Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part IV: clinical effects on tissue healing

Bone tissue engineering with bone marrow-derived stromal cells integrated with concentrated growth factor in Rattus norvegicus calvaria defect model

Concentrated growth factor (CGF) is an autologous leukocyte-rich and platelet-rich fibrin (L-PRF) biomaterial termed "second-generation platelet concentrate". CGF contains autologous osteoinductive platelet growth factors and an osteoconductive fibrin matrix. The purpose of this study was to assess the ability of CGF combined with bone marrow stromal cells (BMSCs) to heal critical-size rat calvaria defects in vivo and to modulate the proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro. In the in-vivo study, the CGF group regenerated bone better than the control group, and combined therapy with CGF and BMSCs almost completely repaired critical-size bone defects within 12 weeks after surgery. In the in-vitro study, the CGF extract, at concentrations between 1 and 10%, promoted proliferation, osteogenic maturation, and mineralization of hTERT-E6/E7 human MSCs in a dose-dependent manner but had an inhibitory effect at higher concentrations. In conclusion, a CGF extract promoted the proliferation, osteogenic maturation, and mineralization of mesenchymal stem cells in vitro, and combination therapy with CGF and BMSCs resulted in excellent healing of critical-size bone defects in vivo.

Combination of platelet rich fibrin, hydroxyapatite and PRF membrane in the management of large inflammatory periapical lesion

Periapical inflammatory lesion is the local response of bone around the apex of tooth that develops after the necrosis of the pulp tissue or extensive periodontal disease. The final outcome of the nature of wound healing after endodontic surgery can be repair or regeneration depending on the nature of the wound; the availability of progenitor cells; signaling molecules; and micro-environmental cues such as adhesion molecules, extracellular matrix, and associated non-collagenous protein molecules. The purpose of this case report is to add knowledge to the existing literature about the combined use of graft material [platelet rich fibrin (PRF) and hydroxyapatite (HA)] and barrier membrane in the treatment of large periapical lesion. A periapical endodontic surgery was performed on a 45 year old male patient with a swelling in the upper front teeth region and a large bony defect radiologically. The surgical defect was filled with a combination of PRF and HA bone graft crystals. The defect was covered by PRF membrane and sutured. Clinical examination revealed uneventful wound healing. Radiologically the HA crystals have been completely replaced by new bone at the end of 2 years. On the basis of the results obtained in our case report, we hypothesize that the use of PRF in conjunction with HA crystals might have accelerated the resorption of the graft crystals and would have induced the rapid rate of bone formation.

A new biological approach to guided bone and tissue regeneration

The purpose of this study was to determine the potential of platelet-rich fibrin (PRF) membranes used for guided bone and tissue regeneration. A patient with insufficient alveolar ridge width in aesthetic zone was enrolled. The patient's blood was centrifuged to obtain PRF membranes. Autogenous bone graft was mixed with bovine hydroxyapatite, PRF particles and applied to fill the defect. Five PRF membranes were placed over the bone mix. After 4 months a cone-beam CT was performed to evaluate bone regeneration. The use of PRF as cover membrane permitted a rapid epithelisation and represented an effective barrier versus epithelial cell penetration. After 4 months the site appeared precociously healed and the bone volume increased. This new approach represents a predictable method of augmenting deficient alveolar ridges. Guided bone regeneration with PRF showed limitation compared with guided bone regeneration using collagen membrane in terms of bone gain. The association of collagen membrane and PRF could be a good association.

Prevention of localized osteitis in mandibular third-molar sites using platelet-rich fibrin

Purpose. To review our experience utilizing platelet rich fibrin (PRF), which is reported to aid in wound healing of extraction sites, for the prevention of localized osteitis following lower third-molar removal. Materials and Methods. PRF was placed in the mandibular third-molar extraction sites, 200 sites total, on 100 consecutive patients treated in our practice, by the authors. The patients were managed with standard surgical techniques, intraoperative IV antibiotic/steroid coverage, and routine postoperative narcotic analgesics/short-term steroid coverage. All patients were reevaluated for localized osteitis within 7-10 days of the surgery. A comparison group consisted of 100 consecutive patients who underwent bilateral removal of indicated mandibular wisdom teeth and did not receive PRF placement within the lower third molar surgical sites. Results. The incidence of localized osteitis (LO) following removal of 200 lower third molars with simultaneous PRF placement within the extraction site was 1% (2 sites out of 200). The group of patients whose mandibular 3rd molar sockets were not treated with PRF demonstrated a 9.5% (19 sites out of 200) incidence of localized osteitis. The latter group also required 6.5 hours of additional clinical time to manage LO than the study group who received PRF. Conclusions. This retrospective review demonstrated that preventative treatment of localized osteitis can be accomplished using a low cost, autogenous, soluble, biologic material, PRF, that PRF enhanced third-molar socket healing/clot retention and greatly decreased the clinical time required for postoperative management of LO.

Platelet-rich fibrin promotes periodontal regeneration and enhances alveolar bone augmentation

In the present study we have determined the suitability of platelet-rich fibrin (PRF) as a complex scaffold for periodontal tissue regeneration. Replacing PRF with its major component fibrin increased mineralization in alveolar bone progenitors when compared to periodontal progenitors, suggesting that fibrin played a substantial role in PRF-induced osteogenic lineage differentiation. Moreover, there was a 3.6-fold increase in the early osteoblast transcription factor RUNX2 and a 3.1-fold reduction of the mineralization inhibitor MGP as a result of PRF application in alveolar bone progenitors, a trend not observed in periodontal progenitors. Subcutaneous implantation studies revealed that PRF readily integrated with surrounding tissues and was partially replaced with collagen fibers 2 weeks after implantation. Finally, clinical pilot studies in human patients documented an approximately 5 mm elevation of alveolar bone height in tandem with oral mucosal wound healing. Together, these studies suggest that PRF enhances osteogenic lineage differentiation of alveolar bone progenitors more than of periodontal progenitors by augmenting osteoblast differentiation, RUNX2 expression, and mineralized nodule formation via its principal component fibrin. They also document that PRF functions as a complex regenerative scaffold promoting both tissue-specific alveolar bone augmentation and surrounding periodontal soft tissue regeneration via progenitor-specific mechanisms.

Platelet-Rich fibrin: A second generation platelet concentrate and a new friend of oral and maxillofacial surgeons

To assess the potential use and benefits of Platelet-Rich Fibrin (PRF) over Platelet-Rich Plasma (PRP), for wound healing post oral and maxillofacial surgeries. This article describes the evolution of this second generation platelet concentrate and its multiple uses in various surgical procedures. Around 5 ml of whole venous blood is collected from the patients in each of the two sterile vacutainer tubes of 6 ml capacity without anticoagulant. The vacutainer tubes are then placed in a centrifugal machine at 3000 revolutions per minute (rpm) for 10 minutes, and the middle fraction containing the fibrin clot is then collected 2 mm below lower dividing line, to obtain the PRF. Cavities filled with PRF post oral and maxillofacial surgical procedures, at the institute, showed faster healing in half the time as compared to physiologic healing. PRF, which belongs to a new second generation of platelet concentrates, with simplified processing, and not requiring biochemical blood handling, has several advantages over traditionally prepared PRP, which has been widely used for accelerating soft tissue and hard tissue healing. However, the preparation being strictly autologous, the amount of PRF obtained is limited.

Efficacy of leukocyte- and platelet-rich fibrin in wound healing: a randomized controlled clinical trial

BACKGROUND

Application of platelet concentrates to wounds could speed healing. Leukocyte- and platelet-rich fibrin, a relatively recent development, stands out from the other preparations. This prospective, randomized, controlled clinical trial studied the rate of healing of postoperative hand wounds after a single application of leukocyte- and platelet-rich fibrin.

METHODS

Eligible patients were healthy individuals older than 18 years who had been scheduled for elective McCash (open palm) surgery for Dupuytren disease at the Plastic and Hand Surgery Department of Nice's University Hospital between August of 2007 and February of 2010. The control group received the reference care of petroleum jelly mesh (Vaselitulle), and test patients had leukocyte- and platelet-rich fibrin applied. The primary endpoint was healing delay measured in postoperative days. Secondary endpoints included pain, bleeding, and wound exudate. The trial was carried out as a single-blind trial.

RESULTS

Among the 68 randomized patients, 33 patients in the leukocyte- and platelet-rich fibrin group and 31 in the Vaselitulle group were analyzed. Primary endpoint analysis showed a median healing delay of 24 days (interquartile range, 18 to 28 days) for the fibrin group and 29 days (interquartile range, 26 to 35 days) for the Vaselitulle group (p = 0.014, log-rank test). Postoperative pain assessment, bleeding, and exudate were always lower for the fibrin group, but not significantly so.

CONCLUSION

The authors trial demonstrates that a single leukocyte- and platelet-rich fibrin application on fresh postoperative hand wounds shows a median improvement of 5 days in comparison with the standard treatment.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Comparative evaluation of autologous platelet-rich fibrin and platelet-rich plasma in the treatment of mandibular degree II furcation defects: a randomized controlled clinical trial

BACKGROUND

The treatment of molar furcation defects remains a considerable challenge in clinical practice. The identification of clinical measurements influential to treatment outcomes is critical to optimize the results of surgical periodontal therapy. The present study aimed to explore the clinical and radiographical effectiveness of autologous platelet-rich fibrin (PRF) and autologous platelet-rich plasma (PRP) in the treatment of mandibular degree II furcation defects in subjects with chronic periodontitis.

MATERIAL AND METHODS

Seventy-two mandibular degree II furcation defects were treated with either autologous PRF with open flap debridement (OFD; 24 defects) or autologous PRP with OFD (25), or OFD alone (23). Clinical and radiological parameters such as probing depth, relative vertical clinical attachment level and horizontal clinical attachment level along with gingival marginal level were recorded at baseline and 9 mo postoperatively.

RESULTS

All clinical and radiographic parameters showed statistically significant improvement at both the test sites (PRF with OFD and PRP with OFD) compared to those with OFD alone. Relative vertical clinical attachment level gain was also greater in PRF (2.87 ± 0.85 mm) and PRP (2.71 ± 1.04 mm) sites as compared to control site (1.37 ± 0.58 mm), and relative horizontal clinical attachment level gain was statistically significantly greater in both PRF and PRP than in the control group.

CONCLUSIONS

The use of autologous PRF or PRP were both effective in the treatment of furcation defects with uneventful healing of sites.

A novel approach for treatment of an unusual presentation of radicular cysts using autologous periosteum and platelet-rich fibrin in combination with demineralized freeze-dried bone allograft

Radicular cysts are the most common cystic lesions affecting the jaws. They are most commonly found at the apices of the involved teeth. This condition is usually asymptomatic but can result in a slow-growth tumefaction in the affected region. The following case report presents the successful treatment of radicular cysts using autologous periosteum and platelet-rich fibrin with demineralized freeze-dried bone allograft.

Clinical effectiveness of autologous platelet rich fibrin in the management of infrabony periodontal defects

BACKGROUND

This interventional controlled clinical trial with split mouth design compares the clinical effectiveness of autologous platelet rich fibrin with open flap debridement in the management of infrabony periodontal defects.

METHODS

Fifteen patients with paired contralateral infrabony defects were treated with open flap debridement and autologous platelet rich fibrin (experimental group) or open flap debridement alone (control group). The changes in probing pocket depth, clinical attachment level, and radiographic defect depth were evaluated. Patient perception regarding pain and discomfort following the procedures and early soft tissue healing responses were assessed by visual analog scales, scored 7 days after the surgical procedures. Final reevaluation was done 1 year after surgery.

RESULTS

Baseline clinical and radiographic measurements were comparable between the groups. Reevaluation at 1 year revealed that both treatment modalities resulted in a significant decrease in probing pocket depth, gain in clinical attachment and radiographic bone fill of the defects compared to baseline. Postoperative differences observed between the two groups were 2.27±0.29mm (P<0.001) for probing pocket depth, 3.33±0.35mm (P<0.001) for clinical attachment level and 1.29±0.32mm (P<0.001) for radiographic infrabony defect depth reduction, all in favor of the experimental group. Patient preference was greater and early healing response better for the experimental group as assessed by the visual analog scores.

CONCLUSION

Within the limitations of this study it can be concluded that use of platelet rich fibrin is more effective than open flap debridement alone in the management of infrabony periodontal defects.

Role of platelet-rich-fibrin in enhancing palatal wound healing after free graft

Platelet-rich fibrin has long been used as a wound healing therapy in skin wounds and recently evidence has suggested its usage in oral cavity for different treatment procedures. This article proposes an overview of use of platelet-rich fibrin in management of complicated oral wounds. Excessive hemorrhage of the donor area, necrosis of epithelium, and morbidity associated with donor site have been described as the possible complications after harvesting subepithelial connective tissue graft, but little has been mentioned about their management. The article includes a case report of a 45-year-old male patient who showed a delayed wound healing after subepithelial connective tissue graft harvestation, which was treated with platelet-rich fibrin.

Platelet rich fibrin: a new paradigm in periodontal regeneration

Among the great challenges facing clinical research is the development of bioactive surgical additives regulating inflammation and increasing healing. Although the use of fibrin adhesives and platelet-rich plasma (PRP) is well documented, they have their own limitations. Hence, reconstructive dental surgeons are looking for an "edge" that jump starts the healing process to maximize predictability as well as the volume of regenerated bone. Overcoming the restrictions related to the reimplantation of blood-derived products, a new family of platelet concentrate, which is neither a fibrin glue nor a classical platelet concentrate, was developed in France. This second generation platelet concentrate called platelet-rich fibrin (PRF), has been widely used to accelerate soft and hard tissue healing. Its advantages over the better known PRP include ease of preparation/application, minimal expense, and lack of biochemical modification (no bovine thrombin or anticoagulant is required). This article serves as an introduction to the PRF "concept" and its potential clinical applications with emphasis on periodontal regeneration.

One-step apexification in immature tooth using grey mineral trioxide aggregate as an apical barrier and autologus platelet rich fibrin membrane as an internal matrix

Immature teeth with necrotic pulp and periapical lesion are difficult to treat via conventional endodontic therapy. Numerous procedures and materials have been utilized to induce root-end barrier formation. Traditionally, calcium hydroxide has been the material of choice for the apexification of immature permanent teeth; however, Mineral Trioxide Aggregate holds significant promise as an alternative to multiple treatments with calcium hydroxide. One of the technical problems associated with the placement of the restorative materials used as artificial barrier is to prevent overfill and underfill. Using a matrix avoids the extrusion of the material into the periodontal tissues. This case report presents the successful healing and apexification with combined use of Mineral Trioxide Aggregate as an apical barrier, and autologus platelet rich fibrin membrane as an internal matrix.

In vivo evaluation of titanium-prepared platelet-rich fibrin (T-PRF): a new platelet concentrate

We have developed a new, titanium-prepared, platelet-rich fibrin (T-PRF) together with the protocol for forming it, which is based on the hypothesis that titanium tubes may be more effective at activating platelets than the glass tubes used by Chouckroun in his platelet-rich fibrin (PRF) method. The aim of this study was to find a suitable animal model in which to evaluate the method and to investigate the efficacy of T-PRF for wound healing. Blood samples from 6 rabbits were used to confirm the protocol for formation of T-PRF. We evaluated T-PRF or T-PRF-like clots morphologically using scanning electron microscopy (EM). Blood samples from 5 rabbits were used to develop an experiment in which to evaluate the effects of T-PRF on wound healing. The mucoperiosteal flaps were filled with autologous T-PRF membranes from the vestibule in the anterior mandibular regions. Samples collected from the surgical sites were stained with haematoxylin and eosin. We found a mature fibrin network in T-PRF clots that had been centrifuged for 15 min at 3500 rpm and, 15 days after placement of the membrane, we found newly-forming connective tissue and islets of bony tissue in the T-PRF membrane. These results show that T-PRF could induce the formation of new bone with new connective tissue in a rabbit model of wound healing within 30 days of treatment.

Biochemical, mechanical, and morphological properties of a completely autologous platelet-rich wound sealant

The optimal composition of fibrin sealant preparations is not known. We, therefore, sought to construct a series of sealants from autologous components and compare their functioning to Bioseal a commonly used sealant. Characteristics of the platelet-rich plasma, cryoprecipitate, and thrombin were determined and compared to commercial glue from composition, function, and microscopy aspects. The concentrations of platelets as well as fibronectin in autologous fibrin glues were significantly higher than those in commercial ones (P < 0.001). Mechanical values (maximum amplitude and clot strength) obtained from thrombelastograph assays in two groups were not significantly different (P > 0.05). A dense platelet surface and fibrin net structures could be observed in the autologous samples, whereas there were only sparse fibrin nets without cellular components in Bioseal. Characterization of autologous and Bioseal fibrin sealants and their performance do not have significant difference in biochemical and mechanical properties. The entirely autologous platelet-rich gel in the present study may get wide application in future practice after confirmation of its safety, efficiency, and economic benefits.

Use of platelet-rich fibrin and platelet-rich plasma in combination with fat graft: which is more effective during facial lipostructure?

PURPOSE

Fat grafts have always represented a challenge in inducing the necessary neoangiogenesis, which results in significant resorption. This study was designed to compare the efficiency of first- and second-generation platelet-rich plasmas (PRPs) combined with a fat graft during facial lipostructure surgery.

METHODS AND MATERIALS

To address the research purpose, the investigators designed and implemented a double-blinded prospective clinical trial. The patients underwent bilateral facial lipostructure, a natural long-lasting method of filling and supporting the face using intricate layers of infiltrated autologous fat. The method involved the use of PRP on 1 side and platelet-rich fibrin (PRF) on the other side. The study population was composed of all patients presenting to the authors' department for the evaluation and management of facial contouring in the cheek and cheekbone areas from June 2008 through December 2010. The primary predictor variable was the type of combination (PRP/fat or PRF/fat). The outcome variables were the amount of resorption, which was estimated by comparing pre- and postsurgical photographic views, pain, edema, and bruising. The statistical evaluation of the findings was performed using SPSS software. Parametric tests (t test and Levene test) were used to compare the treatment efficacy and complications between the groups.

RESULTS

Twenty-five patients (8 men and 17 women) underwent bilateral facial lipostructure surgery in the cheek and cheekbone areas using PRP and PRF. One year after the operation, a slight esthetic asymmetry was noticeable, with greater average resorption on the PRP/fat side.

CONCLUSIONS

This first comparative clinical study highlights the value of using concentrated platelets for adipocyte grafts. The results suggest that the combination of fat and PRF is more effective than the combination of fat and PRP in the context of facial lipostructure surgery.

Use of autologous platelet rich fibrin in urethracutaneous fistula repair: preliminary report

Urethrocutaneous fistula (UCF) is one of the most common complications occurring after hypospadias repair. Despite the surgical advancement in hypospadias, multiple failed fistula closures are commonly referred to paediatric urologists. Although several techniques have been described to interpose a waterproof layer between urethral and skin closures, occurrence of urethrocutaneous fistula cannot be eliminated completely. In addition to several local tissue grafts, autologous and homologous fibrin sealants are used to prevent UCF. Platelet rich fibrin (PRF) is known as an autologous source of growth factors obtained from the sera of the patient. PRF supports collagen synthesis and tissue repair and accelerates wound healing. We aimed to present our initial experience about the use of autologous PRF in a 3-year-old boy with a UCF after hypospadias repair.

Postextraction osteotome sinus floor elevation technique using plasma-rich growth factors

PURPOSE

To evaluate a modified osteotome sinus floor elevation technique with immediate postextraction implant placement and the adjunct of a platelet-derived fibrin plug for the rehabilitation of maxillary premolar sites.

MATERIAL AND METHODS

Fifteen patients with nonrestorable fractured endodontically treated maxillary premolars were consecutively enrolled in the study. After extraction, the membrane was gradually elevated using osteotomes, with the interposition of a fibrin clot. Subsequently, an implant embedded with plasma very rich in growth factors was inserted.

RESULTS

No implant failed after a mean follow-up of 35 months. The average membrane lift was 2.9 ± 0.8 mm. After 1 year of loading, marginal bone loss averaged 0.36 ± 0.19 mm. No postoperative symptoms were reported. All patients reported full satisfaction for mastication function, phonetics, and aesthetics.

CONCLUSIONS

The present technique represents a viable option for the rehabilitation of fresh postextraction maxillary premolar sockets.

Platelet rich fibrin: a novel approach for osseous regeneration

 : To evaluate the efficacy of autologous platelet rich fibrin in soft tissue healing and bone regeneration in mandibular third molar extraction sockets.

METHOD

The study was conducted in 20 patients visiting in outpatient department of Oral and Maxillofacial Surgery, requiring extraction of bilateral mandibular third molar, following extraction platelet rich fibrin (PRF) was placed in one extraction sockets, the other socket was studied as the control sites with no PRF. The patient were assessed for post operative pain, soft tissue healing and trabecular pattern in healing bone. Radiological assessment of the extraction site was done for period of 3 months to evaluate the change in bone density.

RESULTS

Pain was less in study side compare to control site soft tissue was healing was better in study site. Evaluation of trabecular bone formation started earlier in PRF site compare to control site. The evaluation of bone density by radiological assessment showed the grey level value calculated after 3 months at the PRF site well comparatively higher than the average baseline value of the bone density at the extraction site in control site.

CONCLUSION

The study showed that autologous PRF is biocompatible and has significantly improved soft tissue healing. Bone regeneration and increase in bone density in extraction sockets. However, a more elaborate study with a large number of clinical cases is essential to be more conclusive regarding its efficacy.

Bone regeneration in the maxillary sinus using an autologous fibrin-rich block with concentrated growth factors alone

PURPOSE

The purpose of this study was to evaluate the predictability of new bone formation in the maxillary sinus using an autologous fibrin-rich blocks with concentrated growth factors (CGFs) alone as an alternative to graft material.

MATERIALS AND METHODS

A total of sixty-one sinus grafts were consecutively performed using the lateral window approach. After making replaceable bony window, the sinus membrane was elevated to make a new compartment. After 113 implants (average 13 mm high) with 11 different systems were placed simultaneously, the collected fibrin-rich blocks with CGFs alone were inserted in the sinus. To seal the lateral window, the bony window was repositioned. Radiographic, clinical, and histologic evaluation was performed to verify sinus augmentation.

RESULTS

No significant postoperative complications developed. New bone consolidation in all augmented maxillary sinus was observed along the implants on plain radiographs and on cone-beam computed tomograms. The success rate of implant was 98.2% after an average of 10 months loading.

CONCLUSION

Fibrin-rich blocks with CGFs act as an alternative to bone grafting and can be a predictable procedure for sinus augmentation.

Platelet-rich fibrin and piezoelectric surgery: a safe technique for the prevention of periodontal complications in third molar surgery

PURPOSE

The surgical removal of impacted mesioangular mandibular third molars (3Ms) may produce trauma to the soft tissues and bony structures. In particular, healing of postextractive socket may cause periodontal defects at the distal root of the second molar. The aim of the present prospective study was to assess the outcomes of a surgical protocol to remove 3Ms including the use of ultrasound bone surgery devices and platelet-rich fibrin (PRF) as a grafting material.

PATIENTS AND METHODS

Twenty-eight impacted mandibular 3Ms were removed. Fourteen 3Ms were removed by piezoelectric osteotomy and PRF application. Instead, the 14 3Ms of the control group were removed by piezoelectric osteotomy but without PRF application. Probing depth in the distal position for all the mandibular second molars was registered before and 6 months after surgery.

RESULTS

No complications were encountered. In the study group, alveolar socket fulfillment was rated as sufficient in 4 cases and adequate in the remaining 10 cases, whereas in the control group, it was rated as insufficient in 3 cases, sufficient in 4 cases, and adequate in 7 cases. Mean preoperative periodontal probing in the control group was 3.78 mm, whereas in the study group, it was 3.93 mm.Six months after surgery, mean periodontal probing was 3.28 mm in the control group and 3.07 mm in the study group.

CONCLUSIONS

Combined action of PRF and piezoelectric surgery can be considered a safe and fine technique for third molar surgery and alveolar socket healing.

Fibrin glue as the cell-delivery vehicle for mesenchymal stromal cells in regenerative medicine

The use of tissue-engineering techniques such as stem-cell therapy to renew injured tissues is a promising strategy in regenerative medicine. As a cell-delivery vehicle, fibrin glues (FG) facilitate cell attachment, growth and differentiation and, ultimately, tissue formation and organization by its three-dimensional structure. Numerous studies have provided evidence that stromal cells derived from bone marrow (bone marrow stromal cells; BMSC) and adipose tissue (adipose-derived stromal cells; ADSC) contain a population of adult multipotent mesenchymal stromal cells (MSC) and endothelial progenitor cells that can differentiate into several lineages. By combining MSC with FG, the implantation could take advantage of the mutual benefits. Researchers and physicians have pinned their hopes on stem cells for developing novel approaches in regenerative medicine. This review focuses on the therapeutic potential of MSC with FG in bone defect reconstruction, cartilage and tendon injury repair, ligament, heart and nerve regeneration, and, furthermore, wound healing.

Platelet-rich fibrin and bovine porous bone mineral vs. platelet-rich fibrin in the treatment of intrabony periodontal defects

BACKGROUND AND OBJECTIVE

Bovine porous bone mineral (BPBM) is a xenograft that has been successfully utilized in periodontal regeneration. Platelet-rich fibrin (PRF) is a leukocyte and platelet preparation that concentrates various polypeptide growth factors and therefore has the potential to be used as regenerative treatment for periodontal defects. The purpose of this study was to examine the suitability of autologous PRF as regenerative treatment for periodontal intrabony defects in humans and to examine the ability of BPBM to augment the regenerative effects exerted by PRF.

MATERIAL AND METHODS

Using a split-mouth design, 17 paired intrabony defects were randomly treated either with PRF or with PRF-BPBM combination. Re-entry surgeries were performed at 6 mo. Primary study outcomes were changes in pocket depth, attachment level and defect fill.

RESULTS

Preoperative pocket depths, attachment levels and transoperative bone measurements were similar for the PRF and PRF-BPBM groups. Postsurgical measurements revealed a significantly greater reduction in pocket depth in the PRF-BPBM group (4.47±0.78 mm on buccal and 4.29±0.82 mm on lingual sites) when compared with the PRF group (3.35±0.68 mm on buccal and 3.24±0.73 mm on lingual sites). The PRF-BPBM group presented with significantly greater attachment gain (3.82±0.78 mm on buccal and 3.71±0.75 mm on lingual sites) than the PRF group (2.24±0.73 mm on buccal and 2.12±0.68 mm on lingual sites). Defect fill was also greater in the PRF-BPBM group (4.06±0.87 mm on buccal and 3.94±0.73 mm on lingual sites) than in the PRF group (2.21±0.68 mm on buccal and 2.06±0.64 mm on lingual sites).

CONCLUSION

The results of this study indicate that PRF can improve clinical parameters associated with human intrabony periodontal defects, and BPBM has the ability to augment the effects of PRF in reducing pocket depth, improving clinical attachment levels and promoting defect fill.

Growth factors, CD34 positive cells, and fibrin network analysis in concentrated growth factors fraction

An interesting clinical option for optimizing healing tissue is the use of platelet concentrate. Platelets contain high quantities of growth factors, among these TGF-β1 and VEGF, which are known to be implicated in tissue regeneration. CGF is produced by processing blood samples with a special centrifuge device; three layers are formed: top acellular plasma (PPP), middle CGF and bottom red blood cells (RBC) layers. Given that to date there are no data concerning the biological characteristic of CGF, the aim of this study was to evaluate the presence of TGF-β1 and VEGF in CGF and also in PPP and RBC layers. In addition, since circulating stem cells are recruited from blood to injured tissue for healing we also evaluated the presence of CD34 positive cells. Our data show the presence of TGF-β1 and VEGF in CGF and RBC layers. In addition, we show CD34 positive cells in CGF.

Effects of platelet-rich fibrin on human periodontal ligament fibroblasts and application for periodontal infrabony defects

BACKGROUND

Platelet-rich fibrin (PRF) by Choukroun's technique is derived from an autogenous preparation of concentrated platelets. Little is known about the effects of PRF on periodontal ligament fibroblasts (PDLFs) and the application of PRF for periodontal regeneration.

METHODS

PDLFs were derived from healthy individuals undergoing extraction for orthodontic reasons. Blood collection was carried out from healthy volunteers. PRF was obtained from a table centrifuge centrifuged at 3000 rpm for 12 minutes. The effects of PRF on PDLFs were determined by measuring the expression of phosphorylated extracellular signal-regulated protein kinase (p-ERK), osteoprotegerin (OPG) and alkaline phosphatase (ALP) activity. Moreover, we retrospectively examined the feasibility and safety of reconstructing the periodontal infrabony defects with PRF in six patients.

RESULTS

PRF was found to increase ERK phosphorylation and OPG in PDLFs in a time-dependent manner (p < 0.05). ALP activity was also significantly upregulated by PRF (p < 0.05). Application of PRF in infrabony defects exhibited pocket reduction and clinical attachment gain after six months. Periapical radiography revealed radiographic defect filled in grafted teeth.

CONCLUSIONS

The enhancement of p-ERK, OPG and ALP expression by PRF may provide benefits for periodontal regeneration. Clinical and radiologic analysis showed that the use of PRF is an effective modality for periodontal infrabony defects.

Prevention of hemorrhagic complications after dental extractions into open heart surgery patients under anticoagulant therapy: the use of leukocyte- and platelet-rich fibrin

Leukocyte- and platelet-rich fibrin (L-PRF) is a biomaterial commonly used in periodontology and implant dentistry to improve healing and tissue regeneration, particularly as filling material in alveolar sockets to regenerate bone for optimal dental implant placement. The objective of this work was to evaluate the use of L-PRF as a safe filling and hemostatic material after dental extractions (or avulsions) for the prevention of hemorrhagic complications in heart surgery patients without modification of the anticoagulant oral therapy. Fifty heart surgery patients under oral anticoagulant therapy who needed dental extractions were selected for the study. Patients were treated with L-PRF clots placed into 168 postextraction sockets without modification of anticoagulant therapy (mean international normalized ratio  =  3.16 ± 0.39). Only 2 patients reported hemorrhagic complications (4%), all of which resolved a few hours after the surgery by compression and hemostatic topical agents. Ten patients (20%) showed mild bleeding, which spontaneously resolved or was resolved by minimal compression less than 2 hours after surgery. No case of delayed bleeding was reported. The remaining 38 patients (76%) showed an adequate hemostasis after the dental extractions. In all cases, no alveolitis or painful events were reported, soft tissue healing was quick, and wound closure was always complete at the time of suture removal one week after surgery. The proposed protocol is a reliable therapeutic option to avoid significant bleeding after dental extractions without the suspension of the continuous oral anticoagulant therapy in heart surgery patients. Other applications of the hemostatic and healing properties of L-PRF should be investigated in oral implantology.

Simultaneous sinus-lift and implantation using microthreaded implants and leukocyte- and platelet-rich fibrin as sole grafting material: a six-year experience

PURPOSE

To assess the relevance of simultaneous sinus-lift and implantation with leukocyte- and platelet-rich fibrin (L-PRF, Choukroun's technique) as sole subsinus filling material.

MATERIALS

Twenty-three lateral sinus elevations (SA4 sinus) were performed on 20 patients with simultaneous implant placement. Seven patients were treated with 19 Astra implants (AstraTech, Mölndal, Sweden) and 13 patients with 33 Intra-Lock implants (Intra-Lock Ossean, Boca Raton, FL). L-PRF membranes were used to cover the Schneiderian membrane, the implant tips served as "tent pegs" for the L-PRF-patched sinus membranes, and the subsinus cavity was finally filled with L-PRF clots. Clinical and radiographic follow-up was performed just after implant placement, after 6 months, 1 year and each following year.

RESULTS

Six months after surgery, all implants were clinically stable during abutment tightening. The maximum follow-up was 6 years, and all patients were followed up for a minimum of 2 years. No implant was lost during this 6-year experience, and the vertical bone gain was always substantial, between 8.5 and 12 mm bone gain (10.4 ± 1.2). The final level of the new sinus floor was always in continuation with the implant apical end, and the periimplant crestal bone height was stable.

CONCLUSION

The use of L-PRF as sole filling material during simultaneous sinus-lift and implantation seems to be a reliable surgical option promoting natural bone regeneration.

Treatment of 3-wall intrabony defects in patients with chronic periodontitis with autologous platelet-rich fibrin: a randomized controlled clinical trial

BACKGROUND

Platelet-rich fibrin (PRF) is considered a second-generation platelet concentrate that is widely used in osseous regeneration. The present study aims to explore the clinical and radiographic effectiveness of autologous PRF in the treatment of intrabony defects in patients with chronic periodontitis.

METHODS

Fifty-six intrabony defects were treated with either autologous PRF with open-flap debridement or open-flap debridement alone. Clinical parameters such as the probing depth (PD) and periodontal attachment level (PAL) were recorded at baseline and 9 months postoperatively. The defect fill at baseline and 9 months was calculated on standardized radiographs by using image-analysis software.

RESULTS

The mean PD reduction was greater in the test group (4.55 ± 1.87 mm) than in the control group (3.21 ± 1.64 mm), whereas the mean PAL gain was also greater in the test group (3.31 ± 1.76) compared to the control group (2.77 ± 1.44 mm). Furthermore, a significantly greater percentage of mean bone fill was found in the test group (48.26% ± 5.72%) compared to the control group (1.80% ± 1.56%).

CONCLUSIONS

Within the limits of the present study, there was greater PD reduction, PAL gain, and bone fill at sites treated with PRF with conventional open-flap debridement compared to conventional open-flap debridement alone. However, a long-term, multicentered randomized controlled clinical trial is required to know the clinical and radiographic effects of PRF on bone regeneration.

Platelet concentrates: past, present and future

Platelets play a crucial role in hemostasis and wound healing, platelet growth factors are well known source of healing cytokines. Numerous techniques of autologous platelet concentrates have been developed and applied in oral and maxillofacial surgery. This review describes the evolution of the first and second generation of platelet concentrates (platelet rich plasma and platelet rich fibrin respectively) from their fore runner-fibrin sealants.

Autologous platelet-rich fibrin in the treatment of mandibular degree II furcation defects: a randomized clinical trial

BACKGROUND

Platelet-rich fibrin (PRF), an intimate assembly of cytokines, glycan chains, and structural glycoproteins enmeshed within a slowly polymerized fibrin network, has the potential to accelerate soft and hard tissue healing. This double-masked randomized study is designed to evaluate the effectiveness of autologous PRF in the treatment of mandibular degree II furcation defects compared with open flap debridement (OFD).

METHODS

Using a split-mouth design, 18 patients with 36 mandibular degree II furcation defects were randomly allotted and treated either with autologous PRF and OFD or OFD. Plaque index, sulcus bleeding index, probing depth, relative vertical and horizontal clinical attachment level, gingival marginal level, and radiographic bone defect were recorded at baseline and 9 months postoperatively. Comparison between indices between the test and control groups was performed using the paired t test except for plaque index and sulcus bleeding index data, which used the χ(2) test.

RESULTS

All clinical and radiographic parameters showed statistically significant improvement at the sites treated with PRF and OFD compared to those with OFD alone.

CONCLUSION

Within the limitation of this study, significant improvement with autologous PRF implies its role as a regenerative material in the treatment of furcation defects.

Platelet-rich fibrin is a Bioscaffold and reservoir of growth factors for tissue regeneration

The platelet-rich fibrin (PRF) is known as a rich source of autologous cytokines and growth factors and universally used for tissue regeneration in current clinical medicine. However, the microstructure of PRF has not been fully investigated nor have been studied the key molecules that differ PRF from platelet-rich plasma. We fabricated PRF under Choukroun's protocol and produced its extract (PRFe) by freezing at -80°C. The conventional histological, immunohistological staining, and scanning electron microscopy images showed the microstructure of PRF, appearing as two zones, the zone of platelets and the zone of fibrin, which resembled a mesh containing blood cells. The PRFe increased proliferation, migration, and promoted differentiation of the human alveolar bone marrow stem cells (hABMSCs) at 0.5% concentration in vitro. From the results of proteome array, matrix metalloproteinase 9 (MMP9) and Serpin E1 were detected especially in PRFe but not in concentrated platelet-rich plasma. Simultaneous elevation of MMP9, CD44, and transforming growth factor β-1 receptor was shown at 0.5% PRFe treatment to the hABMSC in immunoblot. Mineralization assay showed that MMP9 directly regulated mineralization differentiation of hABMSC. Transplantation of the fresh PRF into the mouse calvarias enhanced regeneration of the critical-sized defect. Our results strongly support the new characteristics of PRF as a bioscaffold and reservoir of growth factors for tissue regeneration.

Fixed rehabilitation of severely atrophic jaws using immediately loaded basal disk implants after in situ bone activation

Rehabilitation of severely atrophic jaws is facilitated when basal disk implants are used after activation of the future bony implant bed with a purpose-designed instrument (Osteotensor) 45 to 90 days before implant surgery. Fabrication of a highly rigid, screw-secured fixed prosthesis that acts as an external orthopedic fixator permits immediate functional loading. This protocol also represents a second chance for patients who have experienced complete implant loss and/or bone graft failure.

Platelet-rich fibrin increases proliferation and differentiation of human dental pulp cells

INTRODUCTION

Platelet-rich fibrin (PRF) by Choukroun's technique is derived from an autogenous preparation of concentrated platelets without any manipulation. When delicately pressed between 2 gauzes, the PRF clot becomes a strong membrane with high potential in clinical application. However, the effect of PRF on dental pulp cells (DPCs) remains to be elucidated. This study was to determine the biological effects of PRF on DPCs.

METHODS

PRF samples were obtained from 6 healthy volunteers. Human DPCs were derived from healthy individuals undergoing extraction for third molars. Cell proliferation resulting from PRF was evaluated by colorimetric assay. Western blot was used to evaluate the expression of osteoprotegerin (OPG). Alkaline phosphatase (ALP) activity was examined by substrate assay.

RESULTS

PRF did not interfere with cell viability of DPCs (P > .05). DPCs were observed to attach at the edges of PRF by phase-contrast microscopy. PRF was found to increase DPC proliferation during 5-day incubation period (P < .05). PRF was found to increase OPG expression in a time-dependent manner (P < .05). ALP activity was also significantly up-regulated by PRF (P < .05).

CONCLUSIONS

PRF was demonstrated to stimulate cell proliferation and differentiation of DPCs by up-regulating OPG and ALP expression. These findings might serve as a basis for preclinical studies that address the role of PRF in reparative dentin formation.

Platelet-rich fibrin membranes as scaffolds for periosteal tissue engineering

OBJECTIVES

Platelet-rich fibrin (PRF)-based membranes have been used for covering alveolar ridge augmentation side in several in vivo studies. Few in vitro studies on PRF and no studies using human periosteal cells for tissue engineering have been published. The aim is a comparison of PRF with the commonly used collagen membrane Bio-Gide as scaffolds for periosteal tissue engineering.

MATERIAL AND METHODS

Human periosteal cells were seeded on membrane pieces (collagen [Bio-Gide] and PRF) at a density of 10(4) cells/well. Cell vitality was assessed by fluorescein diacetate (FDA) and propidium iodide (PI) staining, biocompatibility with the lactate dehydrogenase (LDH) test and proliferation level with the MTT, WST and BrdU tests and scanning electron microscopy (SEM).

RESULTS

PRF membranes showed slightly inferior biocompatibility, as shown by the LDH test. The metabolic activity measured by the MTT and WST tests was higher for PRF than for collagen (BioGide). The proliferation level as measured by the BrdU test (quantitative) and SEM examinations (qualitative) revealed higher values for PRF.

CONCLUSION

PRF appears to be superior to collagen (Bio-Gide) as a scaffold for human periosteal cell proliferation. PRF membranes are suitable for in vitro cultivation of periosteal cells for bone tissue engineering.

[The use of platelet-rich fibrin membrane in gingival recession treatment]

INTRODUCTION

Fibrin, fibronectin, platelet derived growth factor, and transforming growth factors from platelet concetrate are crucial for tissue reparation and regeneration.

OBJECTIVE

This study was designed to evaluate clinical effectiveness of activated platelet-rich fibrin (PRF) membrane in treatment of gingival recession.

METHODS

19 gingival recessions Miller class I or II were treated with a coronally advanced flap and the PRF membrane (PRF group). Following the elevation of the flap, bone and root surfaces were covered with the PRF membrane. After suturing, the PRF membrane was covered with a coronally advanced flap. In the same patients, 19 other gingival recessions were treated with CTG in combination with the coronally advanced flap (the CTG group). Clinical recordings were made of vertical recession depth (VRD), probing depth (PD), clinical attachment level (CAL) and keratinized tissue width (KTW) before and 12 months after mucogingival surgical treatment. Clinical evaluation of healing events was estimated with recordings of the healing index (HI). Recordings of HI were performed in the 1st, 2nd and 3rd week post-surgically.

RESULTS

Mean root coverage was significant in both groups (the PRF group 79.94% and the CTG group 88.56% %; p < 0.01). The difference between the two tested groups was not statistically significant. Results of the keratinized tissue width showed significant increase (p < 0.05) 12 months after the surgery in both, the PRF and CTG groups. Results of KTW showed statistical significance of recorded differences obtained in the two evaluated groups (p < 0.05). There was no statistical significance in reduction of PD and CAL recorded in the PRF and CTG groups. The values of HI recorded in the 1st and 2nd week postoperatively were significantly enhanced in the PRF group (p < 0.05).

CONCLUSION

Results of this study confirm both procedures as effective with equivalence of clinical results in solving gingival recession problems. The utilization of the PRF resulted in a decreased postoperative discomfort and advanced tissue healing.