A comparative study of platelet-rich fibrin (PRF) and platelet-rich plasma (PRP) on the effect of proliferation and differentiation of rat osteoblasts in vitro

Histological evaluation of combined platelet-rich fibrin membrane and piezo-incision application in orthodontic tooth movement

The aim of this study was to evaluate the effect of platelet-rich fibrin (PRF) membrane on tooth movement in comparison with shunt control and piezoelectric surgery. Sixteen White Vienna rabbits were included in the study and divided into two groups. Reciprocal forces (20 g) were applied on the maxillary incisors by an orthodontic appliance. In group 1, PRF membrane was placed sub-periosteally on the distal alveolar bone surface of the right central incisors and the left side was kept as control. In group 2, piezo-incisions 3 mm in depth were performed and combined with PRF membrane on the distal alveolar bone surface of the right central incisors, while the left side was kept as control. All rabbits were euthanized on day 21 and bilateral alveolar bone segments from the distal regions were removed for histological evaluation. Isolated PRF membrane application increased the blood vessel (8.3 ± 1.0; P =  0.026), osteoblast (6 ± 0.8; P =  0.027), and osteoclast (2.3 ± 0.8; P =  0.026) counts significantly compared to shunt control. Combined application of PRF membrane + piezo-incision increased the blood vessel (15.3 ± 0.8; P =  0.027), osteoblast (9.8 ± 1.4; P =  0.026), and osteoclast (3.3 ± 0.8; P =  0.024) counts significantly compared to shunt control. The increases in blood vessel count and osteoblast cell count were more evident in the combined application group (both P =  0.002). PRF membrane application significantly increased bone turnover, and the combined application of PRF membrane + piezo-incision was found to be the best method for increasing bone turnover.

Study of platelet-rich fibrin combined with rat periodontal ligament stem cells in periodontal tissue regeneration

The objective of this study was to investigate the advantages and feasibility of periodontal tissue regeneration using platelet‐rich fibrin (PRF) combined with rat periodontal ligament stem cells (PDLSCs) for the first time. We first determined the effect of PRF on rat PDLSCs in vitro. We next conducted an in vivo study, in which a tissue engineering technique was performed to repair periodontal defects in five groups: a blank group, collagen group (implanted collagen membrane), collagen + cells group (implanted collagen membrane and rat PDLSCs), PRF group (implanted PRF membrane) and PRF + cells group (implanted PRF membrane and rat PDLSCs). PRF greatly enhanced cell proliferation, mRNA and protein expression levels of bone sialoprotein (BSP), osteocalcin (OC), and runt‐related transcription factor 2 (RUNX2) and activity of alkaline phosphatase (ALP) in vitro. Transplantation of PRF combined with rat PDLSCs resulted in higher expression of osteopontin (Opn), collagen I (COL1A) and RUNX2 at both 12 and 24 days after surgery. Micro‐computed tomography and histological analysis showed substantially more new bone formation in the PRF + cells group at 24 days after surgery. Based on these results, we discuss the role of PRF in the proliferation and differentiation of rat PDLSCs and suggest that PRF combined with rat PDLSCs provides a valuable tool for periodontal tissue engineering.

Influence of Fractionation Methods on Physical and Biological Properties of Injectable Platelet-Rich Fibrin: An Exploratory Study

Injectable platelet-rich fibrin (i-PRF) has been used as an autografting material to enhance bone regeneration through intrinsic growth factors. However, fractionation protocols used to prepare i-PRF can be varied and the effects of different fractionation protocols are not known. In this study, we investigated the influence of different fractions of i-PRF on the physical and biological properties derived from variations in i-PRF fractionation preparation. The i-PRF samples, obtained from the blood samples of 10 donors, were used to harvest i-PRF and were fractioned into two types. The yellow i-PRF fractionation was harvested from the upper yellow zone, while the red i-PRF fractionation was collected from both the yellow and red zone of the buffy coat. The viscoelastic property measurements, including the clot formation time, α-angle, and maximum clot firmness, were performed by rotational thromboelastometry. The fibrin network was examined using a scanning electron microscope. Furthermore, the concentration of growth factors released, including VEGF, TGF-β1, and PDGF, were quantified using ELISA. A paired t-test with a 95% confidence interval was used. All three viscoelastic properties were statistically significantly higher in the yellow i-PRF compared to the red i-PRF. The scanning electron microscope reviewed more cellular components in the red i-PRF compared to the yellow i-PRF. In addition, the fibrin network of the yellow i-PRF showed a higher density than that in the red i-PRF. There was no statistically significant difference between the concentration of VEGF and TGF-β1. However, at Day 7 and Day 14 PDGF concentrations were statistically significantly higher in the red i-PRF compared to the yellow group. In conclusion, these results showed that the red i-PRF provided better biological properties through the release of growth factors. On the other hand, the yellow i-PRF had greater viscoelastic physical properties. Further investigations into the appropriate i-PRF fractionation for certain surgical procedures are therefore necessary to clarify the suitability for each fraction for different types of regenerative therapy.

Concentrated growth factor exudate enhances the proliferation of human periodontal ligament cells in the presence of TNF‑α

The purpose of this study was to evaluate the effects of concentrated growth factor exudate (CGFe) on human periodontal ligament cells (hPDLCs) stimulated by tumor necrosis factor (TNF)‑α. From the peripheral blood of healthy donors, CGFe was prepared according to the Sacco protocol after 7 days of incubation. The hPDLCs were cultured by a tissue explant method and identified with anti‑vimentin and anti‑cytokeratin antibodies. Cells were subjected to four different treatments: i) Control; ii) TNF‑α (10 ng/ml); iii) CGFe (concentration 50%); and iv) CGFe+TNF‑α. The proliferation of hPDLCs was measured with Cell Counting Kit‑8 assays. Osteogenic differentiation and mineralization were determined by Alizarin Red S staining, alkaline phosphatase activity, western blotting and reverse transcription‑quantitative polymerase chain reaction. CGFe enhanced cell proliferation and upregulated ALP activity, the mineralization level, and osteogenic‑associated osteocalcin, runt‑related transcription factor 2 and Osterix gene expression in hPDLCs under inflammatory conditions induced by TNF‑α. The present study demonstrated that CGFe enhanced hPDLC proliferation and osteogenic differentiation in the presence of TNF‑α‑induced inflammation. As CGFe can be obtained from the venous blood of patients, it generates no immune reaction. Thus, it is more economical and beneficial to use CGFe in clinical periodontal regeneration practice than synthetic growth factors.

The Combined Effect of Bioactive Glass and Platelet-Rich Fibrin in Treating Human Periodontal Intrabony Defects - A Clinicoradiographic Study

Background:

Platelets are richest source for cytokine and growth factors which are two important components for the re-establishment of bone and maturation of the soft tissue.

Aims and Objective:

The additive effect of PRF along with a synthetic bone graft material in treating human intrabony periodontal defects has been evaluated in this study. The appropriate use of platelet-rich fibrin (PRF) as an alternate comfortable graft material to restore the lost periodontal tissues has been well documented and has given clinically promising outcome.

Materials and Method:

Platelet-rich fibrin (PRF) is prepared from patient's own blood which is autologous in nature. Perio Glas (PG) is an easy to use synthetic absorbable osteostimulative as well as osteoconductive bone graft material. The selected 30 sites were randomly divided into two groups such as Test (15 sites using PRF) and Control (15 sites without PRF).

Results:

At the end of Six months, the post-operative evaluations revealed significant reduction in PPD and gain in CAL. Radiographic evidence of bone formation was also noticed. The incorporation of PRF with synthetic bone graft (perioglas) produces effective and rapid periodontal regeneration with improved healing in intrabony osseous defects. The PRF group showed a mean Radiographic Defect Fill (RDL) of 1.24 ± 0.04 compared with 0.79 ± 0.07 of control group which is statistically significant.

Conclusion:

This combination technique can be used as an alternate grafting modality for the treatment of intrabony periodontal defects with satisfactory clinical consequences.

Comparative evaluation of growth factors from platelet concentrates: An in vitro study

Aim

The aim of the study was to compare and evaluate the various growth factors released for a period of 23 days from platelet rich fibrin (PRF) and platelet rich fibrin matrix (PRFM).

Materials and Methods

A total of 15 systemically healthy controls were recruited and 10 ml of blood sample was withdrawn from the individual. Following the standard centrifugation protocol, PRF and PRFM were prepared. The platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), fibroblast growth factor (FGF), transforming growth factor (TGF), and insulin growth factor (IGF) were evaluated for 23 days.

Results

The PDGF released from PRFM was statistically significant from PRF till the 15^th day of release. The VEGF too had an increased release up till the 15^th day from PRFM group as compared to PRF, but no statistically significant difference could be obtained. EGF from the 15^th day to 23^rd day had a greater release from PRFM group as compared to PRF group. FGF from 7^th day to 23^rd day had statistically significant difference in the PRFM group as compared to PRF group. TGF and IGF had statistically significant difference in PRFM group as compared to PRF group from 11^th day to 23^rd day and 1^st to 17^th day, respectively.

Conclusion

The initial and robust release of GFs was seen in PRFM group at earlier days, whereas a steady and constant release of six GFs could be appreciated from PRF group upto 23^rd day. Therefore, for a rapid and early healing and regeneration, both the platelet concentrates can be utilized in periodontal therapy.

Clinical and radiographic evaluation and comparison of bioactive bone alloplast morsels when used alone and in combination with platelet-rich fibrin in the treatment of periodontal intrabony defects-A randomized controlled trial

BACKGROUND

The present study aims to evaluate and compare the clinical and radiographic changes obtained through Bioactive Glass (BG) with and without autologous platelet-rich fibrin (PRF) in the treatment of intrabony defects in chronic periodontitis patients.

METHODS

The present study was a split-mouth randomized controlled clinical trial comprising 20 chronic periodontitis patients (mean age: 35.9 years) having at least one pair of bilateral intrabony defect. Group 1 included 20 sites treated with a combination of BG and autologous PRF whereas 20 sites in Group 2 were treated with BG alone. Probing pocket depth (PPD), clinical attachment level (CAL) and gingival recession (GR) were evaluated at 3 and 6 months and bone fill at 6 months by using cone beam computed tomography (CBCT) analysis. Primary study outcomes were changes in PPD, CAL, GR, and bone fill.

RESULTS

CAL gain was greater in Group 1 (5.05 ± 1.09 mm) when compared with Group 2 (4.2 ± 1.70 mm). Furthermore, a significantly greater bone fill was found in Group 1. At 6 months, statistically significant reduction in PPD in Group 1 and Group 2 was evident.

CONCLUSION

BG morsel when used in combination with PRF is found to be more effective in gain in CAL, reduction in PPD and achieving greater bone fill as compared with treatment with BG alone in periodontal intrabony defects and is indicative of enhanced periodontal regeneration.

The effect of adipose-derived mesenchymal stem cells and chondrocytes with platelet-rich fibrin releasates augmentation by intra-articular injection on acute osteochondral defects in a rabbit model

BACKGROUND

This study aimed to investigate the efficacy of adipose-derived mesenchymal stem cells (ADSCs), platelet-rich fibrin releasates (PRFr), and chondrocyte transplantation in rabbit acute osteochondral defects.

METHODS

Thirty rabbits were randomly assigned to five groups: untreated controls; ADSCs alone; PRFr alone; PRFr + ADSCs; and PRFr + chondrocytes. The critical size osteochondral defects in right knee femoral condyles were injected intra-articularly according to the groups, as listed. The experimental rabbits received treatments once a week for two weeks postoperatively. All evaluations were conducted for 14 weeks following surgery, and the regenerated cartilages were assessed by gross inspection and histological examination.

RESULTS

There were no complications encountered in any of the rabbits. The size of the defect decreased and the volume of repaired cartilage increased in the medial femoral condyles of the PRFr + ADSCs group. Relative to the ADSCs or PRFr group, histological examination demonstrated that the PRFr + ADSCs group had thicker hyaline cartilage-specific extracellular matrix. Grading scores revealed that PRFr + ADSCs injection had better matrix, cell distribution, and surface indices than other groups (P < 0.05). However, the histological scores reported for PRFr + chondrocytes on cartilage repair were similar to those of PRFr, and there were no significant between-group differences.

CONCLUSIONS

These findings showed that intra-articular injections of PRFr + ADSCs into the knee can reduce cartilage defects by regenerating hyaline-like cartilage without complications. This approach may provide an alternative method for functional reconstruction of acute osteochondral defects with an unlimited source of cells and releasates.

Biological activation of bone grafts using injectable platelet-rich fibrin

Platelet-rich fibrin (PRF) is gaining acceptance as a bioactive surgical additive in regenerative dentistry. However, PRF has only been available in gel or membrane form and is not suitable for injection. Recently, however, a liquid, injectable PRF has been introduced. This paper introduces the concept of injectable PRF and discusses its applications for biologic activation of bone grafts.

Sinus floor elevation with platelet-rich fibrin alone: A Clinical retrospective study of 1-7 years

Background

Several sinus floor elevation procedures for implant placement have been introduced. The present study aimed to evaluate the implants placed with Platelet-rich fibrin (PRF) alone in atrophic posterior maxillae and survival rates and the potential factors associated with implant loss.

Material and Methods

This retrospective study evaluated 71 implants in 34 patients after 1-7 years' follow-up time. Statistical models were used to determine the implant survival and the potential factors associated with loss.

Results

Overall, 7 implants were lost, and the cumulative survival rate at 7 years by implant-based and patient-bases analyses were 85.5% and 85.7%, respectively. The mean residual bone height (RBH) was 4.26 mm. The implant survival rate was significantly lower at RBH < 4 mm than RBH ≥ 4 mm.

Conclusions

This retrospective study showed that sinus floor elevation with PRF alone could be applied in cases of lower RBH. However, it should be carefully performed in cases of RBH < 4 mm before surgery. Key words:Platelet-rich fibrin, dental implant, sinus augmentation, retrospective study.

Preliminary Results of Bone Regeneration in Oromaxillomandibular Surgery Using Synthetic Granular Graft

Traumatic, neoplastic, inflammatory, or infective dental removal promotes a gradual resorption process of bone which leads to a “nonuse” atrophy of the alveolar ridges. Many techniques allows restoring an appropriate bone thickness, but nowadays the attention is focused on the use of natural or synthetic grafts. Numerous studies have been conducted to develop and test new synthetic materials. In this article, the authors report their experience using a synthetic bone substitute in combination with Platelet Rich Fibrin (PRF). This technique was applied in different zones of the maxillomandibular district. The procedure showed a very satisfying bone regeneration without important complications.

Endodontic Management of a Chronic Periapical Abscess in a Maxillary Central Incisor with an Immature Root Apex Using Platelet-Rich Fibrin: A Case Report

Platelet-rich fibrin (PRF) has been used for several treatments in dentistry. The present study reports the clinical and radiographic outcomes of a root canal treatment of a necrotic immature maxillary central incisor using PRF. A 15-year-old female patient presented with a diagnosis of maxillary left central incisor pulp necrosis with open apex and periapical radiolucency and extraoral sinus tract. Two months after a two-visit root canal treatment using calcium hydroxide as a root canal dressing, no clinical symptoms were observed, and the previous sinus tract at the patient's nostril had completely disappeared. In the subsequent visit, the PRF was prepared and delivered into the root canal. The PRF layer was covered with collagen membrane and then sealed with white mineral trioxide aggregate. One year later, the patient remained asymptomatic. Radiological examination using cone beam computed tomography (CBCT) showed that the destructive buccal alveolar bone was completely repaired.

Closure of Oroantral Communication With Plasma-Rich Fibrin Membrane

Oroantral communication (OAC) is the opening between the maxillary sinus and oral cavity. It may cause oroantral fistula or maxillary sinusitis if left untreated. The surgical closure of the OAC within 48 hours was recommended to avoid the complications like sinus infections. The aim of this study is to evaluate the treatment of OACs with plasma-rich fibrin (PRF) which is safe and easy to implement in the OACs.This study was conducted with the patients, who required the treatment of the OAC, which was developed after the posterior maxillary tooth extraction in the Dental and Maxillofacial Department of the Faculty of Dentistry in Adnan Menderes University.Plasma-rich fibrin membranes were inserted in layers into the tooth socket so that they covered the OAC. Then these membranes were fixated with the sutures to the surrounding gingiva. Antibiotic (amoxicillin/clavulanic acid 1000 mg), analgesic (dexketoprofen trometamol and/or paracetamol), and oral rinse (0.2% chlorhexidine digluconate) agents were prescribed to all patients. The patients were examined in the 3rd and 7th days and 2 months after the operation.All patients tolerated PRF perfectly, and the soft tissue recovery was completed without any problem. Full epithelization was observed in the defect area in all patients. The OAC did not relapse in any patient.Plasma-rich fibrin technique is a simple and effective method, which can be used in the treatment of OACs with a diameter of 5 mm or less with a low risk of complications.

Bone alkaline phosphatase and osteocalcin expression of rat's Gingival mesenchymal stem cells cultured in platelet-rich fibrin for bone remodeling (in vitro study)

OBJECTIVE

The aim of this study was to analyze the osteogenic differentiation of rat GMSCs cultured in PRF for bone remodeling.

MATERIALS AND METHODS

GMSCs were isolated from the lower gingival tissue of four healthy, 250 g, 1-month old, male rats (Rattus norvegicus) cut into small fragments, cultured for 2 weeks, and subsequently passaged every 4-5 days. GMSCs isolated in passage 3 were characterized by CD34, CD45, CD44, CD73, CD90, and CD105 using fluorescein isothiocyanate immunocytochemistry (ICC) examination. GMSCs in passage 3-5 cultured in five M24 plates (N = 108; n = 6/group) for 7, 14, and 21 days with three different mediums as follows: Control (-) group: α-Modified Eagle Medium; Control (+) group: High-dose glucose Dulbecco's Modified Eagle's Medium (DMEM-HG) + osteogenic medium; and treatment group: DMEM-HG + osteogenic medium + PRF. GMSCs were osteogenic differentiation cultured in vitro in three different mediums by bone alkaline phosphatase (BALP) and osteocalcin (OSC) marker using ICC monoclonal antibody.

STATISTICAL ANALYSIS USED

The one-way analysis of variance was performed (P < 0.05) based on Shapiro-Wilk and Levene's tests (P > 0.05).

RESULTS

GMSCs were shown to present + CD44, +CD73, +CD90, +CD105 and - CD34, - and CD45 expression as MSCs markers. The treatment group showed the highest BALP expression (16.00 ± 1.732) on day 7, while OSC expression (13.67 ± 2.309) on day 21 showed the statistically significant difference between groups (P < 0.05).

CONCLUSION

GMSCs cultured in PRF demonstrated potential osteogenic differentiation ability capable of accelerating in vitro bone remodeling by enhancing BALP and OSC expression.

Healing capacity of bone marrow mesenchymal stem cells versus platelet-rich fibrin in tibial bone defects of albino rats: an in vivo study

Background: Various techniques for tissue engineering have been introduced to aid the regeneration of defective or lost bone tissue. The aim of this study was to compare the in vivo bone-forming potential of bone marrow mesenchymal stem cells (BM-MSCs) and platelet-rich fibrin (PRF) on induced bone defects in rats' tibiae. Methods: In total, one defect of 3-mm diameter was created in each tibia of 36 Wistar male rats. There were two groups: group A, left tibia bone defects that received PRF; and group B, right tibia bone defects of the same animal that received BM-MSCs loaded on a chitosan scaffold. Subsequently, Scanning electron microscope/energy-dispersive X-ray (SEM/EDX) analyses was performed at 3 and 10 days, and 3 weeks post‑implantation and following euthanasia; (n=12). Results: The EDX analysis performed for each group and time point revealed a significant increase in the mean calcium and phosphorous weight percentage in the BM-MSC-treated group relative to the PRF-treated group at all-time intervals (P < 0.05). Moreover, the mean calcium and phosphorus weight percentage increased as time progressed since the surgical intervention in the PRF-treated and BM-MSCs groups (P < 0.05). Conclusions: In the present study, both BM-MSCs and PRF were capable of healing osseous defects induced in a rat tibial model. Yet, BM-MSCs promoted more adequate healing, with higher mean calcium and phosphorous weight percentages than PRF at all-time points, and showed greater integration into the surrounding tissues than PRF.

Platelet‑rich fibrin exudate promotes the proliferation and osteogenic differentiation of human periodontal ligament cells in vitro

The purpose of the present study was to evaluate the effects of platelet-rich fibrin (PRF) exudate on the proliferation, osteogenic differentiation and mineralization of human periodontal ligament cells (hPDLCs) in vitro. In the present study PRF was obtained with permission, from the peripheral blood of healthy donors and PRF exudates were collected on the 7th day of incubation. hPDLCs were obtained from healthy premolars, cultured by a tissue explant method and identified with anti-vimentin and anti-cytokeratin antibodies. PRF exudates were added to hPDLCs in different concentrations to evaluate cell proliferation and osteogenic differentiation. The proliferation of hPDLCs was measured using a colorimetric assay. Osteogenic differentiation and mineralization were determined by Alizarin red staining, alkaline phosphatase activity (ALP), western blotting and reverse transcription-quantitative polymerase chain reaction. Cell proliferation was enhanced by addition of the PRF exudate, which also promoted the formation of mineralized matrix nodules and upregulated ALP activity and osteoblast-associated levels of osteocalcin, runt-related transcription factor and osterix gene expression. As these stimulatory effects occurred in a dose-dependent manner, it was concluded that high concentrations of the PRF exudate served an essential role in the proliferation, osteogenic differentiation and mineralization of hPDLCs in vitro. The present study demonstrated that PRF exudate enhanced hPDLC proliferation, induced the osteoblastic differentiation of hPDLCs into mineralized tissue-formation cells in vitro, and may therefore provide potential benefits for periodontal tissue engineering; contributing to the primary processes of periodontal tissue regeneration. From the perspective of both economics and biology, PRF has greater clinical benefits than analogous growth factors.

Autologous platelet-rich fibrin: can it secure a better healing?

OBJECTIVE

The aim of this study was to evaluate the efficacy of platelet-rich fibrin (PRF) in the healing of impacted mandibular third molar (M3) extraction sockets.

STUDY DESIGN

This study included 30 patients with bilaterally symmetric impacted M3 (N = 60) requiring transalveolar extraction. All patients were assigned numbers randomly; left-sided M3 patients with odd numbers and right-sided patients with even numbers were categorized into group A (test group), and the other side of the mouth was classified as "group B" (control group). Group A M3 extraction sockets received PRF, whereas group B sockets were closed without PRF. Patients were evaluated for pain and swelling on postoperative days 1, 3, 7, and 14. Bone healing was compared on postoperative weeks 8 and 16. Analysis of variance (ANOVA) and Tukey's multiple comparison tests were applied for statistical analysis.

RESULTS

A total of 30 patients, ages 18 to 40 years, participated in this study. The overall postoperative pain score (visual analogue scale [VAS]) and facial swelling percentages were lower for group A compared with group B (P < .05). Early bone healing was also evident on postoperative radiographs obtained at weeks 8 and 16 in group A (P < .001).

CONCLUSIONS

The use of autologous PRF aids in earlier and better wound healing in a controlled manner.

Autologous liquid platelet rich fibrin: A novel drug delivery system

There is currently widespread interest within the biomaterial field to locally deliver biomolecules for bone and cartilage regeneration. Substantial work to date has focused on the potential role of these biomolecules during the healing process, and the carrier system utilized is a key factor in their effectiveness. Platelet rich fibrin (PRF) is a naturally derived fibrin scaffold that is easily obtained from peripheral blood following centrifugation. Slower centrifugation speeds have led to the commercialization of a liquid formulation (liquid-PRF) resulting in an upper plasma layer composed of liquid fibrinogen/thrombin prior to clot formation that remains in its liquid phase for approximately 15 min until injected into bodily tissues. Herein, we introduce the use of liquid PRF as an advanced local delivery system for small and large biomolecules. Potential target molecules including large (growth factors/cytokines and morphogenetic/angiogenic factors), as well as small (antibiotics, peptides, gene therapy and anti-osteoporotic) molecules are considered potential candidates for enhanced bone/cartilage tissue regeneration. Furthermore, liquid-PRF is introduced as a potential carrier system for various cell types and nano-sized particles that are capable of limiting/by-passing the immune system and minimizing potential foreign body reactions within host tissues following injection.

STATEMENT OF SIGNIFICANCE

There is currently widespread interest within the biomaterial field to locally deliver biomolecules for bone and cartilage regeneration. This review article focuses on the use of a liquid version of platelet rich fibrin (PRF) composed of liquid fibrinogen/thrombin as a drug delivery system. Herein, we introduce the use of liquid PRF as an advanced local delivery system for small and large biomolecules including growth factors, cytokines and morphogenetic/angiogenic factors, as well as antibiotics, peptides, gene therapy and anti-osteoporotic molecules as potential candidates for enhanced bone/cartilage tissue regeneration.

Relationships of Age and Sex with Cytokine Content and Distribution in Human Platelet Fibrin Gels

We aimed to determine relationships between age and sex with cytokine content and distribution in human platelet-rich fibrin (PRF) gel. Rabbit PRF was harvested from whole blood (n = 6). Human PRF was collected from 36 healthy volunteers (1:1 men:women) without systemic diseases and not current undergoing medical treatment. Histological analysis and optical microscopy were used to assess the three-dimensional structure of the PRF network. Enzyme-linked immunosorbent assays, quantification of adenosine triphosphate, and bioluminescence imaging of PRF sections were used to assess cytokine and entrapped platelet distribution. Three-dimensional structures of fibrin networks revealed concentration gradients of the platelet-derived growth factor beta beta homodimer and the transforming growth factor-beta 1. Histological analysis of PRF sections (from the red blood cell end to the plasma end of a clot) showed a gradual increase in average porosity, most prominently in PRF clots from young and middle-aged men and women, and a decrease in compactness along the longitudinal axis of the PRF gel. The end of the PRF gel closest to the red blood cell layer is the essence of the PRF clot, and the ability to generate platelets depends on sex and age in humans.

In vitro evaluation of decontamination effects on mechanical properties of fibrin membrane

Background: Tissue engineering has been investigated as a potential method for healing traumatized tissues. Biomaterials are material devices or implants used to repair or replace native body tissues and organs. The present study was conducted to evaluate the effects of decontamination methods on biological/mechanical properties and degradation/adhesion test of the platelet-rich fibrin (PRF) membranes to compare these properties with intact membranes as a biological biomaterial.

Methods: The in vitro degradation tests were conducted by placing the equal sizes of (i) intact PRF membrane, (ii) PRF membrane sterilized by autoclave (iii), ultraviolet (UV), and (iiii) gamma irradiation in phosphate buffer solution on a shaker. The degradation profiles were expressed. Adhesion test was performed by counting adhered mouse fibroblast and sterilized fibrin membrane was compared to normal fibrin membrane by different sterilization methods.

Results: The preliminary findings of sterilized PRF membranes showed that UV exposure (p<0.05) and autoclaved fibrin membranes (p<0.01) have significantly lower degradability compared to normal fibrin membranes. Gamma irradiation is similar to normal membrane in degradability. Cell adherence in all groups of fibrin membrane was significantly lower than the group without membrane, but there was no significant difference between intact and sterilized groups of fibrin membranes.

Conclusion: Sterilization of fibrin membrane with different protocols does not have any adverse effects on cell adhesion; however, cell adherence is naturally very weak even in normal membranes. Also, it seems that ultraviolet ray polymerizes fibrin filaments and merges them to each other and increases the ability of fibrin membrane against degradation. Autoclaved fibrin membrane content proteins are denatured because of pressure and heat and show an increase in hardness and stability against degradation.

To assess the efficacy of socket plug technique using platelet rich fibrin with or without the use of bone substitute in alveolar ridge preservation: a prospective randomised controlled study

AIM

The purpose of this study is to evaluate the efficacy of Platelet Rich Fibrin (PRF) as a socket plug with or without use of Plaster of Paris (POP) as bone substitute to preserve the alveolar ridge post-extraction.

MATERIAL AND METHODS

A prospective randomised single blind controlled study, was conducted for 18 months from November 2014 to May 2016 on 48 patients requiring extraction. All teeth were extracted atraumatically using periotomes and luxators without raising mucoperiosteal flap. Sockets were randomly allotted to groups A, B and C. Group A sockets were chosen as control, where figure of eight suture was placed. In group B sockets, PRF obtained by centrifugation was used as a socket plug and stabilised with figure of eight suture. Group C sockets were filled with POP and then covered with PRF. The socket was then closed with a figure of eight suture. Patients were informed of need for 6 months follow-up.

RESULTS

Ninety sockets in 48 patients were subjected to our study. We found that results in the sockets where we have grafted POP showed better ridge preservation and post-operative comfort even though the difference in ridge resorption between the three groups was not statistically significant. Powered by Editorial Manager® and ProduXion Manager® from the Aries Systems Corporation.

CONCLUSION

Atraumatic extraction may minimise the post-operative pain and discomfort to patient as well as the post-extraction alveolar height and width changes. The use of PRF and/or bone substitute even though clinically contributes to better post-operative healing and minimal loss of alveolar width and height, the values were not statistically significant.

The use of platelet-rich fibrin with platelet-rich plasma support meniscal repair surgery

Introduction

Platelet-rich fibrin (PRF) is the only autologous blood product that releases growth factors and has scaffolding properties. We hypothesized that the use of PRF and Platelet-rich plasma (PRP) would improve operative results, including the recovery of function and repaired meniscus.

Materials and Methods

Seventeen patients underwent arthroscopic meniscus repair with PRF and PRP (PRF group) using our novel device for the injection of the PRF into the joint. Another five patients as a control group underwent meniscal repair without PRF and PRP (non-PRF group). The groups were compared in terms of clinical results (Tegner Activity Level Scale, Lysholm Knee Scoring Scale, and International Knee Documentation Committee [IKDC] scores) and changes in magnetic resonance imaging (MRI) findings before surgery and 6 months after surgery.

Results

The Lysholm and IKDC scores improved in all patients postoperatively. However, there was no significant differencies in the postoperative score between the PRF group and the non-PRF group. Follow-up MRI findings did not clearly show improvements.

Conclusions

PRF and PRP are autologous, safe, and cost-effective sources of growth factors. Therefore, we propose a new application of PRF and PRP for autologous transplantation in meniscus repair surgery.

A Comparative Evaluation of Concentrated Growth Factor and Platelet-rich Fibrin on the Proliferation, Migration, and Differentiation of Human Stem Cells of the Apical Papilla

INTRODUCTION

Concentrated growth factor (CGF) is considered to be a natural biomaterial that is better than platelet-rich fibrin (PRF) in bone regeneration, but there is little information acquired in regenerative endodontics. Therefore, the purpose of this study was to evaluate their effects on the proliferation, migration, and differentiation of human stem cells of the apical papilla (SCAPs).

METHODS

CGF- and PRF-conditioned medium were prepared using the freeze-dried method. SCAPs were isolated and identified. The proliferative potential of SCAPs was investigated using the Cell Counting Kit-8 (KeyGen Biotech, Nanjing, China). The migration capacity was analyzed using transwell assays, and the mineralization ability was determined by alizarin red S staining. The expression levels of alkaline phosphatase, bone sialoprotein, dentin matrix protein 1, and dentin sialophosphoprotein were determined by quantitative polymerase chain reaction.

RESULTS

The cultured cells exhibited mesenchymal stem cell characteristics. The growth rate and migratory cell numbers of the CGF and PRF groups were significantly greater than those of the control group. The mineralized areas in the CGF and PRF groups were significantly larger than those in the control group after incubation for 7 days and 14 days. The expression levels of osteogenic/odontoblast-related genes were reduced on day 7, but they were dramatically enhanced on day 14, and the related gene expression levels in the PRF group were higher than those in the CGF group.

CONCLUSIONS

Both CGF and PRF can promote the proliferation, migration, and differentiation of SCAPs. CGF may be a promising alternative in regenerative endodontics.

Clinical Application of Platelet-Rich Fibrin in Plastic and Reconstructive Surgery: A Systematic Review

BACKGROUND

Platelet-rich fibrin (PRF) has been applied in the clinical field for more than a decade, but largely in oral surgery and implant dentistry. Its utilization in plastic and reconstructive surgery is limited and lacking a comprehensive review. Hence, this article focuses on the various clinical applications of PRF pertaining to the plastic and reconstructive field through a systematic review.

METHODS

In this review, articles describing the clinical application of PRF in plastic and reconstructive surgery were screened using predetermined inclusion and exclusion criteria. The articles were summarized and divided into groups based on the utilization of PRF. The effects and complications of PRF were analyzed and concluded.

RESULTS

Among the 634 articles searched, 7 articles describing 151 cases are eligible. PRF was applied on 116 (76.8%) wounds to facilitate tissue healing, and the complete wound closure rate was 91.4% (106/116). Otherwise, PRF was applied in 10 (6.6%) cases of zygomaticomaxillary fracture to reconstruct orbital floor defects and in 25 (16.6%) cases of facial autologous fat grafts to increase the fat retention rate successfully. There is no report of PRF-related complications.

CONCLUSIONS

PRF could facilitate wound healing, including the healing of soft tissues and bony tissues, and facilitate fat survival rate. Further studies are needed to test the mechanism of PRF and expand its scope of application in plastic and reconstructive surgery.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Enhancement of post-orthodontic tooth stability by carbonated hydroxyapatite-incorporated advanced platelet-rich fibrin in rabbits

OBJECTIVE

To evaluate the effect of carbonated hydroxyapatite-incorporated advanced platelet-rich fibrin on relapse and bone remodelling in rabbits.

MATERIALS AND METHODS

Forty-five rabbits were divided into 3 groups (n = 15): a control group, carbonated hydroxyapatite (CHA) and carbonated hydroxyapatite-incorporated advanced platelet-rich fibrin (CHA-aPRF) group. The lower incisors were subjected to an orthodontic force of 50 cN. During the retention period, CHA and CHA-aPRF hydrogel were gently injected in the mesial gingival sulcus every 7 days. Next, the appliances were debonded to allow relapse. At 5 subsequent time points (0, 3, 7, 14 and 21 days after debonding), the distance between the mesial tips of rabbits incisors was measured using a digital calliper, osteoblast quantity was evaluated using haematoxylin-eosin staining and osteoclast activity was examined using tartrate-resistant acid phosphatase (TRAP) staining.

RESULTS

The relapse rate of CHA-aPRF group was lower than that of the other groups, and the relapse distances were significantly lower on days 14 and 21 (P < .05). Histological analysis revealed that the number of osteoblasts was significantly higher and that the osteoclast activity was significantly lower in the CHA-aPRF group compared with the other groups (P < .05).

CONCLUSIONS

Intrasulcular injection of hydrogel CHA incorporated aPRF can locally reduce orthodontic relapse in rabbits.

Immediate mandibular reconstruction via patient-specific titanium mesh tray using electron beam melting/CAD/rapid prototyping techniques: One-year follow-up

BACKGROUND

Immediate mandibular reconstruction was performed using a patient-specific titanium mesh tray fabricated by electron beam melting (EBM) /rapid prototyping techniques.

METHODS

Patient-specific titanium trays were virtually designed and fabricated using EBM technology/rapid prototyping for patients requiring mandibular resection and immediate reconstruction using an iliac crest bone graft. Dental implants were placed in the grafted sites and the patients received prosthetic rehabilitation with a follow-up of one year. Clinical data, postoperative bone formation and complications were evaluated.

RESULTS

A symmetric appearance of facial contours was achieved. The titanium tray incorporated the particulate iliac crest bone graft that provided significant bone formation (mean 18.97 ± 1.45 mm) and predictable results. Stability of the dental implants was achieved.

CONCLUSION

The patient-specific titanium meshes and immediate particulate autogenous bone graft showed satisfactory clinical and surgical results in improving patients' quality of life and decreasing the overall treatment time with adequate functional rehabilitation.

Effects of Growth Factors From Platelet-Rich Fibrin on the Bone Regeneration

Platelet-rich fibrin (PRF) has simple manufacturing process without risk of immunologic rejection or infection by additional materials. This study was designed to investigate the effects of platelet-derived growth factors and transforming growth factors-β in PRF on the proliferation and differentiation of osteoblasts. The authors analyzed platelet-derived growth factors and transforming growth factors-β in normal human serum (NHS) and PRF by enzyme-linked immunosorbent assay quantitatively and those in PRF group were significantly increased when compared with NHS. After harvesting osteoblasts from iliac bone, the authors added 10% fetal bovine serum, 10% NHS, and 3% PRF to osteoblasts, respectively and incubated for 24, 48, 72 hours. For analysis of osteoblast proliferation and differentiation, the authors measured DNA synthesis by [3H]-thymidine isotope activity, protein synthesis by sulforhoamine B assay and those were increased according to elapsed time in all groups, but they were significantly increased in 3% PRF. The authors measured alkaline phosphatase activity of osteoblasts, it was increased according to elapsed to time in all groups, but significantly increased in 72 hours. In conclusion, application of PRF to bone defect sites may have an enhanced effect of bone regeneration with low risk of complications, and relatively simple manufacturing process.

Clinical effect of platelet-rich fibrin on the preservation of the alveolar ridge following tooth extraction

The aim of the present study was to evaluate the clinical efficacy of platelet-rich fibrin (PRF) in preserving the alveolar ridge following human tooth extraction. A total of 28 patients were divided into two groups: The experimental and control groups (n=14 each). Following tooth extraction, the experimental group was implanted with PRF membrane, whereas the control group was not. The gingival healing effect was assessed at 7 days, 1 and 3 months later. Cone-beam computed tomography was performed immediately and at 3 months following tooth extraction. The changes in alveolar ridge height, width, and bone mineral density were compared between the two groups. The alveolar bone was removed using the ring drill during the implant surgery at 3 months following tooth extraction. Histomorphometric evaluation was performed to compare new bone formation between groups. The patients in the experimental group reportedly felt better compared with the patients in the control group. The healing of gingival tissue was better in the experimental group than in the control group. A significantly greater novel bone area was observed in the PRF group compared with the control group (P<0.01). However, no statistically significant differences were observed in the mean value of buccal alveolar ridge height, lingual/palatal alveolar ridge height and alveolar ridge width between the two groups. These results suggested that PRF was advantageous in human alveolar ridge preservation with ease of use and simple handling. Histological analysis of novel bone formation confirmed that PRF increased the quality of the novel bone and enhanced the rate of bone formation, despite the effect of PRF was not significant to reduce alveolar bone resorption in the extraction socket alone.

Enhancing effects of basic fibroblast growth factor and fibronectin on osteoblast adhesion to bone scaffolds for bone tissue engineering through extracellular matrix-integrin pathway

The present study aimed to investigate the effects of basic fibroblast growth factor (bFGF) and fibronectin (FN) on adhesion of osteoblasts seeded into bio-derived bone scaffolds. Rat calvarial osteoblasts were separated and their osteogenic phenotypes were determined by staining for alkaline phosphatase as well as alizarin red staining. The bio-derived bone scaffolds were prepared from the metaphysis of porcine femur and their physicochemical properties were assessed by scanning electron microscopy (SEM) and X-ray diffraction analysis. An MTT assay was used to detect the effects of bFGF and FN on osteoblast adhesion or proliferation on cell/scaffold constructs through blocking the extracellular matrix FN-integrin pathway by the Gly-Arg-Gly-Asp-Ser (GRGDS) peptide. Western blot analysis was used to measure the β1 integrin levels. Based on the adhesion of osteoblasts stimulated by various concentrations of bFGF (0.1, 1, 10 and 100 ng/ml) on bio-derived bone scaffolds modified by various concentrations of FN (0.1, 1, 10 and 100 µg/ml), the cell/scaffold constructs were divided into four groups: i) Control, non-stimulated and non-modified group; ii) 10 µg/ml FN-modified group; iii) 100 ng/ml bFGF-stimulated group; iv) 10 µg/ml FN + 100 ng/ml bFGF group. Cell proliferation curves acquired by MTT assay and micrographs obtained by SEM showed that the combination of bFGF and FN significantly improved cell adhesion, particularly in the 10 µg/ml FN + 100 ng/ml bFGF group vs. the other groups, and the effect on cell adhesion was inhibited by 1 mmol/l GRGDS peptide through the FN-integrin pathway. Western blot results showed that the combination of bFGF and FN significantly enhanced β1 integrin expression levels. These results suggested that osteoblasts stimulated by 100 ng/ml bFGF and bio-derived bone materials modified by 10 µg/ml FN should be combined to be applied in the bone tissue engineering.

Treatment of endo-periodontal lesion using leukocyte-platelet-rich fibrin. A case report

Case Description:

The main objective of this paper was to report the clinical effectiveness of leukocyte- platelet- rich fibrin (L-PRF) in the treatment of a combined endo-periodontal lesion of an upper first premolar.

Clinical Findings:

The tooth had a profound abfraction on the vestibular aspect and presented no mobility but revealed a deep pocket measuring of 11 mm on the mesial vestibular aspect and 14 mm on the mesial palatine aspect. The three dimensional image analysis showed total bone loss in the mesial aspect and an extensively bone loss of the vestibular aspect of the vestibular root.

Treatment and Outcome:

Endodontic treatment was performed and periodontal access surgery (surgical periodontal therapy) was done with the application of autologous L-PRF. Three month and 6 months after surgery, the cone beam computed tomography (CBCT) exams showed no bone regeneration in any aspect of the tooth. However, periodontal examination showed a significative improvement in the deepness of surcus. The mesial vestibular aspect had a deep pocket of 3 mm and 5 mm on the mesial palatine aspect showing a reduction in deepness of 8 mm and 9 mm, respectively.

Clinical Relevance:

The actual treatment for teeth with bad prognosis is the extraction and replacement with implants. Even though implants are capable of restore function and aesthetic, the abuse of this approach have led to the loss of teeth that could be successfully treated with a less invasive technique. The prognosis of teeth with endoperiodontal lesion is poor but could be enhanced with regenerative therapies. Until now there are no clinical trials and just four case report about the treatment of these teeth with platelet rich fibrin.

Comparison of the Effects of Osteochondral Autograft Transplantation With Platelet-Rich Plasma or Platelet-Rich Fibrin on Osteochondral Defects in a Rabbit Model

BACKGROUND

Although osteochondral autograft transplantation (OAT) provides satisfactory outcomes for osteochondral defects, for large defects OAT is often inadequate because of graft availability. Osteochondral allograft transplantation is an alternative treatment for large defects, but this approach is limited by graft storage constraints and carries disease transmission risks. Platelet-rich fibrin (PRF) is a second-generation platelet concentrate, and its positive effect on articular cartilage has been reported. However, the effect of PRF with OAT of osteochondral defects is unknown.

PURPOSE

To compare the effects of OAT with platelet-rich plasma (PRP) and PRF on osteochondral defects in a rabbit model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Forty-two juvenile rabbits were divided into control, PRP, and PRF groups. In the control and PRP groups, a cylindrical osteochondral defect (5 mm in diameter and 2 mm in depth) was created on the patellar groove, and an osteochondral graft (3.5 mm in diameter and 5 mm in length) harvested from the contralateral side was inserted into the distal portion of the defect. After wound closure, either normal saline or PRP was injected in the knee. In the PRF group, a PRF clot was placed in the defect before grafting. The surgical site was macroscopically and histologically assessed after 3 and 12 weeks.

RESULTS

At 3 weeks, the PRF group (n = 8) was macroscopically healed compared with the other 2 groups (control, n = 7; PRP, n = 6) ( P < .005). Histologically, osteochondral graft cartilage of the PRF group had normal cellularity and higher amounts of safranin O staining relative to the other 2 groups ( P < .005). At 12 weeks, all 3 groups (n = 8 per group) were macroscopically healed with normal or nearly normal cartilage, and osteochondral graft cartilage was histologically hyaline cartilage. In contrast, the PRF group healed with hyaline-like cartilage at nongrafted defects, whereas the other 2 groups healed with fibrocartilage ( P < .001).

CONCLUSION

OAT with PRF maintained hyaline cartilage, and the nongrafted defect healed with hyaline-like cartilage.

CLINICAL RELEVANCE

PRF has the potential to improve clinical outcomes of OAT used to treat osteochondral lesions.

Injectable Mussel-Inspired Immobilization of Platelet-Rich Plasma on Microspheres Bridging Adipose Micro-Tissues to Improve Autologous Fat Transplantation by Controlling Release of PDGF and VEGF, Angiogenesis, Stem Cell Migration

Platelets-rich plasma (PRP) can produce growth factors (GFs) to improve angiogenesis. However, direct injection of PRP does not lead to highly localized GFs. The current study employs a mussel-inspired polydopamine to immobilize PRP on gelatin microspheres (GMs) with the purpose of bridging adipose micro-tissues to help implanted fat survive (GM-pDA-PRP). Enhanced PRP adhesion leads to a prolonged and localized production of GFs, which is verified by platelet counting and by ELISA of vascular endothelial growth factors (VEGFs) and of platelet derived growth factors (PDGFs). The GM-pDA-PRP "hatches" a microenvironment for the proliferation of adipose-derived stem cells. After the adipose micro-tissue has bridged with GM-pDA-PRP after 16 weeks, triple-fluorescence staining reveals that the mature adipocytes, blood vessels, and capillaries are arranged like in normal adipose tissue. The survival fat increases significantly compared to that in control, PRP, and GM-PRP groups (84.8 ± 11.4% versus 47.8 ± 8.9%, 56.9 ± 9.7%, and 60.2 ± 10.5%, respectively). Both histological assessments and CD31 immunofluorescence indicate that the improvement of angiogenesis in GM-pDA-PRP is higher than in the fat graft group (6.4-fold in quantitative CD31 positive cells). The CD34 positive cells in the GM-pDA-PRP group are around 3.5-fold the amount in the fat graft group, which suggests that more stem cells migrate to the implant area. Cell proliferation staining shows that the number of Ki67 positive cells is around five times as high as that in the fat graft group.

An Innovative Regenerative Endodontic Procedure Using Leukocyte and Platelet-rich Fibrin Associated with Apical Surgery: A Case Report

Regenerative endodontic procedures (REPs) associated with apical surgery could represent an alternative treatment strategy for patients whose teeth present incomplete root formation and extensive apical lesions. Leukocyte platelet-rich fibrin (L-PRF) has potential benefits in REPs; it could promote apical root formation and optimal bone healing. The aim of this case report was to describe innovative regenerative endodontic therapy using L-PRF in the root canal and an extensive apical lesion in an immature tooth with dens invaginatus and asymptomatic apical periodontitis. A healthy 20-year-old woman was referred to the dental clinic of the Universidad de Los Andes, Santiago, Chile, for endodontic treatment in tooth # 22 with incomplete root development and an extensive apical lesion. The diagnosis was asymptomatic apical periodontitis associated with dens invaginatus type II. The patient was treated with an innovative approach using L-PRF in REPs associated with apical surgery. Follow-ups were performed at 6 months and 1 year later. They included periapical radiographs, cone-beam computed tomographic imaging, sensitivity, and vitality tests. The clinical evaluations performed at 6 months and 1 year revealed an absence of symptoms. The radiographic evaluations showed that the apical lesion was resolved. The cone-beam images indicated that the root length increased and the walls had thickened. The sensitivity tests were positive, and the laser Doppler flowmetry showed positive blood flow after 1 year. The success of the results in this case report indicate that L-PRF can be used as a complement in apical surgery and REPs and could provide an innovative alternative treatment strategy for complex clinical cases like these.

Regenerative Potential of Platelet Rich Fibrin (PRF) for Curing Intrabony Periodontal Defects: A Systematic Review of Clinical Studies

Platelet-rich fibrin (PRF) has been used in regenerative medicine and dentistry. Recently, its use has been advocated for regenerative periodontics and wound healing. The randomized control trials have assessed the regenerative efficacy of the PRF for restoring intrabony periodontal defects. The objectives are to critically analyze and appraise the currently available literature, focusing on the use of PRF in regenerating periodontal bone defects. An electronic search was conducted (PubMed/MEDLINE, Google Scholar, ISI-WOS). Various combinations of following keywords were used: 'platelet-rich fibrin', 'intrabony', 'periodontal', 'bone defect' and 'guided tissue regeneration'. A secondary search was conducted by analyzing the reference lists of the articles obtained in initial search. The final search resulted in 13 randomized controlled trials being included. In majority of studies, PRF resulted in better clinical/radiographic outcomes than open flap debridement and augmented therapeutic effects of bone grafts. The combination of bovine bone substitutes and PRF resulted in better performance compared to alone. Similarly better outcomes were observed while using PRF in combination with nanohydroxyapatite, metformin and demineralized freeze-dried bone allograft. It can be concluded that PRF produces better outcomes than open flap debridement alone and augments the regenerative effects of bone substitutes.

Obtention of injectable platelets rich-fibrin (i-PRF) and its polymerization with bone graft: technical note

The use of autologous platelet concentrates, represent a promising and innovator tools in the medicine and dentistry today. The goal is to accelerate hard and soft tissue healing. Among them, the platelet-rich plasma (PRP) is the main alternative for use in liquid form (injectable). These injectable form of platelet concentrates are often used in regenerative procedures and demonstrate good results. The aim of this study is to present an alternative to these platelet concentrates using the platelet-rich fibrin in liquid form (injectable) and its use with particulated bone graft materials in the polymerized form.

A New Method to Develop Human Dental Pulp Cells and Platelet-rich Fibrin Complex

INTRODUCTION

Platelet-rich fibrin (PRF) has been used as a scaffold material in various tissue regeneration studies. In the previous methods to combine seed cells with PRF, the structure of PRF was damaged, and the manipulation time in vitro was also increased. The objective of this in vitro study was to explore an appropriate method to develop a PRF-human dental pulp cell (hDPC) complex to maintain PRF structure integrity and to find out the most efficient part of PRF.

METHODS

The PRF-hDPC complex was developed at 3 different time points during PRF preparation: (1) the before centrifugation (BC) group, the hDPC suspension was added to the venous blood before blood centrifugation; (2) the immediately after centrifugation (IAC) group, the hDPC suspension was added immediately after blood centrifugation; (3) the after centrifugation (AC) group, the hDPC suspension was added 10 minutes after blood centrifugation; and (4) the control group, PRF without hDPC suspension. The prepared PRF-hDPC complexes were cultured for 7 days. The samples were fixed for histologic, immunohistochemistry, and scanning electron microscopic evaluation. Real-time polymerase chain reaction was performed to evaluate messenger RNA expression of alkaline phosphatase and dentin sialophosphoprotein. Enzyme-linked immunosorbent assay quantification for growth factors was performed within the different parts of the PRF.

RESULTS

Histologic, immunohistochemistry, and scanning electron microscopic results revealed that hDPCs were only found in the BC group and exhibited favorable proliferation. Real-time polymerase chain reaction revealed that alkaline phosphatase and dentin sialophosphoprotein expression increased in the cultured PRF-hDPC complex. The lower part of the PRF released the maximum quantity of growth factors.

CONCLUSIONS

Our new method to develop a PRF-hDPCs complex maintained PRF structure integrity. The hDPCs were distributed in the buffy coat, which might be the most efficient part of PRF.

Guided bone regeneration: materials and biological mechanisms revisited

Guided bone regeneration (GBR) is commonly used in combination with the installment of titanium implants. The application of a membrane to exclude non‐osteogenic tissues from interfering with bone regeneration is a key principle of GBR. Membrane materials possess a number of properties which are amenable to modification. A large number of membranes have been introduced for experimental and clinical verification. This prompts the need for an update on membrane properties and the biological outcomes, as well as a critical assessment of the biological mechanisms governing bone regeneration in defects covered by membranes. The relevant literature for this narrative review was assessed after a MEDLINE/PubMed database search. Experimental data suggest that different modifications of the physicochemical and mechanical properties of membranes may promote bone regeneration. Nevertheless, the precise role of membrane porosities for the barrier function of GBR membranes still awaits elucidation. Novel experimental findings also suggest an active role of the membrane compartment per se in promoting the regenerative processes in the underlying defect during GBR, instead of being purely a passive barrier. The optimization of membrane materials by systematically addressing both the barrier and the bioactive properties is an important strategy in this field of research.

Platelet-Rich Fibrin in Regeneration of Intrabony Defects: A Randomized Controlled Trial

BACKGROUND

Platelet-rich fibrin (PRF) is an autologous non-transfusional hemo-component with a high concentration of platelets. It incorporates leukocytes, platelets, and growth factors within the dense fibrin matrix and can be used as healing biomaterial. This study assesses the adjunctive use of PRF in regenerative management of intrabony defects in comparison with open flap debridement (OFD).

METHODS

Twenty-six bilateral defects (13 per group) in 13 patients were randomized as either PRF (test group) or OFD alone (control group) sites. Probing depth (PD), clinical attachment level (CAL), and bone PD were recorded. Reduction in defect depth and percentage of bone fill was assessed radiographically. Primary outcomes assessed were changes in PD, CAL, and percentage of bone fill, and they were assessed at 6, 9, and 12 months. Secondary outcome was assessment of wound healing using a wound healing index (WHI).

RESULTS

The PRF group showed significant improvement in clinical parameters compared with the control group at 6, 9, and 12 months. The PRF group showed a bone fill of 45.18% ± 7.57%, which was statistically significant compared with 21.6% ± 9.3% seen in the control group at the end of the study period. The PRF group also showed significant soft tissue healing and reduction in PD. WHI also showed significant advantages for the PRF group.

CONCLUSION

The adjunctive use of PRF to conventional OFD may be potentially used in the treatment of intrabony defects.

Influence of platelet rich fibrin on post-extraction socket healing: A clinical and radiographic study

Aim

The aim of this study was to evaluate clinically and radiographically, extraction socket healing using autologous platelet rich fibrin (PRF).

Materials and methods

Twenty-four subjects needing single tooth simple extractions were selected. Twenty-four extraction sockets were divided into test group (PRF, n = 12) and control group (blood clot, n = 12). PRF was prepared with blood drawn from individuals after extraction using standard technique. PRF was placed in test group sockets followed by pressure application and figure 8 sutures. Sockets in control group were allowed to heal in the presence of blood clot and received a figure 8 suture. Ridge width was assessed using cast analysis with the help of acrylic stent and a pair of calipers. Radiographic analysis of socket surface area was performed using computer graphic software program. The clinical follow up assessments were performed at 1, 4 and 8 weeks. Collected data was assessed using ANOVA and multiple comparisons test.

Results

Subjects were aged between 25 and 50 (mean 37.8) years, including 15 females. The mean horizontal ridge width for sockets in the test group were 11.70 ± 2.37 mm, 11.33 ± 2.30 mm and 10.97 ± 2.33 mm at 1, 4 and 8 weeks respectively. Ridge width proportions were significantly higher among test group as compared to control group between baseline to 4 and 8 weeks respectively. The mean radiographic bone fill (RBF) percentage in the test group, was 74.05 ± 1.66%, 81.54 ± 3.33% and 88.81 ± 1.53% at 1, 4 and 8 weeks respectively. The mean RBF was significantly higher in the test group than control group at all time intervals.

Conclusion

The study outcomes demonstrate that the use of PRF accelerate socket wound healing after tooth extraction as noticed by increased bone fill and reduced alveolar bone width resorption using clinical and radiographic methods.

Combination of hydroxyapatite, platelet rich fibrin and amnion membrane as a novel therapeutic option in regenerative periapical endodontic surgery: Case series

•

Our article was an attempt to focus on combined benefits of Bio-Gen mix^®, PRF and amnion membrane to provide a viable regenerative option in periapical surgery.

•

To the best of our knowledge, there has been no evidence related to the application of a human placental membrane in periapical surgery. Our presented case reports provide an insight into this novel therapeutic option.

•

The presented case reports confirm that the amnion membrane combined with bone graft and PRF have enhanced the healing outcomes and provided endodontists a sustainable tool while performing surgeries in the esthetic zone.

Introduction

Periapical surgery is the last resort in the arsenal of an endodontist to effectively deal with periapical lesions that result from necrosis of the pulp. Bone grafts, growth factors and membranes form an array of regenerative materials that influence the healing outcome of periapical surgery.

Presentation of case

The main purpose of the two cases reported here was to assess the potential benefits of a combination of bone graft, platelet-rich fibrin (PRF) and amnion membrane in terms of reduced post-operative discomfort, radiographic evidence of accelerated periapical bone healing and present a novel therapeutic option in the management of large periapical lesions. Two cases of radicular cysts were treated through a combined regenerative approachof Bio-Gen mix^®, PRF and amnion membrane. The patients were assessed for discomfort immediate post-operatively and after a week. The patients were recalled every month for the next 6 months for radiographic assessment of the periapical healing.

Discussion

Literature is replete with articles that have substantiated the role of demineralized bone matrix comprising a mixture of cancellous and cortical bone graft particles in enhancing regeneration. To the best of our knowledge, there has been no evidence related to the application of a human placental membrane in periapical surgery. Hence, the rationale of using a combined approach of Bio-Gen mix^®, PRF and amnion membrane was to combine the individual advantages of these materials to enhance clinical and radiographic healing outcomes. Our present case reports provide an insight into this novel therapeutic option.

Conclusion

The results of this case seriessubstantiatesthe credibility of using a combination ofamnion membrane with a bone graft and PRF to enhance radiographic healing outcome with decreased post-operative discomfort and present a viable regenerative treatment modality in periapical surgery.