Advanced platelet-rich fibrin: a new concept for cell-based tissue engineering by means of inflammatory cells

Effect of advanced and injectable platelet-rich fibrins against Aggregatibacter actinomycetemcomitans in subjects with or without periodontal diseases

Background/purpose: Data for comparing effects of advanced platelet-rich fibrin (A-PRF+) and injectable platelet-rich fibrin (i-PRF) against Aggregatibacter actinomycetemcomitans (Aa) in subjects with differently periodontal conditions are scarce. This study aimed to compare the antimicrobial capacity of A-PRF+ and i-PRF obtained from subjects with or without periodontal diseases against the pathogenic bacteria Aa.

Materials and methods

The number of red blood cells, platelets, and white blood cells on the blood samples of 60 individuals, including healthy subjects (n = 20), patients with gingivitis (n = 20), and patients with periodontitis (n = 20), were analyzed before preparing A-PRF+ and i-PRF. In addition, the in vitro antibacterial effect of the two platelet concentrates was evaluated by using the agar diffusion test and a minimum inhibitory concentration (MIC) experiment.

Results

I-PRF exhibited a significantly better antibacterial effect than A-PRF+ within the gingivitis and periodontitis groups, with a more expansive zone of inhibition and a lower MIC. Among the studied groups, the A-PRF+ and i-PRF collected from the periodontitis group inhibited Aa significantly more compared with the gingivitis and healthy groups.

Conclusion

Although both A-PRF+ and i-PRF exhibited an antibacterial effect against Aa through the zone of inhibition and MIC tests, in the gingivitis and periodontitis groups, i-PRF exhibited better antibacterial activity than A-PRF+, and PRF products from the periodontitis group had greater effects against Aa than PRF products from the two other groups.

Evaluation of postoperative pain and healing following regenerative endodontics using platelet-rich plasma versus conventional endodontic treatment in necrotic mature mandibular molars with chronic periapical periodontitis. A randomized clinical trial

AIM

To evaluate the post-operative pain and the healing of necrotic mature permanent mandibular molar teeth with peri-apical periodontitis after conventional endodontic treatment versus after platelet-rich plasma (PRP) revascularization.

METHODOLOGY

The protocol of this randomized clinical trial was registered at www.

CLINICALTRIALS

gov with identification number NCT03350841. Twenty-eight patients were included in the study after confirming the diagnosis clinically and radiographically. In the first visit, mandibular molar teeth of both groups were mechanically prepared. Double antibiotic paste was prepared and injected then the cavity that was sealed with glass ionomer. At the second visit, the patients were randomized either to control group where standard endodontic treatment was completed by lateral condensation technique or assigned to intervention group where PRP revascularization technique. The degree of spontaneous pain was assessed using numerical rating scale (NRS) pre-operatively, then post-operatively after 6, 12 h and daily for 5 days. Patients were given a placebo to be administrated in case of pain. An analgesic (ibuprofen 400mg) was prescribed in case of persistent pain. Clinical and radiographic healing was assessed after 6 and 12 months. All demographic, baseline and outcome data were collected and statistically analysed.

RESULTS

Regarding the post revascularization/obturation pain, there was no statistically significant difference between severity of pain in the two groups at all time intervals except after 12 h, revascularization group showed statistically significantly higher prevalence of no pain than endodontic treatment group. Regarding the healing; the periapical lesions decrease in size significantly from the pre-operative lesion size in both groups without significant difference between the both groups.

CONCLUSION

Within the limitation of this study, PRP revascularization could be an alternative treatment to root canal treatment but further randomized clinical trials with standardized techniques and long follow up periods are recommended for more reliable results.

Effect of platelet-rich fibrin (PRF) membranes on the healing of infected skin wounds

Tissue engineering focuses on wound healing and tissue regeneration. Platelet-rich fibrin (PRF) is a fibrin matrix containing cytokines, growth factors and cells that are gradually released into the wound over time. This study aimed to evaluate the effect of PRF membranes on wound repair and microbial control in infected wounds. Skin wounds were performed on the dorsum of rats using a 6 mm diameter metal punch. The defects were randomly assigned into four groups (n = 12/each) accordingly to the treatment: G1, noninfected wound filled only with clot; G2, noninfected wound with PRF; G3, infected wound (S. aureus) without PRF; G4, infected wound (S. aureus) with PRF. After 7 and 14 days, macroscopic and histological analyses of the wounds were performed. Furthermore, the quantification of β-defensin in PRF was measured by ELISA. At 14 days, the groups with PRF (G2 and G4) had wound sizes significantly smaller than the original defects (6 mm) (p < 0.05) and significantly smaller than those not treated with PRF, in both the infected and noninfected groups (p < 0.05). Furthermore, the groups with infected wounds (G3 and G4) demonstrated a significantly lower inflammation score in the PRF group than in the noninfected groups (p < 0.05). In vitro analysis of β-defensin was performed in all PRF membrane groups, and the median value was 1.444 pg/mL. PRF in the wounds of both control and infected rats played an important role in the modulation of tissue healing, most notably in infected sites.

Strategies to Improve AFT Volume Retention After Fat Grafting

BACKGROUND

Autologous fat grafting has gained increasing popularity used in plastic surgery as a strategy to improve functional and aesthetic outcome. However, variable augmentation results have concerned surgeons in that volume loss of grafted fat reported fluctuates unsteadily.

AIM

An optimal technique that clinically maximizes the long-term survival rate of transplantation is in urgent need to be identified.

METHOD

The PubMed/MEDLINE database was queried to search for animal and human studies published through March of 2022 with search terms related to adipose grafting encompassing liposuction, adipose graft viability, processing technique, adipose-derived stem cell, SVF and others.

RESULTS

45 in vivo studies met inclusion criteria. The principal of ideal processing technique is effective purification of fat and protection of tissue viability, such as gauze rolling and washing-filtration devices. Cell-assisted lipotransfer including SVF, SVF-gel and ADSCs significantly promotes graft retention via differentiation potential and paracrine manner. ADSCs induce polarization of macrophages to regulate inflammatory response, mediate extracellular matrix remodeling and promote endothelial cell migration and sprouting, and differentiate into adipocytes to replace necrotic cells, providing powerful evidence for the benefits and efficacy of cell-assisted lipotransfer.

CONCLUSION

Based on the current evidence, the best strategy can not be decided. Cell-assisted lipotransfer has great potential for use in regenerative medicine. But so far mechanically prepared SVF-gel is conducive to clinical promotion. PRP as endogenous growth factor sustained-release material shows great feasibility.

LEVEL OF EVIDENCE IV

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 .

Fibrin clot and Leukocyte-rich platelet-rich fibrin show similar release kinetics and amount of growth factors: a pilot study

BACKGROUND

In knee arthroscopic surgery, fibrin clot (FC) and leukocyte-rich platelet-rich fibrin (L-PRF) may be used in augmentation for meniscal repair. Studies have investigated growth factors released from FC and L-PRF; however, it is difficult to compare FC and L-PRF between different studies. Direct comparison of growth factors that may support meniscal healing released from FC and L-PRF may be beneficial in deciding whether to use FC or L-PRF. If no significant difference is seen, the surgeon may decide to use FC which is easier to prepare compared to L-PRF. The purpose of this pilot study is to investigate the release amount and pattern of basic fibroblast growth factor (bFGF), platelet-derived growth factor AB (PDGF-AB), transforming growth factor β1 (TGF-β1), vascular endothelial growth factor (VEGF), and stromal cell-derived factor 1 (SDF-1) from FC and L-PRF.

METHOD

Twenty milliliters (ml) of whole blood was collected from each of the four volunteers. Ten milliliters of whole blood was allocated for preparation of FC and 10 ml for L-PRF. FC and L-PRF were separately placed in 5 ml of culture media. Five milliliters of the culture media was sampled and refilled at 15 min, 1 day, 3 days, 1 week and 2 weeks. The collected culture was used to quantify bFGF, PDGF-AB, TGF-β1, VEGF, and SDF-1 release by Enzyme-linked immune-sorbent assay (ELISA). Mann-Whitney U test was performed to assess significance of differences in amount of each growth factor released between FC and L-PRF. Significance was accepted at P value less than 0.05.

RESULTS

At two weeks, the cumulative release of TGF-β1 was the highest among all the growth factors in both FC and L-PRF (FC:19,738.21 pg/ml, L-PRF: 16,229.79 pg/ml). PDGF-AB (FC: 2328 pg/ml, L-PRF 1513.57 pg/ml) had the second largest amount, followed by VEGF (FC: 702.06 pg/ml, L-PRF 595.99 pg/ml) and bFGF (FC: 23.48 pg/ml, L-PRF 18.2 pg/ml), which order was also common in both FC and L-PRF. No significant difference in final release amount and pattern was seen between FC and L-PRF.

CONCLUSION

The current pilot study showed that cumulative release amount and release pattern of PDGF-AB, VEGF, TGF-β1, and bFGF did not significantly differ between FC and L-PRF during the two weeks of observation.

An in vitro study into three different PRF preparations for osteogenesis potential

OBJECTIVE

To investigate the effect of Advanced Platelet-Rich Fibrin (A-PRF+), Leukocyte Platelet-Rich Fibrin (L-PRF), and injectable Platelet-Rich Fibrin (i-PRF) on osteogenesis of a human osteoblast-like cell line in vitro.

BACKGROUND

Different PRF protocols are used in clinical dentistry in the last years. Recent literature documented the positive impact of PRF derivatives in vivo and in vitro, on different types of cells. However, hardly any literature comparing the new protocols for PRF (the A-PRF+ and i-PRF) with the original protocol of PRF (L-PRF) is present for osteoblast-like cells.

MATERIALS AND METHODS

A-PRF+, L-PRF, and i-PRF were prepared from six male donors and pre-cultured with 10 mL culture medium for 6 days. 5 x 10³  cells/ml osteoblasts from the osteoblast cell line (U2OS) were seeded and cultured either with conditioned medium derived from the different PRF conditions or with regular culture medium. At five different time points (0, 7, 14, 21, 28 days), the osteogenic capacity of the cells was assessed with Alizarin Red S to visualize mineralization. Also in these cells, the calcium concentration and alkaline phosphatase activity were investigated. Using qPCR, the expression of alkaline phosphatase, osteocalcin, osteonectin, ICAM-1, RUNX-2, and collagen 1a was assessed.

RESULTS

In osteoblast-like cells cultured with conditioned medium, the A-PRF+ conditioned medium induced more mineralization and calcium production after 28 days of culturing compared with the control (p < .05). No significant differences were found in the extent of cell proliferation between the different conditions. RUNX-2 and osteonectin mRNA expression in the cells were lower in all PRF-stimulated cultures compared with control at different time points. The i-PRF-conditioned medium induced more ALP activity (p < .05) compared with control and osteoblasts-like cells differentiated more compared with osteoblasts cultured with L-PRF.

CONCLUSIONS

The three PRF preparations seem to have the capacity to increase the osteogenic potential of osteoblast-like cells. A-PRF+ seems to have the highest potential for mineralization, while i-PRF seems to have the potential to enhance early cell differentiation.

Efficacy of injectable platelet-rich fibrin (i-PRF) for gingival phenotype modification: a split-mouth randomized controlled clinical trial

OBJECTIVES

Gingival phenotype is decisive in periodontal health, aesthetics, and function and is a predictor of treatment outcomes. Injectable platelet-rich fibrin is a recently proposed method of gingival augmentation due to its enhanced regenerative potential. The objective of the present study was to evaluate the efficacy of injectable platelet-rich fibrin for gingival phenotype modification.

MATERIALS AND METHODS

In this split-mouth study, 30 healthy volunteers with thin gingival biotypes in either maxillary or mandibular incisors were included. iPRF was prepared using 64 g relative centrifugal force for 3 min. i-PRF was injected into the attached gingiva using a 27-gauge disposable needle in relation to the test sites (n = 360), and contralateral sites were kept as control. Re-evaluation was done at the end of 3 and 6 months. Post-operative complications and patient-reported experience measures were also recorded. Statistical analysis was done using paired t-test and analysis of covariance.

RESULTS

Statistically significant increase in gingival thickness was found in the test group at the individual site and tooth level. An overall increase in gingival thickness of 26.56% after 3 months and 29% after 6 months compared to baseline was noticed in the test group. No significant difference was found in the width of keratinized gingiva in any of the comparisons.

CONCLUSION

The non-surgical application of i-PRF is promising for enhancing gingival thickness. Future well-controlled studies with long-term follow-up in different patient populations can provide more evidence.

CLINICAL RELEVANCE

Gingival phenotype modification is a useful therapy to prevent the occurrence of gingival recession in patients with thin phenotypes.

TRIAL REGISTRATION

Clinical Trial Registration Number: CTRI/2021/04/032650.

Can platelet-rich fibrin act as a natural carrier for antibiotics delivery? A proof-of-concept study for oral surgical procedures

OBJECTIVES

Evaluate the role of platelet-rich fibrin (PRF) as a natural carrier for antibiotics delivery through the analysis of drug release and antimicrobial activity.

MATERIALS AND METHODS

PRF was prepared according to the L-PRF (leukocyte- and platelet-rich fibrin) protocol. One tube was used as control (without drug), while an increasing amount of gentamicin (0.25 mg, G1; 0.5 mg, G2; 0.75 mg, G3; 1 mg, G4), linezolid (0.5 mg, L1; 1 mg, L2; 1.5 mg, L3; 2 mg, L4), vancomycin (1.25 mg, V1; 2.5 mg, V2; 3.75 mg, V3; 5 mg, V4) was added to the other tubes. At different times the supernatant was collected and analyzed. Strains of E. coli, P. aeruginosa, S. mitis, H. influenzae, S. pneumoniae, S. aureus were used to assess the antimicrobial effect of PRF membranes prepared with the same antibiotics and compared to control PRF.

RESULTS

Vancomycin interfered with PRF formation. Gentamicin and linezolid did not change the physical properties of PRF and were released from membranes in the time intervals examined. The inhibition area analysis showed that control PRF had slight antibacterial activity against all tested microorganisms. Gentamicin-PRF had a massive antibacterial activity against all tested microorganisms. Results were similar for linezolid-PRF, except for its antibacterial activity against E. coli and P. aeruginosa that was comparable to control PRF.

CONCLUSIONS

PRF loaded with antibiotics allowed the release of antimicrobial drugs in an effective concentration. Using PRF loaded with antibiotics after oral surgery may reduce the risk of post-operative infection, replace or enhance systemic antibiotic therapy while preserving the healing properties of PRF. Further studies are needed to prove that PRF loaded with antibiotics represents a topical antibiotic delivery tool for oral surgical procedures.

Advanced Platelet-Rich Fibrin and Connective Tissue Graft for Treating Marginal Tissue Recessions: A Randomized, Controlled Split-Mouth Study

OBJECTIVES

 This study aimed to evaluate and compare the clinical outcomes of advanced platelet-rich fibrin (A-PRF) and connective tissue graft (CTG) in treating marginal tissue recessions.

MATERIALS & METHODS

 Fifteen patients with isolated bilateral maxillary gingival recessions were recruited for the study, with 30 defects. The defects were classified as Miller's class I/II gingival recession on the canine or premolar region. Patients were randomly divided into two groups, each receiving one of the two treatment techniques (A-PRF or CTG) on a different side of the maxilla in a split-mouth design. Clinical parameters such as recession height (RH), recession width (RW), probing pocket depth (PPD), clinical attachment level (CAL), a width of attached gingiva (WAG), and keratinized tissue height (KTH) were evaluated at baseline, 3, and 6 months. Changes in biotype, Recession Esthetic Score (RES), and Visual Analogue Score-Esthetics (VAS-E) were also evaluated at 6 months.

TRIAL REGISTRATION

 Ethics approval number (Helsinki): PHRC/HC/877/21 and registered at the Clinical Trials Registry under the number NCT05267015 Results: At the end of 6 months, there was a statistically significant reduction in RH and RW in both groups, with the mean RC% of 69.2±22.91, and 88.66±33.18 in Groups I and II, respectively. Intergroup analysis showed statistically significant differences in recession parameters between groups at 3 and 6 months, with better outcomes for the CTG group.

CONCLUSIONS

 This study demonstrates that A-PRF and CTG effectively manage gingival recession defects. However, CTG resulted in better clinical outcomes in terms of reduction in recession height and width.

Antimicrobial effect against Aggregatibacter actinomycetemcomitans of advanced and injectable platelet-rich fibrin from patients with periodontal diseases versus periodontally healthy subjects

Objectives

Advanced platelet-rich fibrin (A-PRF+) and injectable platelet-rich fibrin (i-PRF) have recently been developed and used in periodontal therapy. Few studies have contrasted the antibacterial effectiveness of these autologous materials derived from individuals with healthy gums, gingivitis, and periodontitis. This study aimed to compare the antimicrobial effects of these PRF materials against the periodontal pathogenic bacterium Aggregatibacter actinomycetemcomitans (Aa) in patients with different periodontal conditions.

Methods

Blood samples were collected from periodontally healthy individuals, patients with gingivitis, or patients with periodontitis to prepare A-PRF+ and i-PRF. The antibacterial capacity of these materials was evaluated through antibiofilm formation, biofilm susceptibility, and the time-kill assay over a 48-h period.

Results

A-PRF+ and i-PRF from each patient groups interfered with Aa's ability to form biofilm on the test tube surface, and the effect of i-PRF was significantly different among the patient groups. In contrast, these plasma preparation had a weak impact on mature biofilm. For products from the gingivitis and periodontitis groups, these effects were significantly stronger for i-PRF than A-PRF+ (p = 0.012 and p = 0.004, respectively). All plasma preparations inhibited Aa growth in the first 12 h after application, and i-PRF exhibited a significantly greater antimicrobial effect than A-PRF + at each time point.

Conclusion

A-PRF+ and i-PRF in all three patient groups could inhibit the growth of Aa in vitro, and i-PRF from patients with periodontitis exhibited a more significant effect than PRF from the other groups.

Comparative histological evaluation of two PRF formulations (PRF High and PRF Medium) on quality of life and healing outcome of apicomarginal defects: A randomized clinical trial

The objective of this randomized clinical trial was to investigate the effects of two PRF formulations (PRF High and PRF Medium) on quality of life and healing outcome (2D and 3D) of apicomarginal defects. Patients presenting with endodontic lesions and concomitant periodontal communication were randomly allocated to PRF High and PRF Medium groups. The treatment protocol in each group included a periapical surgical procedure with placement of PRF clot and membrane in the bony defect and on the denuded root surface, respectively. Quality of life was assessed for 1 week after surgery following a modified version of the patient's perception questionnaire. Postoperative pain was assessed using a visual analog scale. Clinical and radiographic evaluations were performed using Rud and Molven 2D criteria and Modified PENN 3D criteria. Buccal bone formation was assessed using sagittal and corresponding axial sections in CBCT. Histological analysis was performed using hematoxylin and eosin (H and E) staining and attaching primary antibodies to tissue sections. In total, 40 patients were enrolled in the trial (N = 20 per group). PRF Medium group patients reported significantly less swelling on the 1st (p = 0.036), 2nd (p = 0.034), and 3rd (p = 0.023) days, and average pain on the 2nd (p = 0.031), 3rd (p = 0.03), and 4th (p = 0.04) days postoperatively. The difference in success rate for periapical healing was non-significant between the PRF Medium group (89.5%) and PRF High group (90%), in both 2D and 3D imaging (p = 0.957). The formation of buccal bone was observed in five cases (26.3%) and four cases (20%) in the PRF Medium and PRF High groups, respectively, with a non-significant difference (p = 0.575). PRF Medium clots had a loose fibrin structure with a significantly higher number of neutrophils (473.79 ± 82.89 per mm²) than PRF High clots, which had a dense structure and fewer neutrophils (253.15 ± 63.86 per mm²) (p = 0.001). Autologous platelet concentrates (APCs) promoted satisfactory periapical healing, with no significant difference between the groups. Within the limitations of the study, it seems that PRF Medium should be preferred over PRF High when the patients' quality of life is the priority.

A liquid chromatography-tandem mass spectrometry method for the quantification of ampicillin/sulbactam and clindamycin in jawbone, plasma, and platelet-rich fibrin: Application to patients with osteonecrosis of the jaw

Ampicillin in combination with sulbactam is a widely used drug choice for infection prophylaxis, especially in oral and maxillofacial surgery. Clindamycin serves as an alternative in patients with known allergy to β-lactam antibiotics. To ensure effective prophylaxis, it is important to achieve sufficiently high concentrations of active antibiotic substances in the tissues affected by the surgery. To this end, a LC-MS/MS method was developed and validated that allows the quantification of ampicillin, sulbactam and clindamycin in jawbone, plasma, and so-called platelet-rich fibrin (PRF). Validation was performed in accordance with the European Medicines Agency guidelines for bioanalytical method validation. For all matrices, sample processing was carried out by protein precipitation with acetonitrile or methanol 80%, containing the isotope labelled internal standards (IS) of the three drugs. Analytes were separated on a pentaflourophenyl column at 20 °C using gradient elution. Furthermore, detection was accomplished by electrospray ionisation in positive-ion mode (ampicillin, clindamycin and corresponding IS) and negative-ion mode (sulbactam and corresponding IS) in combination with multiple reaction monitoring. Depending on the analyte and the matrix under investigation, calibration curves ranged from 0.14 to 59.8 µg/g (jawbone - ampicillin), 2.0-1000 µg/mL (plasma - ampicillin), and 1.0-495 µg/mL (PRF - ampicillin). All analytes fulfilled the requirements of the guideline regarding sensitivity, linearity, selectivity, carryover, within-run and between run accuracy and precision, matrix effect and extraction recovery in all matrices. The method was successfully applied to measure concentrations of ampicillin, sulbactam and clindamycin in real-life samples obtained in routine clinical practice.

Comparison of the clinical efficacy of concentrated growth factor and advanced platelet-rich fibrin in the treatment of type I multiple gingival recessions: a controlled randomized clinical trial

OBJECTIVES

The purpose of this randomized controlled clinical trial was to compare and evaluate the clinical effects of concentrated growth factor (CGF) and advanced platelet-rich fibrin (A-PRF) applied together with coronally advanced flap (CAF) technique using a microsurgical approach in the treatment of type I multiple gingival recessions (GR).

MATERIALS AND METHODS

Sixteen patients with multiple recession defects (Cairo type I) were included in this randomized and controlled study. Forty-five gingival recession defects were randomly equally divided into three groups (n = 15): CAF + CGF (test site); CAF + A-PRF (test site), and CAF alone (control site). Clinical attachment level (CAL), vertical gingival recession (VGR), horizontal gingival recession (HGR), gingival thickness (GT), width of keratinized gingiva (KGW), percentages of the mean (MRC), and complete root coverage (CRC), patient esthetic score (PES), and hypersensitivity score (HS) were recorded at baseline and 6 months after surgery. Patient comfort score (PCS) was evaluated at the day of surgery.

RESULTS

Significant improvements were determined in CAL, VGR, HGR, KGW, and GT at 6 months when compared to baseline levels in intra-group comparisons for all groups, and also GT was increased in CAF + A-PRF and CAF + CGF compared to CAF alone at 6 months in intergroup comparisons (p < 0.05). At 6 months, MRC was detected 85.66 ± 22.68% in the CAF + CGF, 90.88 ± 20.87% in the CAF + A-PRF, and 75.10 ± 32,37% in the CAF alone, and a significant increase was detected in the CAF + A-PRF group compared to CAF alone (p < 0.05). CRC in CAF + CGF was 66.66%, in CAF + A-PRF 80% and in CAF alone was 53.33% (p > 0.05). PES and HS values showed significant improvement from baseline to 6 months for all groups and also in CAF + CGF and CAF + A-PRF compared to CAF alone at 6 months in intergroup comparisons (p < 0.05).

CONCLUSIONS

The present study showed that the use of A-PRF and CGF membranes in GR therapy may have an additional benefit in GT increase and also A-PRF may increase the percentages of MRC. The use of A-PRF and CGF membranes may be beneficial in terms of improving patient-related parameters.

CLINICAL RELEVANCE

A-PRF and CGF may be superior to CAF alone in terms of patient-related parameters and GT increase in multiple recession defects.

TRIAL REGISTRATION NUMBER

17578e02-00a9-4a41-8c8d-42a637143531.

Regenerative Endodontic Management of an Immature Necrotic Premolar Using Advanced Platelet-Rich Fibrin

Regenerative endodontic management is a feasible treatment for immature teeth with periapical radiolucency and necrotic pulp that simplifies continued root creation. Among the most prevalent health problems in an immature root is dental pulp necrosis, which is caused by caries, improper endodontic treatments, and trauma. Necrosis of the dental pulp can affect long-term tooth survival and preservation and serve as a source of bacteria infecting the periapical tissue and the maxillofacial space. Here, we report on the application of advanced platelet-rich fibrin plus (A-PRF+) therapy, as a regenerative endodontic treatment (RET), in a 12-year-old with necrotic pulp and asymptomatic apical periodontitis. Over a 24-month follow-up post-treatment, we observed resolving of symptoms and a complete root formation with considerable periapical healing.

Direct Pulp Capping with Advanced Platelet-Rich Fibrin: A Report of Two Cases

This article aims to prove dentin bridge formation in two cases after direct pulp capping in reversible pulpitis using the platelet concentrate A-PRF+ and preservation of the vitality of the dental pulp. The hemostasis process for the pulp wound and cavity disinfection with gaseous ozone was performed under anesthesia. A large A-PRF+ membrane was prepared from blood plasma and applied to the pulp wound. After placing an MTA, the cavity was closed using glass-ionomer cement. Clinical and cone beam computed tomography findings demonstrated the formation of a dentin bridge in both cases. After the definitive restoration was conducted during the sixth month, the teeth from both patients were asymptomatic and had normal electric pulp testing values. Conclusions: Via clinical and CBCT examinations, we observed the dentin bridge formation after placing the platelet concentrate A-PRF+ in both cases. The vitality of the dental pulp was preserved. Further research is needed to refine the clinical protocol, recommended period for control examination, clarification of the precise indications of platelet concentrates, etc.

Evolution and Clinical Advances of Platelet-Rich Fibrin in Musculoskeletal Regeneration

Over the past few decades, various forms of platelet concentrates have evolved with significant clinical utility. The newer generation products, including leukocyte-platelet-rich fibrin (L-PRF) and advanced platelet-rich fibrin (A-PRF), have shown superior biological properties in musculoskeletal regeneration than the first-generation concentrates, such as platelet-rich plasma (PRP) and plasma rich in growth factors. These newer platelet concentrates have a complete matrix of physiological fibrin that acts as a scaffold with a three-dimensional (3D) architecture. Further, it facilitates intercellular signaling and migration, thereby promoting angiogenic, chondrogenic, and osteogenic activities. A-PRF with higher leukocyte inclusion possesses antimicrobial activity than the first generations. Due to the presence of enormous amounts of growth factors and anti-inflammatory cytokines that are released, A-PRF has the potential to replicate the various physiological and immunological factors of wound healing. In addition, there are more neutrophils, monocytes, and macrophages, all of which secrete essential chemotactic molecules. As a result, both L-PRF and A-PRF are used in the management of musculoskeletal conditions, such as chondral injuries, tendinopathies, tissue regeneration, and other sports-related injuries. In addition to this, its applications have been expanded to include the fields of reconstructive cosmetic surgery, wound healing in diabetic patients, and maxillofacial surgeries.

Progressive Platelet Rich Fibrin tissue regeneration matrix: Description of a novel, low cost and effective method for the treatment of chronic diabetic ulcers-Pilot study

INTRODUCTION

Chronic lower limb ulcers (CLLU) are those injuries that persist for more than six weeks despite adequate care. They are relatively common; it is estimated that 10/1,000 people will develop CLLU in their lifetime. Diabetic ulcer, because of its unique pathophysiology (association between neuropathy, microangiopathy, and immune deficiency), is considered one of the most complex and difficult etiologies of CLLU for treatment. This treatment is complex, costly, and sometimes frustrating, as it is often ineffective, which worsens the quality of life of patients and makes its treatment a challenge.

OBJECTIVE

To describe a new method for treating diabetic CLLU and the initial results of using a new autologous tissue regeneration matrix.

METHOD

This is a pilot, prospective, an interventional study that used a novel protocol of autologous tissue regeneration matrix for the treatment of diabetic CLLU.

RESULTS

Three male cases with a mean age of 54 years were included. A total of six Giant Pro PRF Membrane (GMPro) were used varying their application between one to three sessions during treatment. A total of 11 liquid phase infiltrations were performed varying their application between three and four sessions. The patients were evaluated weekly and a reduction in the wound area and scar retraction was observed during the period studied.

CONCLUSION

The new tissue regeneration matrix described is an effective and low-cost method for the treatment of chronic diabetic ulcers.

microRNAs Are Abundant and Stable in Platelet-Rich Fibrin and Other Autologous Blood Products of Canines

Various microRNAs (miRNAs) present in autologous blood products of canines have not been studied recently. We aimed to elucidate the existence of miRNAs in platelet-rich fibrin (PRF) and the stability of canine autologous blood products under various storage conditions. Total RNAs were isolated from PRF and other autologous blood products following newly adapted protocols used in commercial kits for plasma and tissue samples. Quantitative real-time polymerase chain reaction analysis (qPCR) was used to detect miRNAs in autologous blood products. The miR-16, miR-21, miR-155, and miR-146a were abundant in PRF and other autologous blood products of canines. Furthermore, we found they could maintain stability under protracted freezing temperatures of -30 °C for at least one month. Our findings revealed that PRF might be a stable resource for various canine miRNAs.

Platelet-Rich Fibrin Progressive Protocol: Third Generation of Blood Concentrates

PURPOSE

Platelet-rich fibrin (PRF) has been used in several fields of dentistry to improve tissue healing. However, PRF from glass tubes results in a limited number of small membranes, increasing clinical difficulty and work time. The aim of this study was to evaluate cell and platelet amounts and biomechanical strength of PRF-giant membranes produced from plastic tubes without additives.

MATERIAL AND METHODS

The investigators designed an ex vivo study, to compare 3 different centrifugation protocols for obtaining PRF: 700 × g/12 minutes (leukocyte and PRF [L-PRF]), 350 × g/14 minutes (GM350), and 60-700 × g more than 15 minutes total (progressive PRF [PRO-PRF]). We collected blood samples from 5 volunteers aged 25-54 years, over 3 different time periods (triplicate and paired study). From each venipuncture, 4 mL of blood was collected in vacutainers with ethylenediamine tetraacetic acid (EDTA) and approximately 104 mL in 12 plastic tubes without additives, which were separated into 3 groups, as per the centrifugation protocols (n = 5): L-PRF, GM350, and PRO-PRF. The PRF from the tubes of the same protocol was aspirated and 9 mL were placed in polylactic acid (PLA) forms and 3 mL were placed in a glass receptacle. The membranes from PLA forms were tested for tensile strength and the membranes from glass receptacles were evaluated by histomorphometry, while platelets and leukocytes were counted for those in tubes with EDTA. Statistical analyses were performed using Shapiro-Wilk normality test and then a one-way repeated measures analysis followed by Tukey multiple comparisons test (α < 0.05).

RESULTS

In tensile analyses, PRO-PRF (0.85 ± 0.23 N) showed a significantly higher maximum breaking strength than L-PRF (0.61 ± 0.26 N, P = .01) and GM350 (0.58 ± 0.23 N, P < .01). The histomorphometry revealed no significant statistical difference in cell counts between the groups (P = .52). Furthermore, there was no significant difference between the leukocyte (P = .25) and platelet counts (P = .59) in whole blood between the groups.

CONCLUSION

The progressive protocol (PRO-PRF) enabled the production of PRF giant membranes with greater tensile strength and adequate cell distribution. Moreover, it allows biomaterial incorporation during production and enables clinical control of membrane thickness and size as per the surgical procedure.

The Use of Polymers to Enhance Post-Orthodontic Tooth Stability

Relapse after orthodontic treatment occurs at a rate of about 70 to 90%, and this phenomenon is an orthodontic issue that has not yet been resolved. Retention devices are one attempt at prevention, but they require a considerable amount of time. Most orthodontists continue to find it challenging to manage orthodontic relapse; therefore, additional research is required. In line with existing knowledge regarding the biological basis of relapse, biomedical engineering approaches to relapse regulation show promise. With so many possible uses in biomedical engineering, polymeric materials have long been at the forefront of the materials world. Orthodontics is an emerging field, and scientists are paying a great deal of attention to polymers because of their potential applications in this area. In recent years, the controlled release of bisphosphonate risedronate using a topically applied gelatin hydrogel has been demonstrated to be effective in reducing relapse. Simvastatin encapsulation in exosomes generated from periodontal ligament stem cells can promote simvastatin solubility and increase the inhibitory action of orthodontic relapse. Moreover, the local injection of epigallocatechin gallate-modified gelatin suppresses osteoclastogenesis and could be developed as a novel treatment method to modify tooth movement and inhibit orthodontic relapse. Furthermore, the intrasulcular administration of hydrogel carbonated hydroxyapatite-incorporated advanced platelet-rich fibrin has been shown to minimize orthodontic relapse. The objective of this review was to provide an overview of the use of polymer materials to reduce post-orthodontic relapse. We assume that bone remodeling is a crucial factor even though the exact process by which orthodontic correction is lost after retention is not fully known. Delivery of a polymer containing elements that altered osteoclast activity inhibited osteoclastogenesis and blocking orthodontic relapse. The most promising polymeric materials and their potential orthodontic uses for the prevention of orthodontic relapse are also discussed.

Fluid Platelet-Rich Fibrin (PRF) Versus Platelet-Rich Plasma (PRP) in the Treatment of Atrophic Acne Scars: A Comparative Study

Platelet-rich fibrin (PRF), a second-generation platelet concentrate, was developed for the purpose of overcoming the limitations of Platelet-rich plasma (PRP). PRF can produce a higher cumulative release of growth factors than PRP. Also, this release is slow and prolonged, making it ideal for tissue regeneration and growth stimulation. This study was conducted to evaluate the efficacy of fluid PRF either alone or combined with needling versus PRP in the treatment of atrophic acne scars. A comparative study including 30 patients with atrophic acne scars who were divided into two equal groups. Group I included 15 patients in which the left side of the face was treated with intradermal injection of PRP while the right side was treated with combined needling with PRP. Group II included15 patients in which the left side of the face was treated with intradermal injection of fluid PRF while the right side was treated with combined needling with fluid PRF. All patients received four sessions with 3 weeks interval. The acne scars significantly improved in both sides of face in both groups. According to quartile grading scale and patient satisfaction; the therapeutic response was significantly higher in PRF group than PRP either alone or combined with needling. The combination with needling increases efficacy of PRF and PRP. Fluid PRF is highly effective, safe and simple procedure that can be used instead of PRP in the treatment of acne scars.

Autologous blood products: Usage and preparation protocols

FOCUSED CLINICAL QUESTION

What are the appropriate preparation protocols for autologous blood products to support their clinical utilization?

SUMMARY

Autologous blood products provide a unique clinical benefit. Their popularity among the professions is growing. However, as this is a rapidly evolving field, multiple modalities are presented within the literature. Frequently there is no demonstrated superiority to previous iterations. This brief review attempts to offer a concise chronology on their evolution, preparation, and where possible, evidence to support their clinical utilization.

CONCLUSIONS

The field of autologous blood products is expanding rapidly. These products appear to yield variable clinical benefits in specific indications. However, evidence supporting their universal application is scant, and the superiority of one formulation versus another is yet to be demonstrated.

Solid PRF Serves as Basis for Guided Open Wound Healing of the Ridge after Tooth Extraction by Accelerating the Wound Healing Time Course-A Prospective Parallel Arm Randomized Controlled Single Blind Trial

Systematic evaluations regarding the influence of PRF in ridge sealing are still lacking. To the best of our knowledge, this is the first systemic randomized, controlled, clinical approach dealing with the potential of a systematic applied solid PRF on soft tissue socket healing of molar and premolar extraction sockets with evaluation for up to 90 days. Qualitative and quantitative image analysis showed that PRF contributed to a significantly faster ridge sealing, within the period of 7-10 days in both tooth types. This led to a visibly less contraction at the PRF-treated group sites at day 90. Patients' pain perception demonstrated no statistic significance between both groups (PRF vs. natural healing), but the patients in PRF group seemed to have had less pain throughout the observational period. It becomes evident that PRF is able to serve as a promotor of the secondary wound healing cascade. The guiding capacity of PRF accelerating the process of open ridge healing makes it possible to act as a natural growth factor drug delivery system, providing a more predictable guided open wound healing of the ridge with less contraction of the soft tissue, the latter being a key factor for the subsequent successful dental implantation and oral rehabilitation.

Peripheral mononuclear cells composition in platelet-rich fibrin in canines with chronic conditions

Platelet-rich fibrin (PRF) is a hot research topic because of its regenerative effect in humans. However, data reporting about its application in companion animals is lacking. The study aimed to supplement currently available data on PRF cell composition in canine patients by isolating peripheral blood mononuclear cells (PBMC), namely T cells, matured B cells, monocytes and macrophages, and adapting current protocols of cell flow cytometry for PRF analysis. The canine patient population was divided into three subgroups: animals with periodontitis only, animals with neoplasia and periodontitis, and healthy controls. Individual clinical parameters of the patients and evaluation of the wound healing quality were included in the research. In the present study, canine PRF cell composition was analyzed for the first-time using cell flow cytometry protocol. A higher proportion of PBMC cells related to wound healing (CD3+, CD3+ CD4+ CD8-, CD14+) were found in the PRF of control, periodontitis and neoplasia groups compared to the respective blood samples, which implies a positive outcome associated with clinical PRF usage in canine patients. Proportions of monocytes and macrophages were higher in PRF samples compared to the blood of healthy patients and periodontitis-affected patients. However, inflammatory and neoplastic processes do not affect the distribution of PBMC.

In Vitro Assessment of Lyophilized Advanced Platelet-Rich Fibrin from Dogs in Promotion of Growth Factor Release and Wound Healing

Advanced platelet-rich fibrin (A-PRF) induces more proliferation and migration of fibroblasts compared with standard PRF, but it being freshly prepared prior to it being applied is necessary. Therefore, this study aimed to determine the effect of lyophilized A-PRF on growth factor release and cell biological activity. Blood samples were collected from six dogs and processed for fresh and lyophilized A-PRF. The growth factors released included transforming growth factor beta-1 (TGF-β1), vascular endothelial growth factor-A (VEGFA), and platelet-derived growth factor-BB (PDGF-BB), and the fibroblast proliferation as well as wound closure enhancement of both products were compared. The results showed that TGF-β1, PDGF-BB, and VEGFA were continually released from lyophilized A-PRF for over 72 h. Lyophilized A-PRF released significantly more accumulated VEGEA and a tendency to release more TGF-β1 at 72 h as well as VEGFA at 24 h and 72 h than fresh A-PRF. Moreover, lyophilized A-PRF increased fibroblast proliferation and induced a significantly faster wound closure than the control, while no significant difference between fresh and lyophilized A-PRF was found. In conclusion, the lyophilization of canine A-PRF can preserve the release of growth factors and has similar biological activities to a fresh preparation. This encourages the substitution of lyophilized A-PRF instead of fresh A-PRF in regenerative treatments in which the stability of the product is concerned.

Combination of Advanced Platelet-Rich Fibrin and Pentoxifylline/Tocopherol as a Novel Preventive Option in Osteoradionecrosis: A Case Report

Osteoradionecrosis (ORN) of the jaws is an uncommon complication of radiation therapy that seriously affects the oral and maxillofacial region. Management of ORN is intrinsically difficult and treatment effects are unpredictable. ORN can be treated with pentoxifylline/tocopherol and autologous platelet concentrates to promote wound healing. Furthermore, the low speed of relative centrifugal forces platelet-rich fibrin (PRF + ) has been shown high efficacy for ORN. A 72-year-old male patient with history of radiation treatment for squamous cell carcinoma in the left side of the tongue. Six years after the treatment, his upper right first molar tooth (no. 16) was surgically extracted due to persistent pain. A few months following the extraction, intraoral examination showed gingival inflammation, and pain when palpation around the edentulous area of tooth no. 16. Radiological examination revealed retained root of 16 with radiolucent area and horizontal bone loss around upper right second molar tooth (no. 17). Pentoxifylline and tocopherol were given for a week before the surgical operation and were continued for 8 weeks after the operation. Retained roots of teeth no. 16 and 17 were removed and the sockets were debrided, the advanced PRF+ (A-PRF + ) membranes were placed followed by primary wound closure. Following 2 weeks of treatment, the mucosa healed and progressed to complete mucosal coverage at 2 months with no pathological findings or ORN progression. At 6-month follow-up, clinical and cone-beam computed tomography (CBCT) revealed no pathology. Our case demonstrates that the combination of pentoxifylline/tocopherol and the A-PRF+ surgical approach can be useful for wound healing and prevention of ORN.

Platelet Rich Fibrin Membrane Grafting After Laser Excision for Oral Mucosal Lesions

Platelet rich fibrin (PRF) is a novel surgical biomaterial which has shown immense healing and regenerative potential with diverse clinical applications. Surgical excision is a routinely employed treatment modality for mucosal oral lesions with or without grafting or repair of the base of the wound. We proposed a hypothesis that covering of the base of excised lesion with this platelet rich fibrin membrane can accelerate the rate of physiological healing process and regeneration. To evaluate the role, efficacy, advantages and adverse effects if any, of placement of PRF membrane grafts over surgical excision sites of oral mucosal lesions. Platelet rich fibrin membrane graft was prepared as per recommendation and established protocols. Patients were selected for surgical excision of localized, superficial oral mucosal lesions after meticulous clinical and radiological considerations and informed consent was taken. After laser excision with safe margins, the base of wound was covered with PRF membrane graft, stitched in place by 3-0 vicryl sutures. The operated site was clinically evaluated at regular intervals and a healing score was calculated and statistically tabulated on the basis of various parameters of healing. A total of 34 patients were included in the study with a male preponderance (21 males and 13 females). Satisfactory and clinically acceptable wound healing was observed in most of the patient with minimal morbidities. Surgical site demonstrated good healing score and clinically complete healing with good epithelialisation was achieved in all patients. Platelet rich fibrin membrane is an effective grafting biomaterial after excision of oral mucosal lesions as it enhances the rate of healing with minimal complications. We recommend further multicentre studies with higher sample size to explore its utility and clinical applications in different avenues of oral and head neck surgery.

A Bibliometric Analysis of Platelet-Rich Fibrin in Dentistry

Platelet-rich fibrin (PRF), a second-generation platelet concentrate, has been widely recognized in numerous studies for its performance of wound healing and regeneration in dentistry. However, bibliometric analysis of PRF in dentistry is still scarce. Thus, this study aimed to conduct and delineate a bibliometric analysis of the application of PRF and its changing trend in dentistry. All papers concerning PRF up to 30 June 2022 were included in the literature search from the Web of Science Core Collection database. These data were then entered into Microsoft Excel, analyzed by the SAS statistical software, and visualized by the VOSviewer software. A total of 562 articles were retrieved following the exclusive criteria. The results demonstrated that the trend of annual publication increased continually (p for trend < 0.01), more notably in the last five years. The majority of the articles were original (58.01%), followed by reviews (17.08%), and case reports (10.14%). The three major study designs were clinical studies (20.11%), randomized controlled trials (17.62%), and review/meta-analysis (17.08%). PRF was most frequently employed in oral surgery (31.14%), periodontal regeneration (22.42%), and implant therapy (18.68%). Turkey (16.19%), India (12.28%) and China (7.12%) were the top 3 countries publishing PRF studies. By comparing the total number of publications, total citation counts and varying counting methods, a combination of numerous counting methods was suggested for use since each counting method yields different results. Taken together, we hope with these informative findings, researchers could focus on the future direction or advancement in PRF, laying a foundation for evidence-based dentistry.

Effectiveness of platelet-rich concentrates on the rate of orthodontic tooth movement: a systematic review and meta-analysis

BACKGROUND

Autologous platelet-rich concentrates (PRCs) are recently used as a local biological substance in orthodontics to accelerate the rate of tooth movement.

OBJECTIVES

This systematic review aimed to evaluate the effects of PRCs on the rate of orthodontic tooth movement (OTM).

SEARCH METHODS

Unrestricted search of five electronic databases supplemented by the manual and gray literature search were undertaken in March 2022.

SELECTION CRITERIA

Randomized controlled trials (RCTs) evaluating the effect of PRCs on the rate of OTM with their side effect were included in this systematic review.

DATA COLLECTION AND ANALYSIS

Data items were extracted by two authors using a pre-piloted extraction form. Similar outcomes within a comparable time frame were synthesized in a meta-analysis.

RESULTS

Fourteen studies were deemed eligible for inclusion and seven RCTs were pooled in a meta-analysis. Canine retraction rate was higher in the side of PRCs injection than the control side by 0.28 mm/month (95% CI: 0.16-0.40, I2 = 95.6 per cent, P < 0.001, 345 patients) in the first 4 months after PRCs injection. There was no statistically significant difference between the PRCs side and the control side regarding molar anchorage loss (MAL) (MD = 0.03 mm, 95% CI: -0.18 to 0.24, I2 = 46.3 per cent, P = 0.78, 44 patients), canine rotation (MD = -0.19o, 95% CI: -1.95 to 1.57, I2 = 45.4 per cent, P = 0.96, 48 patients), or en-masse retraction. Likewise, there was no difference between both groups in terms of the duration of de-crowding. The mandibular canine retraction was statistically higher on the PRCs side than on the control side by 0.17 mm/month (P < 0.001, one trial). Regarding root resorption, there was no statistically significant difference between the experimental and control sides within the follow-up time. Mild pain scores were reported by the patients in the first 24 hours after injections.

CONCLUSIONS

Low-level evidence indicates that the effect of PRCs on OTM is minor and clinically insignificant. The findings should be interpreted with caution due to the inherent limitations in the included RCTs.

REGISTRATION

PROSPERO (CRD42022300026).

THE EVIDENCE IS UNCLEAR ON THE EFFECTIVENESS OF PLATELET RICH FIBRIN IN SOCKET PRESERVATION

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Al-Maawi, S, Becker, K, Schwarz, F, Sader R, Ghanaati, S. Efficacy of platelet-rich fibrin in promoting the healing of extraction sockets: a systematic review. Int J Implant Dent 7, 117 (2021). https://doi.org/10.1186/s40729-021-00393-0 SOURCE OF FUNDING: This study was self-funded by the author TYPE OF STUDY/DESIGN: Systematic review (SR).

Promoting repair of highly purified stromal vascular fraction gel combined with advanced platelet-rich fibrin extract for irradiated skin and soft tissue injury

Background

To evaluate the effect of highly purified stromal vascular fraction gel (SVFG) combined with advanced platelet-rich fibrin extract (APRFE) in treatment of irradiated skin and soft tissue injury.

Methods

The subcutaneous fat and whole blood of 4 rabbits were collected to isolate the SVFG and APRFE, respectively. Forty-eight rabbits were divided into 4 groups to prepare irradiated skin injury models with 25 Gy for 24 hours; corresponding dose were performed subcutaneously injected into wounds. In group A, the rabbits were treated with 0.3 mL APRFE combined with 1 mL SVFG. In group B, the rabbits were treated with 1 mL SVFG. In group C, the rabbits were treated with 0.3 mL APRFE, and group D was treated with 1 mL normal saline. The wound healing was detected on the 2, 5, 9 and 14 d after intervention. The wounds tissue was cut for hematoxylin and eosin (HE) staining to observe the structure and Masson staining to observe the collagen content. The expression of CD31 in each group was detected by immunohistochemistry (IHC), the protein and mRNA levels of K19, hypoxia inducible factor-1 alpha (HIF-1α), vascular endothelial growth factor (VEGF), interleukin 8 (IL-8) and interleukin 10 (IL-10) were detected respectively by Western blot (WB) and reverse transcription-polymerase chain reaction (RT-PCR) on 7, 14 and 28 d after intervention.

Results

It is revealed that wound healing rates from 5 to 14 d in group A was significantly higher than that of control. The wounds healing rates in group B and C were significantly higher than that of control after 12 d. Masson staining results showed that the collagen content in group A was significantly higher than that of the other 3 groups on the 7, 14 and 28 d. The results of IHC showed that the expression of CD31 in group A was significantly higher than that of the other 3 groups on 7, 14 and 28 d. WB and RT-PCR results showed that relative expression levels of K19, HIF-1α, VEGF, IL-10 in group A were significantly higher than that of the other 3 groups on 7, 14 and 28 d. However, the relative expression levels of IL-8 in group A was significantly lower than that of the other 3 groups on 7, 14 and 28 d.

Conclusions

SVFG combined with APRFE can promote the repair of irradiated skin and soft tissue injury by accelerating angiogenesis, promoting collagen synthesis and reducing inflammation.

Emerging roles of platelet concentrates and platelet-derived extracellular vesicles in regenerative periodontology and implant dentistry

Platelet concentrates (PCs) are easily obtained from autogenous whole blood after centrifugation and have evolved through three generations of development to include platelet-rich plasma, platelet-rich fibrin, and concentrated growth factor. Currently, PCs are widely used for sinus floor elevation, alveolar ridge preservation, periodontal bone defects, guided bone regeneration, and treatment of gingival recession. More recently, PCs have been leveraged for tissue regeneration to promote oral soft and hard tissue regeneration in implant dentistry and regenerative periodontology. PCs are ideal for this purpose because they have a high concentration of platelets, growth factors, and cytokines. Platelets have been shown to release extracellular vesicles (P-EVs), which are thought to be essential for PC-induced tissue regeneration. This study reviewed the clinical application of PCs and P-EVs for implant surgery and periodontal tissue regeneration.

Injectable Platelet-Rich Fibrin - A Revolution in Periodontal Regeneration

As of a few years ago, platelet concentrates have been applied in a variety of medical and dental procedures. A notable aspect is that platelet-rich fibrin (PRF) is the most commonly utilized platelet concentrate in the field of dentistry. The most significant modification that was used over the years but had the biggest impact was injectable platelet-rich fibrin (I-PRF), which has more special properties. Additionally, the results of this I-PRF have been useful. The solid platelet-rich fibrin (PRF), which is a noticeable feature and has a low speed and duration in centrifugation, is the main advantage of I-PRF. I-PRF is primarily found in liquid form as PRF. It facilitates the quickening of increased vascularization and aids in accelerating the healing of wounds. An autologous blood concentration known as I-PRF has been known for many years.

The advantage of I-PRF is that it exhibits constant release of growth factors and promotes cell migration by announcing the expression of type I collagen and transforming growth factor mRNA. The majority of the time, plastic and orthopedic operations use injectable platelet aggregates. It also reduces adverse reactions to transplanted material as compared to other grafting techniques. Additionally, it makes numerous other operations, like regenerative ones, much better options. In circumstances where it has been noticed, I-PRF is helpful and crucial in periodontics for bone regeneration and wound healing. It is therefore not difficult to predict that this fully autologous blood concentrate, which is now being utilized in numerous applications and requires little invasiveness, will become even more frequently used in the future. This review paper contains the differences between platelet-rich plasma (PRP) and PRF, the development of diverse platelets, and the use of I-PRF in periodontal therapy.

Third-Generation Platelet Concentrates in Periodontal Regeneration: Gaining Ground in the Field of Regeneration

Platelets are important for hemostasis and the healing of wounds. In clinical settings, healing cytokines including insulin-like growth factors (IGF), platelet-derived growth factors (PDGF), and transforming growth factors (TGF) are commonly implemented. The regenerative approach in dentistry frequently employs platelet concentrates (PCs) that are “autologous in origin” and have a high concentration of platelets, growth factors, and leukocytes. First-generation PCs is made of platelet-rich plasma (PRP), while second-generation PC is made of platelet-rich fibrin (PRF). Both have limitations, so modification protocols and development in PRP and PRF derivatives are required for advancement mechanisms, strength, biodegradability, retention ability in the field of regenerative dentistry, and so on. As third-generation PC, newer genera kinds of PRF, such as advanced-PRF (A-PRF), advanced-PRF+ (A-PRF+), injectable-PRF (i-PRF), and titanium-PRF (T-PRF), were introduced. A-PRF matrices in their solid form were introduced using the low-speed centrifugation concept (LSCC). The applied relative centrifugal force (RCF) for A-PRF is reduced to 208 g as a result of this improved preparation process. A-PRF features a greater number of neutrophil granules in the distal region, especially at the red blood cells-buffer coat (RBC-BC) interface, and the A-PRF clot has a more porosity-like structure with a bigger interfibrous space than PRF. Since the PRF is in a gel form and is difficult to inject, i-PRF was formulated to address this problem. Compared to the other two protocols, the i-PRF protocol requires far less time, and this is the advantage of this PC. This is because i-PRF just needs the blood components to be separated, which happens within the first two to four minutes. Compared to normal L-PRF, T-PRF creates fibrin that is thicker and more densely woven. Titanium has a higher hemocompatibility than glass, which could lead to greater polymerized fibrin formation. In periodontal regenerative operations, oral surgery, and implant dentistry, PRF and its newer advanced modifications have demonstrated promising results and desirable results in both soft and hard tissue regenerative techniques.

Do platelet concentrates accelerate orthodontic tooth movement?: a systematic review

PURPOSE

Surgical techniques in orthodontics have received widespread attention in recent years. Meanwhile, biomaterials with high molecular content have been introduced, such as platelet concentrates (PCs), which may accelerate orthodontic tooth movement (OTM) and reduce periodontal damage. The present systematic review aimed to answer the following PICO question: "In patients in whom orthodontic surgical techniques are performed (P), what is the effectiveness of using PCs over the surgical site (I) when compared to not placing PCs (C) to achieve faster tooth movement (O)?"

METHODS

A search was performed in 6 databases. The criteria employed were those described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses declaration. The present review included studies with a control group that provided information about the influence of PCs on the rate of OTM.

RESULTS

The electronic search identified 10 studies that met the established criteria.

CONCLUSIONS

The included studies were very diverse, making it difficult to draw convincing conclusions. However, a tendency was observed for OTM to be accelerated when PCs were used as an adjuvant for canine distalization after premolar extraction when distalization was started in the same session. Likewise, studies seem to indicate an association between PC injection and the amount of canine retraction. However, it is not possible to affirm that the use of PCs in corticotomy shortens the overall treatment time, as this question has not been studied adequately.

TRIAL REGISTRATION

PROSPERO Identifier: CRD42021278542.

Effects of advanced platelet-rich fibrin combined with xenogenic bone on human periodontal ligament stem cells

OBJECTIVES

In this study, we aimed to investigate the effects of a mixture of advanced platelet-rich fibrin (A-PRF) and xenogenic bone substitute material (XBSM) on the proliferation and migration of human periodontal ligament stem cells (hPDLSCs) based on the in vitro release of growth factors.

MATERIAL AND METHODS

The concentrations of platelet-derived growth factor-AB (PDGF-AB) and vascular endothelial growth factor (VEGF) released by the A-PRF-XBSM mixture were estimated using enzyme-linked immunoassay for up to 7 d. The A-PRF-XBSM mixture exudate was incubated with hPDLSCs. At Days 1, 3, 5, and 7, cell proliferation and migration were investigated by cell counting and wound-healing assays.

RESULTS

PDGD-AB and VEGF were released from the A-PRF-XBSM mixture exudate for up to 7 days. hPDLSCs were cultured in media with various concentrations of the A-PRF-XBSM mixture exudate and exhibited their proliferation and migration ability. Furthermore, the factors released from the 100% A-PRF-XBSM mixture exudate had a substantial effect on cell migration, whereas those released from 4% and 20% A-PRF-XBSM mixture exudates stimulated hPDLSC proliferation.

CONCLUSIONS

A-PRF-XBSM mixture continuously released growth factors over 7 days and enhanced hPDLSC proliferation and migration. Therefore, A-PRF in combination with XBSM might provide potential advantages for periodontal tissue regeneration.

Clinical and radiographic evaluation of low-speed platelet-rich fibrin (PRF) for the treatment of intra-osseous defects of stage-III periodontitis patients: a randomized controlled clinical trial

Aim

The current randomized controlled trial assessed for the first time the effect of a low-speed platelet-rich fibrin (PRF) with open flap debridement (OFD) versus OFD alone in the treatment of periodontal intra-osseous defects of stage-III periodontitis patients.

Methods

Twenty-two periodontitis patients with ≥ 6 mm probing depth (PD) and ≥ 3 mm intra-osseous defects were randomized into test (PRF + OFD; n = 11) and control (OFD; n = 11) groups. Clinical attachment level (CAL)–gain (primary outcome), PD-reduction, gingival recession depth (GRD), full-mouth bleeding scores (FMBS), full-mouth plaque scores (FMPS), radiographic linear defect depth (RLDD), and radiographic bone fill (secondary-outcomes) were examined over 9 months post-surgically.

Results

Low-speed PRF + OFD and OFD demonstrated significant intra-group CAL-gain and PD- and RLDD-reduction at 3, 6, and 9 months (p < 0.01). Low-speed PRF + OFD exhibited a significant CAL-gain of 3.36 ± 1.12 mm at 6 months (2.36 ± 0.81 mm for the control group; p < 0.05), and a significantly greater PD-reduction of 3.36 ± 1.12 mm at 3 months, of 3.64 ± 1.12 mm at 6 months and of 3.73 ± 1.19 mm at 9 months (2.00 ± 0.89 mm, 2.09 ± 1.04 mm, and 2.18 ± 1.17 mm in the control group respectively; p < 0.05). No significant differences were notable regarding GRD, FMPS, FMBS, RLDD, or bone fill between both groups (p > 0.05).

Conclusions

Within the current clinical trial’s limitations, the use of low-speed PRF in conjunction with OFD improved CAL and PD post-surgically, and could provide a cost-effective modality to augment surgical periodontal therapy of intra-osseous defects of stage-III periodontitis patients.

Clinical relevance

Low-speed PRF could provide a cost-effective modality to improve clinical attachment gain and periodontal probing depth reduction with open flap debridement approaches.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-022-04627-2.

Comparative evaluation of effect of injectable platelet-rich fibrin with collagen membrane compared with collagen membrane alone for gingival recession coverage

BACKGROUND

Collagen membrane and platelet-rich fibrin (PRF) have emerged as vital biomaterials in the field of periodontal regeneration. Minimally invasive techniques are being preferred by most periodontists, as it is patient compliant with fewer post-surgical complications as compared to conventional surgical techniques. Thus, in this study we have evaluated the effect of injectable PRF (i-PRF) with collagen membrane compared with collagen membrane alone using vestibular incision subperiosteal tunnel access (VISTA) technique for gingival recession coverage.

AIM

To compare the efficacy of VISTA using collagen membrane with collagen membrane soaked in injectable PRF for gingival recession coverage.

METHODS

A split mouth randomized controlled clinical trial was designed;13 subjects having at least 2 teeth indicated for recession coverage were enrolled in this study. The sites were randomly assigned to control group (VISTA using collagen membrane alone) and the test group (VISTA using collagen membrane with i-PRF). The clinical parameters assessed were pocket depth, recession depth (RD), recession width (RW), relative attachment level, keratinised tissue width (KTW), keratinised tissue thickness (KTT), and percentage root coverage.

RESULTS

RD showed a statistically significant difference between the test group at 3 mo (0.5 ± 0.513) and 6 mo (0.9 ± 0.641) and the control group at 3 mo (0.95 ± 0.51) and 6 mo (1.5 ± 0.571), with P values of 0.008 and 0.04, respectively. RW also showed a statistically significant difference between the test group at 3 mo (1 ± 1.026) and 6 mo (1.65 ± 1.04) and the control group at 3 mo (1.85 ± 0.875) and 6 mo (2.25 ± 0.759), with P values of 0.008 and 0.001, respectively. Results for KTW showed statistically significant results between the test group at 1 mo (2.85 ± 0.489), 3 mo (3.5 ± 0.513), and 6 mo (3.4 ± 0.598) and the control group at 1 mo (2.45 ± 0.605), 3 mo (2.9 ± 0.447), and 6 mo (2.75 ± 0.444), with P values of 0.04, 0.004, and 0.003, respectively. Results for KTT also showed statistically significant results between test group at 1 mo (2.69 ± 0.233), 3 mo (2.53 ± 0.212), and 6 mo (2.46 ± 0.252) and the control group at 1 mo (2.12 ± 0.193), 3 mo (2.02 ± 0.18), and 6 mo (1.91 ± 0.166), with P values of 0.001, 0.001, and 0.001, respectively. The test group showed 91.6%, 81.6%, and 67% root coverage at 1 mo, 3 mo, and 6 mo, while the control group showed 82.3%, 66.4%, and 53.95% of root coverage at 1 mo, 3 mo, and 6 mo, respectively.

CONCLUSION

The use of minimally invasive VISTA technique along with collagen membrane and injectable form of platelet-rich fibrin can be successfully used as a treatment method for multiple or isolated gingival recessions of Miller’s class-I and class-II defects.

Comparative Study of the Efficacy of Advanced Platelet-rich Fibrin and Standard Platelet-rich Fibrin in Mandibular Third Molar Surgery

Background

Disimpaction of mandibular of third molar is one of the commonest minor oral surgical procedures. Platelet-rich fibrin (PRF) plays a vital role in both hard and soft tissue healing. There are various subtypes of PRF used for different surgical sites.

Objective

The purpose of this study is to compare and evaluate the effectiveness of Advanced PRF (A-PRF) and Standard PRF (S-PRF) in the healing process of the surgical sites after the removal of mandibular third molars. Changes in swelling, pain, and mouth opening were evaluated.

Materials and Methods

10 patients (3 men, 7 women; 18-35 years old) were selected for the removal of bilateral impacted mandibular third molar teeth. A-PRF and S-PRF were placed in the right-hand side for 5 patients in each group. In both the groups, the left side of the patients was taken as the control group. Postoperative pain was measured using a visual analogue scale (VAS), postoperative swelling was calculated using the distance between multiple facial landmarks (method) and mouth opening measured interincisally on the 1st postoperative day, 3rd day, and the 7th day, respectively. SPSS version 26.0 was used for data analysis.

Results

Advanced PRF group recorded noteworthy improvement in pain (P = 0.063), swelling (P = 0.001), and mouth opening (P = 0.013) when compared to the standard PRF group. There was statistically substantial variance between the advanced PRF and standard PRF groups.

Conclusion

Advanced PRF group showed decreased swelling, pain, and increased mouth opening compared to standard PRF group.

Clinicoradiographic evaluation of advanced-platelet rich fibrin block (A PRF + i PRF + nanohydroxyapatite) compared to nanohydroxyapatite alone in the management of periodontal intrabony defects

Background:

Several bone grafting formulations have been given clinically acceptable outcomes in treating intrabony defects. Platelet rich fibrin (PRF), an autologous platelet concentrate holds potential to be used for regenerative treatment. The purpose of this study was to evaluate clinical and radiographic outcomes in periodontal intrabony defects treated with advanced-PRF block (A PRF + i PRF + nanohydroxyapatite [nHA]) compared to nHA alone.

Methods:

Twenty-eight sites in chronic periodontitis patients having probing pocket depth (PPD) ≥6 mm and 3 walled intrabony defects (depth of ≥3 mm) were selected, randomly allotted into two groups: Group A was treated with A-PRF block and Group B with nHA (Sybograf™). Clinical parameters including plaque index (PI), gingival index (GI), PPD, relative attachment level (RAL) and radiographically linear and volumetric defect fill were assessed using cone beam computed tomography at baseline and 6 months postoperatively.

Results:

Intragroup comparison using paired t-test and intergroup comparison using unpaired t-test was done. Group A demonstrated significantly higher reduction in PPD and gain in RAL when compared to Group B (P ≤ 0.05) at the end of 6 months. Similarly gain in bone volume was greater in Group A (0.1 ± 0.05) as compared to Group B (0.04 ± 0.02) (P ≤ 0.05).

Conclusion:

Advanced-PRF block showed significant clinical and radiographic improvement as compared to nHA alone which depicts that, it may be an ideal graft to be used for the treatment of periodontal intrabony defects.

Complementarity of surgical therapy, photobiomodulation, A-PRF and L-PRF for management of medication-related osteonecrosis of the jaw (MRONJ): an animal study

Background

This study aimed to evaluate the complementarity of surgical therapy, photobiomodulation (PBM), advanced platelet-rich fibrin (A-PRF), and Leukocyte and platelet-rich fibrin (L-PRF) for the management of medication-related osteonecrosis of the jaw (MRONJ).

Methods

Sixty rats underwent injection of zoledronate followed by left mandibular first and second molar extractions to induce MRONJ lesions. All rats were examined for the signs of MRONJ 8 weeks post-dental extraction. Forty-nine rats with positive signs of MRONJ were appointed to seven different groups as follows: control (Ctrl); surgery alone (Surg); surgery and PBM (Surg + PBM); surgery and A-PRF insertion (Surg + APRF); surgery and L-PRF insertion (Surg + LPRF); surgery, A-PRF insertion, and PBM (Surg + APRF + PBM); surgery, L-PRF insertion, and PBM (Surg + LPRF + PBM). Euthanasia was carried out 30 days after the last treatment session. The lesions' healing was evaluated clinically, histologically, and radiographically. Data were analyzed using STATA software version 14, and the statistical significance level was set at 5% for all cases.

Results

According to the present study, A-PRF and L-PRF treatment resulted in significant improvements in clinical, histological, and radiographical parameters compared to the Ctrl group (P < 0.05). The PBM also decreased wound dimensions and the number of empty lacunae compared to the Ctrl group (P < 0.05). Surg + APRF + PBM and Surg + LPRF + PBM were the only groups that presented a significantly higher mean number of osteocytes (P < 0.05). No significant differences were observed between A-PRF and L-PRF treatment groups (P > 0.05).

Conclusions

Surgical resection followed by applying A-PRF or L-PRF reinforced by PBM showed optimal wound healing and bone regeneration in MRONJ lesions.

Free Skin Grafting to Reconstruct Donor Sites after Radial Forearm Flap Harvesting: A Prospective Study with Platelet-Rich Fibrin (PRF)

Reconstruction of the donor site after radial forearm flap harvesting is a common procedure in maxillofacial plastic surgery. It is normally carried out with split-thickness or full-thickness free skin grafts. Unfortunately, free skin graft transplantation faces wound healing impairments such as necrosis, (partial) graft loss, or tendon exposure. Several studies have investigated methods to reduce these impairments and demonstrated improvements if the wound bed is optimised, for example, through negative-pressure wound therapy or vacuum-assisted closure. However, these methods are device-dependent, expansive, and time-consuming. Therefore, the application of platelet-rich fibrin (PRF) to the wound bed could be a simple, cost-effective, and device-independent method to optimise wound-bed conditions instead. In this study, PRF membranes were applied between the wound bed and skin graft. Results of this study indicate improvements in the PRF versus non-PRF group (93.44% versus 86.96% graft survival, p = 0.0292). PRF applied to the wound bed increases graft survival and reduces impairments. A possible explanation for this is the release of growth factors, which stimulate angiogenesis and fibroblast migration. Furthermore, the solid PRF membranes act as a mechanical barrier ("lubrication" layer) to protect the skin graft from tendon motion. The results of this study support the application of PRF in donor-site reconstruction with free skin grafts.

Comparison of the effects of platelet concentrates produced by high and low-speed centrifugation protocols on the healing of critical-size defects in rat calvaria: a microtomographic and histomorphometric study

The current study evaluated the healing of critical-size defects (CSD) created in rat calvaria treated with platelet concentrates produced by high-speed (Leukocyte- and Platelet-Rich Fibrin - L-PRF) and low-speed (Advanced Platelet-Rich Fibrin - A-PRF) protocols of centrifugation. Twenty-four rats were distributed into three groups: Control, L-PRF, and A-PRF. Five mm diameter CSD were created on the animals' calvaria. The defects of the L-PRF and A-PRF groups were filled with 0.01 ml of L-PRF and A-PRF, respectively. The control group defects were filled with a blood clot only. All animals were euthanized on the 35th postoperative day. Histomorphometric and microtomographic analyses were then performed. The L-PRF and A-PRF groups had significantly higher bone volume and neoformed bone area than those of the control group and lowered bone porosity values (p < .05). No significant differences were observed between A-PRF and L-PRF groups for the analyzed parameters. Therefore, it can be concluded that i) L-PRF and A-PRF potentiated the healing of CSD in rat calvaria; ii) high and low-speed centrifugation protocols did not produce PRF matrices with different biological impacts on the amount of bone neoformation.

Overview of the Effect of Different Regenerative Materials in Class II Furcation Defects in Periodontal Patients

The aim of this review was to give an overview of the outcomes of the use of different regenerative materials to treat molars with class II furcation defects in patients with periodontitis in comparison with open flap debridement (OFD). A search of five databases (PubMed-Medline, Embase, Cochrane, Scopus and Web of Science) was conducted up to and including January 2022. According to the PICOS guidelines, only randomized control trials (S) considering periodontal patients with at least one molar with a class II furcation involvement (P) treated with regenerative materials (I) in comparison to OFD as control treatment (C) and a minimum follow-up period of 6 months were included. Vertical clinical attachment level (VCAL) was considered as the primary outcome (O), while horizontal clinical attachment level (HCAL), horizontal probing depth (HPD) and vertical probing depth (VPD) were considered as secondary outcomes. The search through the databases initially identified 1315 articles. Only 25 of them met the eligibility criteria and were included. The studies were grouped in four macro-categories according to the material used: absorbable and non-absorbable membranes, blood derivatives and a combination of different materials. The greater part of the included studies reported a statistically significant difference in using regenerative materials when compared to OFD. The blood derivatives groups reported a range of mean changes in VCAL of 0.86-4.6 mm, absorbable membrane groups reported -0.6-3.75 mm, non-absorbable membranes groups reported -2.47-4.1 mm, multiple materials groups reported -1.5-4.87 mm and enamel matrix derivatives reported a mean change in VCAL of 1.45 mm. OFD showed a range of mean VCAL changes of -1.86-2.81 mm. Although no statistical analysis was performed, the use of regenerative materials may be considered moderately beneficial in the treatment of molars with grade II furcation involvement. However, the substantial heterogeneity in the protocols' design does not allow us to draw definitive conclusions. In addition, low levels of evidence for morbidity and patient-centered outcomes were reported.

Recession width evaluation after the use of Advanced PRF (A-PRF) verus subepithilial conncective tissue graft (SCTG) in combination with coronally advanced flap in treatment of gingival recession

Objective: To evaluate the amount of recession width following the use CAF and advanced platelet rich fibrin (A-PRF) compared to CAF with SCTG in the treatment of single gingival recession. Materials and Methods: Twenty gingival recession defects were randomly assigned to receive either CAF+SCTG (n=10) or CAF+A-PRF (n=10). Recession width in mm was assessed at 3, 6 and 9 months post-operatively. Results: Patients in test group (CAF+A-PRF) reported 2.13 ± 0.35 recession width at 3 months, 2.00 ± 0 after 6 months. While, finally decreased to 1.25±1.04 after 9 months. In the control group (CAF+SCTG), the amount of recession width recorded 1.00 ± 1.07 at 3 months, while, after 6 and 9 months decreased to 0.5 ± 0.93. Conclusion and recommendation: There was no statistically significant difference between the two studied groups after 9 months. While, A significant difference reported at 3 and 6 months. Further studies with larger sample size and longer follow-up is needed.

Changes in Migratory Speed Rate of Human Dental Pulp Stromal Cells Cultured in Advanced Platelet-Rich Fibrin

OBJECTIVE

 Migratory speed rate evaluation of human dental pulp stromal cells (hDP-SCs) is one of the important steps in dental pulp regeneration. Therefore, the aim of the study is to analyze various concentrations of advanced platelet-rich fibrin (A-PRF) culture media toward hDP-SCs' migratory speed rate evaluations.

MATERIALS AND METHODS

 The hDP-SCs were divided into four groups: control: hDP-SCs in Dulbecco's modified Eagle medium + 10% fetal bovine serum group; hDP-SCs in 1% A-PRF group; hDP-SCs in 5% A-PRF group; and hDP-SCs in 10% A-PRF group, which were planted in 24-well (5 × 10⁴ cell/well). The migratory speed rate of all groups was measured by using cell migration assay (scratch wound assay) after 24 hours. Cell characteristics were evaluated under microscope (Inverted microscope, Zeiss, Observer Z1, UK) that can be read through image-J interpretation. This image J represented the measurement of migratory speed rate (nm/h) data. Statistical analysis was conducted using one-way analysis of variance and post hoc Tamhane's test (p < 0.05) (IBM SPSS Statistics Software, version 22.0).

RESULTS

 There was a statistically significant difference in the migratory speed rates of hDP-SCs among various concentration groups of A-PRF (1, 5, and 10%) compared with the control group.

CONCLUSION

The increase in the migratory speed rate of hDP-SCs was highest in 10% A-PRF group.

Production Protocol Standardisation, Macroscopic and Histological Evaluation, and Growth Factor Quantification of Canine Leukocyte-and Platelet-Rich Fibrin Membranes

Leukocyte-Platelet-Rich Fibrin (L-PRF) is a second generation of platelet concentrates; it was widely used, as an autologous platelet-based wound sealant and hemostatic agent in surgical wound healing. L-PRF clot or membrane is a solid fibrin-based biomaterial, with a specific 3D distribution of the leukocytes and platelet aggregates. This biological scaffold releases growth factors (i.e., TGF- β1, PDGF-AB, VEGF) and matrix proteins (fibronectin, vitronectin and thrombospondin-1) during the healing process after the application. To the Authors' knowledge both in human and veterinary medicine a single standardised protocol was not reported. This prospective study aimed to apply Crisci's L-PRF protocol (which is characterised by 30” of acceleration, 2' at 2,700 rpm, 4' at 2,400 rpm, 3' at 3,000 rpm, and 36” of deceleration and arrest) sin canine species, evaluate macroscopically and histologically the L-PRF membranes obtained by using Wound Box to standardise the L-PRF protocol in dogs and to evaluate the clinical feasibility of using L-PRF membranes by quantitative in vitro analysis of growth factors over 7 days. One hundred twenty-eight dogs in good general condition with no history of recent NSAIDs intake (15 days of washout) and/or any medication or disease related to coagulation process met inclusion criteria and therefore were enrolled. We obtained 172 membrane L-PRF membranes by 86 dogs: half of them underwent macroscopic and histological analysis, the other 86 underwent ELISA analysis. The Wound Box gave a membrane of mean (±SD) length (cm), width (cm) and weight (g) of 1.97 (±0.89), 0.95 (±0.36), 0.46 (±0.20) respectively. Histology analysis confirmed a well-defined histoarchitecture with five layers reproducing density and distribution of blood cells in this biomaterial. Finally, the ELISA assay performed with 22 L-PRF membranes showed a peak in growth factors at 6 h after membrane production, followed by a decrease in release at 24 and 72 h and a second peak in release at 168 h after production. Statistical analysis of demographic variables (age, sex, and body condition score BCS) and the average of growth factors determined by the ELISA assay did not reveal statistical significance, except for the BCS factor compared with the production of VEGF. Our data confirm the effectiveness of this protocol and of Wound Box to produce L-PRF membranes in dogs.

Tensile Strength Essay Comparing Three Different Platelet-Rich Fibrin Membranes (L-PRF, A-PRF, and A-PRF+): A Mechanical and Structural In Vitro Evaluation

Predictable outcomes intended by the application of PRF (platelet-rich fibrin) derivative membranes have created a lack of consideration for their consistency and functional integrity. This study aimed to compare the mechanical properties through tensile strength and analyze the structural organization among the membranes produced by L-PRF (leukocyte platelet-rich fibrin), A-PRF (advanced platelet-rich fibrin), and A-PRF+ (advanced platelet-rich fibrin plus) (original protocols) that varied in centrifugation speed and time. L-PRF (n = 12), A-PRF (n = 19), and A-PRF+ (n = 13) membranes were submitted to a traction test, evaluating the maximum and average traction. For maximum traction, 0.0020, 0.0022, and 0.0010 N·mm−2 were obtained for A-PRF, A-PRF+, and L-PRF, respectively; regarding the average resistance to traction, 0.0012, 0.0015, and 0.006 N·mm−2 were obtained, respectively (A-PRF+ > A-PRF > L-PRF). For all groups studied, significant results were found. In the surface morphology observations through SEM, the L-PRF matrix showed a highly compact surface with thick fibers present within interfibrous areas with the apparent destruction of red blood cells and leukocytes. The A-PRF protocol showed a dense matrix composed of thin and elongated fibers that seemed to follow a preferential and orientated direction in which the platelets were well-adhered. Porosity was also evident with a large diameter of the interfibrous spaces whereas A-PRF+ was the most porous platelet concentrate with the greatest fiber abundance and cell preservation. Thus, this study concluded that A-PRF+ produced membranes with significant and higher maximum traction results, indicating a better viscoelastic strength when stretched by two opposing forces.

Tranexamic acid integrated into platelet-rich fibrin produces a robust and resilient antihemorrhagic biological agent: a human cohort study

OBJECTIVE

To investigate the incorporation of the antifibrinolytic agent tranexamic acid (TA) during platelet-rich fibrin (PRF) formation to produce a robust fibrin agent with procoagulation properties.

STUDY DESIGN

Blood from healthy volunteers was collected. Into 3 tubes, TA was immediately added in 1-mL, 0.4-mL, and 0.2-mL volumes, and the fourth tube was without additions. After PRF preparation, the clots were weighed in their raw (clot) and membrane forms. PRF physical properties were analyzed using a universal testing system (Instron). Protein and TA levels in the PRF were analyzed using a bicinchoninic acid assay and a ferric chloride assay, respectively.

RESULTS

The addition of TA to PRF led to a robust weight compared with sham control. PRF weight was greater in females in all tested groups. The addition of TA also led to greater resilience to tears, especially at 1-mL TA addition to the blood. Furthermore, TA addition led to a greater value of total protein within the PRF and entrapment of TA in the PRF.

CONCLUSIONS

Addition of TA to a PRF preparation leads to robust PRF with greater protein levels and the amalgamation of TA into the PRF. Such an agent may enhance the beneficial properties of PRF and attribute procoagulation properties to it.