After 1-year of clinical service, 8 of 120 implants were lost (9.6%). The Locator system brought up 34 prosthetic complications, especially the need for change of the male parts or activation because of loss of retention. The TG-O-Ring patients showed 14 complications, most of them the change of the O-Rings. The patients with the Dal-Ro abutment had seven minor complications in 12 months of clinical use. Biologic complications and patients' oral health-related life quality showed no significant difference among the three experimental groups. Conclusions: Prosthodontic maintenance was restricted to loss of retention for all systems. Within the observation period of this study, the self-aligning attachment system showed a higher rate of maintenance than the ball attachments. The patients' oral health-related life qualities as well as the biologic parameters do not differ when using the three abutment systems. [ABSTRACT FROM AUTHOR]

Platelet concentrates (PC) are increasingly used to increase bone regeneration in pre-prosthetic surgery. Although it is generally appreciated that certain growth factors (PDGF, TGF, EGF, and ECGF) are present in thrombocyte preparations, relatively little is known about these components in quantitative terms. The study reported here analysed the amounts of growth factors in PC produced under standard conditions from healthy volunteers. All the blood samples (237 in total) were analysed using Quantikine ELISA kits (R and D). The mean +/- SD platelet count in whole blood from these donors was 262,000+/-58,000/microl, while in PC produced by discontinuous cell separation it was 1.419,000+/-333,000/microl. The mean growth factor concentrations in PC preparations in ng/ml were as follows: PDGF-AB 125+/-55 ng/ml; TGF-beta1 221+/-92 ng/ml; IGF-I 85+/-25 ng/ml; PDGF-BB 14+/-9 ng/ml; TGF-beta2 0.4+/-0.3 ng/ml. These growth factor concentrations typically covered a 3-10 fold range: PDGF-AB 29-277ng/ml; PDGF-BB 2-33ng/ml; TGF-beta1 32-397ng/ml; TGF-beta2 0.1-1.2 ng/ml; IGF-I 40-138 ng/ml. Platelet counts in PC were slightly higher for women (Mann-Whitney Test all p < 0.001) than for men, while the concentrations of growth factors in PC exhibited no gender-related difference of any statistical significance.