A new biological approach to guided bone and tissue regeneration

A new insight of Platelet-Rich Fibrin clots morphology and their elemental composition

This study analyzed the architecture of Platelet-Rich Fibrin (PRF) clots and assessed their elemental composition in order to provide new insight into this biomaterial. Five surplus PRF clots (2,700 RPM, 12 min.) donated by patients (63.6 ± 12.3 years old) were prepared for use in dental clinical procedures. The internal three-dimensional morphology of the red zones and the thirds of the yellow zones of the clots were analyzed by Variable Pressure Scanning Electron Microscope (VPSEM) after sample preparation by two methods: 1. Fixation (2.5% gluataraldehyde); and 2. Fixation with subsequent partial removal of extracellular elements (8 N, HCl). Semi-quantitative elemental analysis was performed by energy-dispersive X-ray spectrometry (EDX). VPSEM analysis showed erythrocytes in both the red zone and the yellow zone, which consisted mainly of fibrin. Removal of extracellular elements enriched the morphology of both zones; the organization of the fibrin was observed to differ in the thirds of the yellow zone, with increasing density and organization to distal. The elements that compose organic substances (C-Carbon, N-Nitrogen, O-Oxygen, Na-Sodium and P-Phosphorus) and halogens (Cl-Chloride and S-Sulfur) were detected; the highest concentrations were of C, followed by O (p < 0.05), in the proximal region of the fibrin. The results of the present study suggest organization of fibrin in the PRF clot, and also reveal the distribution of the elements present in the different regions of the clot. Improved understanding of these characteristics may favor the use of this biomaterial by increasing its efficiency and functionality.

Systematic Comparison of the Effect of Four Clinical-Grade Platelet Rich Hemoderivatives on Osteoblast Behaviour

Hemoderivatives have utilized in an empirical manner, driven by clinical considerations, leading to the development of a plethora of manufacturing protocols. The purpose of this study was to investigate the composition and bioactivity of four common clinical-grade hemoderivates prepared using standardised methods. Four different hemoderivatives were obtained from sheep blood and divided into two groups: A-PRF/i-PRF (fresh) and P-PRP/L-PRP (anticoagulated). Thrombus (CLOT) was used as a control. Thrombocyte quantification, growth factor composition (IGF-I, VEGF, PDGF-BB, BMP-2), cell viability, migration and mineralization assay were evaluated. Platelet recovery was superior for L-PRP followed by P-PRP. A significant cumulative release of IGF-I and PDGF-BB was noted for A-PRF and L-PRP groups at early time points. Similar release profiles of BMP-2 and VEGF were noted in all protocols. Cell viability and migration assay have demonstrated a detrimental effect when the concentration was ≥60%. Moreover, at Day 21, i-PRF have demonstrated superior mineralisation properties when compared to all groups. A negative impact of A-PRF was demonstrated at high concentrations. Despite its low content in growth factors, i-PRF was the best performing blood product for inducing osteoblast mineralisation, and therefore could be the candidate of choice for utilisation in bone tissue engineering applications.

Use of Platelet-Rich Plasma and Platelet-Rich Fibrin in Dentistry and Oral Surgery: Introduction and Review of the Literature

Platelet concentrates, mostly represented by platelet-rich plasma and platelet-rich fibrin, have gained significant interest in various medical and oral disciplines because of their potential to stimulate and boost regeneration of hard and soft tissues. Prepared from the patient’s own blood, they have been tested and used in various different surgical fields including oral and maxillofacial surgery. The effects of these biomaterials are described to be a result of the large concentration of platelets which contain a wide range of growth factors. The aim of this article is to introduce the principle and function of these platelet concentrates, to review their preparation, and to provide a comprehensive examination of the published oral and maxillofacial literature on this subject.

Platelet-rich fibrin and collagen membrane in the preservation of the alveolar bone: Feasibility of the elemental inorganic composition and scanning electron microscopy analysis

The success of dental implants is related to the amount, quality, and composition of the alveolar bone. The placement of platelet-rich fibrin (PRF) clot associated with a resorbable collagen membrane (RCM) in a postextraction alveolus is a technique used for ridge preservation. This case report study analyzed the ultrastructural characteristics of cross-sectioned alveolar bone that received PRF and RCM using scanning electron microscopy and the inorganic composition using "energy dispersive X-ray spectrometry," in order to explore the feasibility of this method to clinical studies. Three alveolar bone samples from two male patients (37 and 58 years old), obtained in the procedure of placing the dental implant, were analyzed. Two bone samples previously received PRF and RCM (M37 and M58), the third sample represented a physiological bone formation without treatment (M37-control). The bone sample M37 showed irregularly shaped islets of calcified material intermingled with connective tissue. The other samples, from the 58-year-old patient with PRF and RCM (M58); and the other untreated bone sample from the same 37-year-old patient (M37-control) showed similar ultrastructural morphology with trabecular conformation without islets agglomerations. The inorganic composition analysis showed higher concentrations of calcium and phosphorus in both samples treated with PRF and RCM in comparison to the untreated bone sample. The Ca/P ratio was higher in the M37 sample compared to the others samples. The results showed morphology and inorganic composition differences among the treatments used, suggesting that this method is feasible to analyze parameters of the alveolar bone tissue.

Platelet-Rich Plasma Promotes Axon Regeneration, Wound Healing, and Pain Reduction: Fact or Fiction

Platelet-rich plasma (PRP) has been tested in vitro, in animal models, and clinically for its efficacy in enhancing the rate of wound healing, reducing pain associated with injuries, and promoting axon regeneration. Although extensive data indicate that PRP-released factors induce these effects, the claims are often weakened because many studies were not rigorous or controlled, the data were limited, and other studies yielded contrary results. Critical to assessing whether PRP is effective are the large number of variables in these studies, including the method of PRP preparation, which influences the composition of PRP; type of application; type of wounds; target tissues; and diverse animal models and clinical studies. All these variables raise the question of whether one can anticipate consistent influences and raise the possibility that most of the results are correct under the circumstances where PRP was tested. This review examines evidence on the potential influences of PRP and whether PRP-released factors could induce the reported influences and concludes that the preponderance of evidence suggests that PRP has the capacity to induce all the claimed influences, although this position cannot be definitively argued. Well-defined and rigorously controlled studies of the potential influences of PRP are required in which PRP is isolated and applied using consistent techniques, protocols, and models. Finally, it is concluded that, because of the purported benefits of PRP administration and the lack of adverse events, further animal and clinical studies should be performed to explore the potential influences of PRP.