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

Clinical and radiographic evaluation of nanocrystalline hydroxyapatite with or without platelet-rich fibrin membrane in the treatment of periodontal intrabony defects

Background:

Nano-sized ceramics may represent a promising class of bone graft substitutes due to their improved osseointegrative properties. Nanocrystalline hydroxyapatite (NcHA) binds to bone and stimulate bone healing by stimulation of osteoblast activity. 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. The present study aims to explore the clinical and radiographical outcome of NcHA bone graft with or without PRF, in the treatment of intrabony periodontal defects.

Materials and Methods:

In a split-mouth study design, 20 patients having two almost identical intrabony defects with clinical probing depth of at least 6 mm were selected for the study. Selected sites were randomly divided into two groups. In Group I, mucoperiosteal flap elevation followed by the placement of NcHA was done. In Group II, mucoperiosteal flap elevation, followed by the placement of NcHA with PRF was done. Clinical and radiographic parameters were recorded at baseline and at 6-month postoperatively.

Results:

Both treatment groups showed a significant probing pocket depth (PPD) reduction, clinical attachment gain, increase bone density 6-month after surgery compared with baseline. However, there was a significantly greater PPD reduction and clinical attachment gain when PRF was added to NcHA.

Conclusion:

The NcHA bone graft in combination with PRF demonstrated clinical advantages beyond that achieved by the NcHA alone.

Treatment of Oral Mucosal Lesions by Scalpel Excision and Platelet-Rich Fibrin Membrane Grafting: A Review of 26 Sites

PURPOSE

One of the preferred treatment options for oral mucosal lesions (eg, leukoplakia and lichen planus) is excision, with or without the use of a coverage agent. Platelet-rich fibrin (PRF) membranes are popular fibrin scaffolds with entrapped platelets that release various growth factors and cytokines to support and enhance wound healing. The aim of the present report was to describe the technique, postoperative wound care, and clinical results of PRF membrane grafting after excision of superficial potentially malignant oral lesions.

MATERIALS AND METHODS

Autologous PRF membrane was fabricated and grafted over 26 wounds created by excision of small, superficial, potentially malignant lesions of oral mucosa (or fiberotomy in cases of oral submucous fibrosis) and assessed clinically at 7, 15, 30, and 60 days.

RESULTS

Healing was satisfactory in all cases, with minimal and manageable complication at 1 site.

CONCLUSION

The results of the present study suggest that PRF membrane is a successful coverage agent that aids in the healing of superficial oral mucosal wounds. Additional comparative studies are required to establish its efficacy compared with that of other agents.

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

Choukroun's platelet-rich fibrin (PRF) is obtained from blood without adding anticoagulants. In this study, protocols for standard platelet-rich fibrin (S-PRF) (2700 rpm, 12 minutes) and advanced platelet-rich fibrin (A-PRF) (1500 rpm, 14 minutes) were compared to establish by histological cell detection and histomorphometrical measurement of cell distribution the effects of the centrifugal force (speed and time) on the distribution of cells relevant for wound healing and tissue regeneration. Immunohistochemistry for monocytes, T and B -lymphocytes, neutrophilic granulocytes, CD34-positive stem cells, and platelets was performed on clots produced from four different human donors. Platelets were detected throughout the clot in both groups, although in the A-PRF group, more platelets were found in the distal part, away from the buffy coat (BC). T- and B-lymphocytes, stem cells, and monocytes were detected in the surroundings of the BC in both groups. Decreasing the rpm while increasing the centrifugation time in the A-PRF group gave an enhanced presence of neutrophilic granulocytes in the distal part of the clot. In the S-PRF group, neutrophils were found mostly at the red blood cell (RBC)-BC interface. Neutrophilic granulocytes contribute to monocyte differentiation into macrophages. Accordingly, a higher presence of these cells might be able to influence the differentiation of host macrophages and macrophages within the clot after implantation. Thus, A-PRF might influence bone and soft tissue regeneration, especially through the presence of monocytes/macrophages and their growth factors. The relevance and feasibility of this tissue-engineering concept have to be proven through in vivo studies.

Management of a pathologically migrated upper anterior tooth using platelet-rich fibrin and a modified crown preparation technique

In adult periodontal patients, pathologic tooth migration can create serious functional and aesthetic problems. In such situations, a combined orthodontic and periodontal treatment is often indicated. However, the lengthy treatment time and the demanding nature of orthodontic therapy for such periodontally compromised teeth is often a challenge. In this case report, an approach combining platelet-rich fibrin for the treatment of osseous defect and a modified crown preparation technique to reposition the crown was done on a pathologically migrated right lateral incisor.

Effectiveness of autologous platelet-rich fibrin in the treatment of intra-bony defects: A systematic review and meta-analysis

The aim of the present meta-analysis is to determine the clinical and radiographic outcomes of using platelet-rich fibrin (PRF) for the treatment of periodontal intra-bony defect (IBD) compared with open flap debridement (OFD). MEDLINE/PubMed, EBSCO and Cochrane database were used to identify studies in English language published from January 1, 2005 to January 31, 2013. An additional hand search of the relevant journals and of the bibliographies of the paper identified was also performed. Articles retrieved were screened using specific inclusion criteria by five independent reviewers: Studies investigating the effect of platelet concentrate in surgical procedure for the treatment of periodontal intra osseous defects compared with the control group in which platelet concentrate was not used were included. Five relevant articles were selected for the meta-analysis of which 3 articles were retrieved after electronic search and two articles were included after hand search. The number of patients in studies ranged from 15 to 62 (32-90 sites) with mean age ranging from 29.47 to 39.7. A total of 298 sites were treated using PRF either in combination with graft or as a monotherapy in comparison to traditional OFD procedure. The meta-analysis showed a standard mean difference of 0.95 mm; 95% confidence interval (CI): 0.20-1.71 in clinical attachment level (CAL) and 2.33 mm; 95% CI: 1.43-3.23 in IBD after treatment of IBD with PRF compared with OFD. The meta-analysis showed clinically significant improvements in periodontal parameters such as CAL, IBD, and reduction in probing depth when IBDs were treated with PRF alone when compared to OFD.

Platelet derivatives in regenerative medicine: an update

Prior preclinical and clinical studies support the use of platelet-derived products for the treatment of soft and hard tissue lesions. These regenerative effects are controlled by autocrine and paracrine biomolecules including growth factors and cytokines contained in platelet alpha granules. Each growth factor is involved in a phase of the healing process, such as inflammation, collagen synthesis, tissue granulation, and angiogenesis collectively promoting tissue restitution. Platelet derivatives have been prepared as platelet-rich plasma, platelet gel, platelet-rich fibrin, and platelet eye drops. These products vary in their structure, growth factors, composition, and cytokine concentrations. Here, we review the current use of platelet-derived biological products focusing on the rationale for their use and the main requirements for their preparation. Variation in the apparent therapeutic efficacy may have resulted from a lack of reproducible, standardized protocols for preparation. Despite several individual studies showing favorable treatment effects, some randomized controlled trials as well as meta-analyses have found no constant clinical benefit from the application of platelet-derived products for prevention of tissue lesions. Recently, 3 published studies in dentistry showed an improvement in bone density. Seven published studies showed positive results in joint regeneration. Five published studies demonstrated an improvement in the wound healing, and an improvement of eye epithelial healing was observed in 2 reports. Currently, at least 14 ongoing clinical trials in phase 3 or 4 have been designed with large groups of treated patients (n > 100). Because the rationale of the therapy with platelet-derived compounds is still debated, a definitive insight can be acquired only when these large randomized trials will be completed.

Evaluation of intrabony defects treated with platelet-rich fibrin or autogenous bone graft: A comparative analysis

OBJECTIVE

The primary objective of this study was to compare clinically and radiographically the efficacy of autologous platelet rich fibrin (PRF) and autogenous bone graft (ABG) obtained using bone scrapper in the treatment of intrabony periodontal defects.

MATERIALS AND METHODS

Thirty-eight intrabony defects (IBDs) were treated with either open flap debridement (OFD) with PRF or OFD with ABG. Clinical parameters were recorded at baseline and 6 months postoperatively. The defect-fill and defect resolution at baseline and 6 months were calculated radiographically (intraoral periapical radiographs [IOPA] and orthopantomogram [OPG]).

RESULTS

Significant probing pocket depth (PPD) reduction, clinical attachment level (CAL) gain, defect fill and defect resolution at both PRF and ABG treated sites with OFD was observed. However, inter-group comparison was non-significant (P > 0.05). The bivariate correlation results revealed that any of the two radiographic techniques (IOPA and OPG) can be used for analysis of the regenerative therapy in IBDs.

CONCLUSION

The use of either PRF or ABG were effective in the treatment of three wall IBDs with an uneventful healing of the sites.

Evaluation of osteoblastic activity in extraction sockets treated with platelet-rich fibrin

OBJECTIVE

The aim of this study was to determine whether the use of platelet rich fibrin (PRF) improved the healing of extraction sockets.

STUDY DESIGN

A total of 20 patients with bilateral soft tissue impacted mandibular third molars were included in this study. The left and right third molars were extracted during the same session. Subsequently, the PRF membrane was randomly administered to one of the extraction sockets, whereas the contralateral sockets were left without treatment. On postoperative 30. and 90. days, panoramic images and bone scintigrams were taken to evaluate the bone healing between PRF-treated and non-PRF-treated sockets. Also, periodontal evaluation was performed in the same control sessions. Dependent group t test for paired samples was used for statistical analysis.

RESULTS

The average increase in technetium-99m methylene diphosphonate uptake as an indication of enhanced bone healing did not differ significantly between PRF-treated and non-PRF-treated sockets 30 and 90 days postoperatively. Radio-opacity that can show the bone healing on panoramic images were measured by Image J programme and they did not differ significantly. Also periodontal values did not differ significantly.

CONCLUSIONS

PRF might not lead to enhanced bone healing in impacted mandibular third molar extraction sockets 30 and 90 days after surgery. It is thought that PRF has the potential characteristics of an autologous fibrin matrix and can accelerate the healing. To better understand the effects of PRF on healing, further research is warranted with larger sample sizes.

Influence of the association between platelet-rich fibrin and bovine bone on bone regeneration. A histomorphometric study in the calvaria of rats

This study aimed to investigate the effects of platelet-rich fibrin (PRF) associated or not with Bio-Oss on bone defects in the calvaria of rats. A critical-size defect of 5-mm diameter was performed in the calvaria of 48 rats. These animals were divided into six groups of eight animals each, according to the treatment received: homogeneous clot, autogenous clot, autogenous PRF, homogeneous PRF, Bio-Oss, or Bio-Oss associated with PRF. The animals were euthanized after 30 or 60 days. Bone regeneration was evaluated by histomorphometric analysis. The highest mean percentages of new bone formation at 30 days (54.05% ± 5.78) and 60 days (63.58% ± 5.78) were observed in the Bio-Oss associated with PRF group; in particular, the percentage of new bone at 30 days was significantly higher than that of all of the other groups (P<0.01). At 60 days, the Bio-Oss associated with PRF (63.58% ± 5.78) and Bio-Oss (57.34% ± 5.78) groups had similar results, and both showed a statistical difference compared to the other groups. PRF had a positive effect on bone regeneration only when associated with Bio-Oss.

Evolution of Barrier Membranes in Periodontal Regeneration-"Are the third Generation Membranes really here?"

In the last decades, Guide Tissue Regeneration (GTR) technique has been applied for the treatment of various periodontal defects such as intrabony defects, furcation involvements and localized gingival recession defects. From early days of using membranes with the simple aim of minimizing toxic response in the host, membranes have come a long way. Third generation membranes not only act as barriers but also as delivery devices to release specific agents. Many clinical trials have focused on using membranes as delivery devices for antibiotics and growth factors. In this article we take a brief look at the evolution of barrier membranes and future avenues with regard to third generation membranes.

Clinical evaluation of autologous platelet rich fibrin in horizontal alveolar bony defects

BACKGROUND

Horizontal bone loss is the most common periodontal problem confronting the clinician but has received little attention. Platelet rich fibrin (PRF) is a second generation platelet concentrate. The platelets, leucocytes, growth factors and cytokines contained within PRF make it a healing biomaterial with tremendous potential for bone and soft tissue regeneration.

AIM

This interventional clinical trial evaluates the clinical effectiveness of Autologous Platelet Rich Fibrin (PRF) in the management of horizontal bony defects.

SETTINGS AND DESIGN

Department of Periodontics. Design was Non Randomized Clinical Trial with split mouth design.

MATERIALS AND METHODS

A total of 45 sites with horizontal bone loss in 15 patients were studied, 15 sites were treated with PRF gel (experimental group I) and 15 sites were treated with PRF gel and PRF membrane (experimental group II). Control group (15 sites) were treated with open flap debridement.

STATISTICAL ANALYSIS

All the parameters were assessed at baseline and after nine months which included Pocket Depth (PD), Clinical Attachment level (CAL), Gingival Recession (REC) and Relative Crest Height (RCH). The mean changes at baseline and after 9 months within each group were compared using Wilcoxon Signed Ranks Test. The mean changes for each parameter between groups were compared using Kruskal Wallis Test.

RESULTS

Re-evaluation at nine months revealed that all groups showed a significant reduction in probing depth (1.1±0.38 mm in control, 1.73±0.53 mm in group I, 1.7±0.45 mm in group II)(p<0.05) and clinical attachment gain (0.86±0.58 mm in control, 1.56±0.62 mm in group I, 1.7±0.52 in group II)(p<0.05) as compared to baseline. Intergroup comparisons of reduction in probing depth and clinical attachment gain showed significant differences in the experimental groups as compared to control (p<0.05), but there was no significant difference between the experimental groups (p>0.05). There was no significant difference in gingival recession and radiographic bone levels at 9 months post surgery (p>0.05) in all the three groups.

CONCLUSION

Within the limitations of this study, it can be concluded that, clinically the use of PRF in both gel and membrane form is more effective than open flap debridement alone in the management of horizontal periodontal defects at nine months post surgery.

Leucocyte-rich and platelet-rich fibrin for the treatment of bisphosphonate-related osteonecrosis of the jaw: a prospective feasibility study

Our aim was to assess the feasibility of using leucocyte-rich and platelet-rich fibrin (L-PRF) for the treatment of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in a single group study. After treatment with L-PRF, the response of each patient was recorded 1 month and 4 months postoperatively. Further assessments were made of the site, stage, concentration of c-terminal crosslinked telopepide of type 1 collagen, and actinomycosis. Among the total of 34 patients, 26 (77%) showed complete resolution, 6 (18%) had delayed resolution, and 2 (6%) showed no resolution. There was a significant association between the response to treatment and the stage of BRONJ (p=0.002) but no other significant associations were detected. This study has shown that it is feasible to use L-PRF for the treatment of BRONJ, but the effectiveness cannot be judged with this study design. Randomised prospective trials are needed to confirm this.

Fibrin, a scaffold material for islet transplantation and pancreatic endocrine tissue engineering

Fibrin is derived from fibrinogen during injury to produce a blood clot and thus promote wound repair. Composed of different domains, including Arg-Gly-Asp amino acid motifs, fibrin is used extensively as a hydrogel and sealant in the clinic. By binding to cell surface receptors like integrins and acting as a supportive 3D scaffold, fibrin has been useful in promoting cell differentiation, proliferation, function, and survival. In particular, fibrin has been able to maintain islet cell architecture, promote beta cell insulin secretion, and islet angiogenesis, as well as inducing a protective effect against cell death. During islet transplantation, fibrin improved neovascularization and islet function. These improvements resulted in reduced number of transplanted islets necessary to reverse diabetes. Therefore, fibrin, as a biocompatible and biodegradable scaffold, should be considered during subcutaneous islet transplantation and beta cell expansion in vitro to ensure maintenance of islet cell function, proliferation, and survival to develop effective cell-based therapies for the treatment of diabetes.

Formation of blood clot on biomaterial implants influences bone healing

The first step in bone healing is forming a blood clot at injured bones. During bone implantation, biomaterials unavoidably come into direct contact with blood, leading to a blood clot formation on its surface prior to bone regeneration. Despite both situations being similar in forming a blood clot at the defect site, most research in bone tissue engineering virtually ignores the important role of a blood clot in supporting healing. Dental implantology has long demonstrated that the fibrin structure and cellular content of a peri-implant clot can greatly affect osteoconduction and de novo bone formation on implant surfaces. This article reviews the formation of a blood clot during bone healing in relation to the use of platelet-rich plasma (PRP) gels. It is implicated that PRP gels are dramatically altered from a normal clot in healing, resulting in conflicting effect on bone regeneration. These results indicate that the effect of clots on bone regeneration depends on how the clots are formed. Factors that influence blood clot structure and properties in relation to bone healing are also highlighted. Such knowledge is essential for developing strategies to optimally control blood clot formation, which ultimately alter the healing microenvironment of bone. Of particular interest are modification of surface chemistry of biomaterials, which displays functional groups at varied composition for the purpose of tailoring blood coagulation activation, resultant clot fibrin architecture, rigidity, susceptibility to lysis, and growth factor release. This opens new scope of in situ blood clot modification as a promising approach in accelerating and controlling bone regeneration.

Platelet-rich fibrin as an adjunct to palatal wound healing after harvesting a free gingival graft: A case series

Background:

Owing to its stimulatory effect on angiogenesis and epithelialization, platelet-rich fibrin (PRF) is an excellent material for enhancing wound healing. The use of PRF dressings may be a simple and effective method of reducing the morbidity associated with donor sites of autogenous free gingival grafts (FGGs). The purpose of this case series is to document the beneficial role of PRF in the healing of FGG donor sites.

Materials and Methods:

A total of 18 patients treated with FGGs could be classified into two groups. PRF was prepared, compressed and used to dress the palatal wound followed by a periodontal pack in one group (10 patients) and only a periodontal pack was used in the other group (8 patients). Post-operative healing was assessed clinically at 7, 14 and 21 days and the morbidity was assessed qualitatively by an interview.

Results:

Sites where PRF was used showed complete wound closure by 14 days and these patients reported lesser post-operative morbidity than patients in whom PRF was not used.

Conclusions:

PRF as a dressing is an effective method of enhancing the healing of the palatal donor site and consequently reducing the post-operative morbidity.

Role of platelet rich fibrin and platelet rich plasma in wound healing of extracted third molar sockets: a comparative study

AIMS AND OBJECTIVES

This prospective study was done to evaluate and compare the utility and effectiveness of platelet rich fibrin (PRF) with that of platelet rich plasma (PRP) on soft tissue healing and bone tissue healing of extracted third molar sockets.

MATERIALS AND METHODS

This study included split mouths of 20 patients who underwent bilateral extraction of impacted third molars. During the same appointment, following which PRF and PRP were prepared from patients' autologous blood and placed in right and left extracted sockets, respectively. The data for soft tissue healing were recorded at end of 1 week, using healing index of Landry et al. and the data for bone tissue healing were recorded at the end of 4 months using digitalized orthopantomogram images on Adobe Photoshop CS; which was then compared between the two sites of the same patient.

RESULTS

The mean values of soft tissue healing collected at 1 week post-operative, for PRF group were significantly higher as compared to PRP group. And the mean values of bone density collected at the end of fourth month post-operative, for PRF group were also significantly higher as compared to PRP group. Both tests showed p value of 0.00.

CONCLUSION

PRF is significantly better in promoting soft tissue healing and also faster regeneration of bone after third molar extraction, in comparison with PRP. This could be attributed to simpler preparation protocols of PRF over PRP and the ability of PRF to release growth factors in a controlled way.

Effect of autologous platelet rich fibrin on the healing of experimental articular cartilage defects of the knee in an animal model

The effect of autologous platelet rich fibrin (PRF), a second generation platelet product, on the healing of experimental articular cartilage lesions was evaluated in an animal model. Full thickness cartilage lesions with a diameter of 6 mm and depth of 5 mm were created in the weight bearing area of femoral condyles of both hind limbs in 12 adult mixed breed dogs. Defects in the left hind limb of each dog were repaired by PRF implantation whereas those in the right hind limb were left empty. The animals were euthanized at 4, 16, and 24 weeks following surgery and the resultant repair tissue was investigated macroscopically and microscopically. The results of macroscopic and histological evaluations indicated that there were significant differences between the PRF treated and untreated defects. In conclusion, the present study indicated that the use of platelet rich fibrin as a source of autologous growth factors leads to improvement in articular cartilage repair.

Lyophilized platelet-rich fibrin (PRF) promotes craniofacial bone regeneration through Runx2

Freeze-drying is an effective means to control scaffold pore size and preserve its composition. The purpose of the present study was to determine the applicability of lyophilized Platelet-rich fibrin (LPRF) as a scaffold for craniofacial tissue regeneration and to compare its biological effects with commonly used fresh Platelet-rich fibrin (PRF). LPRF caused a 4.8-fold±0.4-fold elevation in Runt-related transcription factor 2 (Runx2) expression in alveolar bone cells, compared to a 3.6-fold±0.2-fold increase when using fresh PRF, and a more than 10-fold rise of alkaline phosphatase levels and mineralization markers. LPRF-induced Runx2 expression only occurred in alveolar bone and not in periodontal or dental follicle cells. LPRF also caused a 1.6-fold increase in osteoblast proliferation (p<0.001) when compared to fresh PRF. When applied in a rat craniofacial defect model for six weeks, LPRF resulted in 97% bony coverage of the defect, compared to 84% for fresh PRF, 64% for fibrin, and 16% without scaffold. Moreover, LPRF thickened the trabecular diameter by 25% when compared to fresh PRF and fibrin, and only LPRF and fresh PRF resulted in the formation of interconnected trabeculae across the defect. Together, these studies support the application of lyophilized PRF as a biomimetic scaffold for craniofacial bone regeneration and mineralized tissue engineering.

Clinical and histological evaluation of postextraction platelet-rich fibrin socket filling: a prospective randomized controlled study

OBJECTIVES

The aims were to investigate whether the use of platelet-rich fibrin membranes (PRF) for socket filling could improve microarchitecture and intrinsic bone tissue quality of the alveolar bone after premolar extraction and to assess the influence of the surgical procedure before implant placement.

MATERIAL AND METHODS

Twenty-three patients requiring premolar extraction followed by implant placement were randomized to three groups: (1) simple extraction and socket filling with PRF, (2) extraction with mucosal flap and socket filling with PRF, and (3) controls with simple extraction without socket filling. Implant placement was performed at week 8, and a bone biopsy was obtained for histomorphometric analysis.

RESULTS

Analysis by microcomputed tomography showed better bone healing with improvement of the microarchitecture (P < 0.05) in group 1. This treatment had also a significant effect (P < 0.05) on intrinsic bone tissue quality and preservation of the alveolar width. An invasive surgical procedure with a mucosal flap appeared to completely neutralize the advantages of the PRF.

CONCLUSIONS

These results support the use of a minimally traumatic procedure for tooth extraction and socket filling with PRF to achieve preservation of hard tissue.

Clinical application of platelet-rich fibrin by the application of the Double J technique during implant placement in alveolar bone defect areas: case reports

Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates, with simplified processing and without biochemical blood handling. PRF releases growth factors and matrix glycoproteins. In this study, the Double J technique was used. The Double J technique, which uses centrifuged venous blood that is sampled using 2 different types of DB vacutainers, is a procedure that covers the PRF matrix obtained from 1 of the DB vacutainers on transplanted osseous coagulum, which is obtained using the plasma layer and buffering layer from the second DB vacutainer. Two cases were reported because clinically valid results were obtained. Additional studies are definitely warranted.

Platelet-rich fibrin in the treatment of periodontal bone defects

BACKGROUND

Periodontitis is characterized by the formation of true pockets, bone loss and attachment loss. Various techniques have been attempted in the past to truly regenerate the lost periodontal structures, albeit with variable outcome. In this evolution, the technique being tried out widely is the use of platelet rich concentrates, namely platelet-rich fibrin (PRF).

CASE DESCRIPTION

In this report, we present a case of surgical treatment of osseous bone defects namely two walled crater and dehiscence treated in posterior teeth with autologously prepared platelet rich fibrin mixed with hydroxy apatite bone graft and PRF in the form of a membrane.

CONCLUSION

Our results showed clinical improvements in all the clinical parameters postoperatively namely the pocket depth reduction and gain in attachment level and hence, PRF can be used alone or in combination with the bone graft to yield successful clinical results in treating periodontal osseous defects.

CLINICAL SIGNIFICANCE

Platelet-rich fibrin is an effective alternative to platelet-rich plasma (PRP) in reconstructing bone defects.

Preliminary experience with the use of an autologous platelet-rich fibrin membrane for urethroplasty coverage in distal hypospadias surgery

OBJECTIVE

Platelet-rich fibrin (PRF) has been shown to have structural and biological properties that promote tissue healing. This prospective study evaluated the feasibility, safety, and efficiency of using autologous PRF membrane for urethroplasty coverage in distal hypospadias.

MATERIALS AND METHODS

We prospectively included 33 patients with distal hypospadias operated on between June 2010 and September 2011. Urethroplasties were performed using the Duplay technique. During surgery, 5-10 ml of patient's blood was collected and immediately centrifuged. A PRF clot was transformed into a dense fibrin membrane with a particular cell content and architecture. This membrane was applied and sutured over the urethroplasty. The perioperative course and complications were recorded. Outcomes were compared with those in a control group of children undergoing the same procedure, but with another mean of coverage.

RESULTS

With a median follow-up of 8 months (range, 6-18 months), urethral fistula occurred in 2/33 patients. No other complication was noted. No complication related to the blood sampling was reported. There was no statistically significant difference with the control group (p = 0.65).

CONCLUSION

The PRF patch seems to be a safe and efficient covering technique. Thus, procedure is an additional approach to coverage for hypospadias surgery, and may help to reduce the incidence of postoperative complications when coverage healthy tissue is not available.

Buccal bone deficiency in fresh extraction sockets: a prospective single cohort study

OBJECTIVE

The purpose of this prospective single cohort study was to evaluate the use of xenograft and collagen membranes in treating full or partial buccal bone defects of fresh extraction sockets in the esthetic zone.

MATERIALS AND METHODS

Thirty-three patients requiring tooth extraction in the anterior maxillary area and showing a complete or partial buccal bone plate deficiency (more than 2 mm) were consecutively enrolled and treated. Corticocancellous porcine bone and platelet-rich fibrin (PRF) with a collagen membrane were used to graft the extraction sockets, and the membranes were left exposed to the oral cavity with a secondary soft tissue healing. The outcome variables were as follows: width of keratinized mucosa, facial soft tissue levels, clinical bone changes (measured with a clinical splint), implant and prosthesis failures, and peri-implant marginal bone changes.

RESULTS

All treated sites allowed the placement of implants; the width of keratinized mucosa at the mid-facial aspect showed an increase of 2.3 mm 5 months after the grafting procedure, and its value was 3.2 ± 0.6 mm at 1-year follow-up. The mean values of the facial soft tissue level indicated an increase over time. The bone level showed an improvement of 0.8 ± 0.1 mm and 0.7 ± 0.1 mm at mesial and distal sites, respectively, when compared to the baseline measurements. Finally, in the palatal area, no bone changes were observed. No implant failed during the entire observation period.

CONCLUSIONS

Findings from this study showed that xenograft and PRF, used for ridge preservation of the extraction sockets with buccal bone plate dehiscence in the esthetic zone, can be considered effective in repairing bone defects before implant placement. The secondary soft tissue healing over the grafted sockets did not compromise bone formation; moreover, the soft tissue level and the width of keratinized gingiva showed a significant improvement over time.

Comparison of platelet-rich plasma (PRP), platelet-rich fibrin (PRF), and concentrated growth factor (CGF) in rabbit-skull defect healing

OBJECTIVES

The objective of this study was to evaluate the effect of platelet-rich plasma (PRP), platelet-rich fibrin (PRF), and concentrated growth factor (CGF) on bone healing.

STUDY DESIGN

Twelve rabbits were included in this randomized, blinded, prospective study. 15-mm×10-mm-sized defects were created in the parietal bone, filled with PRP, PRF, CGF, and void. The bone mineral density and bone volume were analyzed with microscopic computed tomography (micro-CT) and histomorphometrics at the 6th and 12th week.

RESULTS

In micro-CT analysis, bone mineral density and bone volume were greater in the experimental group than in controls at both 6th and 12th week, but not among the experimental groups. Similarly, histomorphometric examination revealed that more bone formation was seen in the experimental group.

CONCLUSION

The addition of PRP, PRF, and CGF had significantly increased bone formation at the 6th week. The effect of PRP, PRF, and CGF was similar and may be useful in the future to increase the success rate of bone grafting.

A novel platelet concentrate: titanium-prepared platelet-rich fibrin

We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF). The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun's leukocyte- and platelet-rich fibrin (L-PRF) method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn using a syringe. Nine milliliters was transferred to a dry glass tube, and 9 mL was transferred to a titanium tube. Half of each clot (i.e., the blood that was clotted using T-PRF or L-PRF) was processed with a scanning electron microscope (SEM). The other half of each clot was processed for fluorescence microscopy analysis and light microscopy analysis. The T-PRF samples seemed to have a highly organized network with continuous integrity compared to the other L-PRF samples. Histomorphometric analysis showed that T-PRF fibrin network covers larger area than L-PRF fibrin network; also fibrin seemed thicker in the T-PRF samples. This is the first human study to define T-PRF as an autogenous leukocyte- and platelet-rich fibrin product. The platelet activation by titanium seems to offer some high characteristics to T-PRF.

Platelet rich fibrin - a novel acumen into regenerative endodontic therapy

Research into regenerative dentistry has added impetus onto the field of molecular biology. It can be documented as a prototype shift in the therapeutic armamentarium for dental disease. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. A new family of platelet concentrates called the platelet rich fibrin (PRF) has been recently used by several investigators and has shown application in diverse disciplines of dentistry. This paper is intended to add light on the various prospects of PRF and clinical insights to regenerative endodontic therapy.

The bone integration effects of platelet-rich fibrin by removal torque of titanium screw in rabbit tibia

Platelet-rich fibrin (PRF) is nowadays often used in various fields, but no removal torque studies have yet been done to evaluate the effects of the platelet-rich fibrin on the bone integration at the initial healing period. An experimental study have been performed in rabbits to evaluate whether the complete PRF clots can accelerate the bone integration of implants at the initial healing period after creating bone defects in tibias. The effect of the complete PRF clots on bone integration was studied in two rabbit groups, 4-week group (group A) and 6-week group (group B) after preparing bony defects. Artificial bony defects were prepared in the tibias of rabbits. The complete PRF clots was applied to the defects in the experimental group, whereas the defects were unfilled in the control group. Four weeks later, machined implants were installed into the rabbit tibias (group A). Six weeks after installation, the removal torque from nine rabbits was measured to examine the bone healing effect of PRF. In another rabbits (group B), 6 weeks after preparing bony defects, installation was performed, and another 6 weeks after installation, the removal torque from nine rabbits was measured. The authors found a positive significant effect of the complete PRF clots on bone integration (higher bone density) in group A installed at 4 weeks after preparing bony defects (p = 0.008; t-test), but not in group B installed at 6 weeks after preparing bony defects (p = 0.677).

The influence of platelet-rich fibrin on angiogenesis in guided bone regeneration using xenogenic bone substitutes: a study of rabbit cranial defects

PURPOSE

The purpose of this study was to investigate the influence of platelet-rich fibrin (PRF) on angiogenesis and osteogenesis in guided bone regeneration (GBR) using xenogenic bone in rabbit cranial defects.

MATERIALS AND METHODS

In each rabbit, 2 circular bone defects, one on either side of the midline, were prepared using a reamer drill. Each of the experimental sites received bovine bone with PRF, and each of the control sites received bovine bone alone. The animals were sacrificed at 1 week (n = 4), 2 weeks (n = 3) and 4 weeks (n = 3). Biopsy samples were examined histomorphometrically by light microscopy, and expression of vascular endothelial growth factor (VEGF) was determined by immunohistochemical staining.

RESULTS

At all experimental time points, immunostaining intensity for VEGF was consistently higher in the experimental group than in the control group. However, the differences between the control group and the experimental group were not statistically significant in the histomorphometrical and immunohistochemical examinations.

CONCLUSIONS

The results of this study suggest that PRF may increase the number of marrow cells. However, PRF along with xenogenic bone substitutes does not show a significant effect on bony regeneration. Further large-scale studies are needed to confirm our results.

Clinical evaluation of use of platelet rich plasma in bone healing

BACKGROUND

Tooth extraction is performed for a wide variety of reasons as we know. Several techniques aiming at enhancing the regeneration process in the extraction socket have been adopted such as filling the socket with autogenous bone grafts or bone substitutes. We know platelets play a central role in hemostasis and healing processes but relative contradictory effect of platelet in bone regenerating capacity have been published in different in vitro and in vivo studies.

METHOD

To explore this we used platelet-rich plasma (PRP) (autogenous) alone in empty extraction socket of bilateral impacted mandibular third molars. For that we selected five patients having bilateral impacted teeth. Out of two sockets one was used as intervention by filling with PRP and the other was allowed to heal without PRP. All patients were followed for clinical and radiological evaluation by using digital OPG view after 1 week, 1, 2 and 4 months period.

RESULT AND CONCLUSION

PRP enhanced the osteogenic response in initial bone healing at 1 month duration but there was no added benefit in late bone healing at 4 months period compared in both intervention and control groups. However PRP significantly improved the soft tissue healing in PRP treated sites compared to control group.

Increased vascularization during early healing after biologic augmentation in repair of chronic rotator cuff tears using autologous leukocyte- and platelet-rich fibrin (L-PRF): a prospective randomized controlled pilot trial

HYPOTHESIS

We hypothesized that arthroscopic rotator cuff repairs using leukocyte- and platelet-rich fibrin (L-PRF) in a standardized, modified protocol is technically feasible and results in a higher vascularization response and watertight healing rate during early healing.

METHODS

Twenty patients with chronic rotator cuff tears were randomly assigned to 2 treatment groups. In the test group (N = 10), L-PRF was added in between the tendon and the bone during arthroscopic rotator cuff repair. The second group served as control (N = 10). They received the same arthroscopic treatment without the use of L-PRF. We used a double-row tension band technique. Clinical examinations including subjective shoulder value, visual analog scale, Constant, and Simple Shoulder Test scores and measurement of the vascularization with power Doppler ultrasonography were made at 6 and 12 weeks.

RESULTS

There have been no postoperative complications. At 6 and 12 weeks, there was no significant difference in the clinical scores between the test and the control groups. The mean vascularization index of the surgical tendon-to-bone insertions was always significantly higher in the L-PRF group than in the contralateral healthy shoulders at 6 and 12 weeks (P = .0001). Whereas the L-PRF group showed a higher vascularization compared with the control group at 6 weeks (P = .001), there was no difference after 12 weeks of follow-up (P = .889). Watertight healing was obtained in 89% of the repaired cuffs.

DISCUSSION/CONCLUSIONS

Arthroscopic rotator cuff repair with the application of L-PRF is technically feasible and yields higher early vascularization. Increased vascularization may potentially predispose to an increased and earlier cellular response and an increased healing rate.

Minimally invasive sinus augmentation using ultrasonic piezoelectric vibration and hydraulic pressure: a multicenter retrospective study

PURPOSE

The purpose of this study was to evaluate the success rate of implants and vertical bone gain of edentulous posterior maxilla using ultrasonic piezoelectric vibration and hydraulic pressure, namely the hydrodynamic piezoelectric internal sinus elevation (HPISE) technique through a crestal approach.

MATERIALS AND METHODS

A total of 250 maxillary sinuses were augmented using HPISE and 353 implants (averaging 11.8 mm in length and 4.5 mm in diameter), with 12 different systems, were placed simultaneously with or without additional bone grafting. Plain radiograms and cone beam computed tomograms were taken in all patients to evaluate sinus augmentation.

RESULTS

Membrane perforation was recorded at 10 of the 353 implant sites. The perforation rate was 2.83%. The total success rate of implantation was 97.2% after an average of 69.3 weeks of loading.

CONCLUSION

The crestally approached sinus augmentation using ultrasonic piezoelectric vibration and hydraulic pressure is an additional method of maxillary sinus augmentation.

The effect of platelet rich fibrin on growth factor levels in urethral repair

AIM

Platelet rich fibrin (PRF) is an autologous source of growth factors and promotes wound healing. An experimental study was performed to evaluate the effect of PRF on growth factor levels in urethral repair.

MATERIALS AND METHODS

Eighteen Wistar albino rats were included in the study. Rats were allocated in three groups (n:6): control (CG), sham (SG), and PRF (PRFG). In SG, a 5 mm vertical incision was performed in the penile urethra and repaired with 10/0 Vicryl® under a microscope. In PRFG, during the urethral repair as described in SG, 1 cc of blood was sampled from each rat and centrifuged for 10 minutes at 2400 rpm. PRF obtained from the centrifugation was placed on the repair site during closure. Penile urethras were sampled 24 hours after PRF application in PRFG and after urethral repair in SG. Transforming growth factor beta receptor (TGF-β-R-CD105), vascular endothelial growth factor (VEGF) and its receptor (VEGF-R), as well as endothelial growth factor receptor (EGFR), were evaluated in subepithelia of the penile skin and urethra. Groups were compared for growth factor levels and growth factor receptor expression with the Kruskal Wallis test.

RESULTS

TGF-β-R levels were significantly decreased in SG when compared to CG (p<0.05). In PRFG, TGF-β-R was increased in both subepithelia of penile skin and urethra with respect to SG (p<0.05). When VEGF levels and its receptor expression were compared between SG and PRFG, VEGF levels were found to be increased in penile skin subepithelium, whereas VEGF-R expressions were decreased in urethral subepithelia in PRFG (p<0.05). There was no difference between groups for EGFR levels (p>0.05).

CONCLUSION

Use of PRF after urethral repair increases TGF-β-R and VEGF expressions in urethral tissue. PRF can be considered as an alternative measure to improve the success of urethral repair.

Effects of platelet-poor plasma, platelet-rich plasma, and platelet-rich fibrin on healing of extraction sockets with buccal dehiscence in dogs

Alveolar bone resorption generally occurs during healing after tooth extraction. This study aimed to evaluate the effects of platelet-poor plasma (PPP), platelet-rich plasma (PRP), and platelet-rich fibrin (PRF) on healing in a ridge-augmentation model of the canine socket with dehiscence of the buccal wall. The third mandibular premolars of 12 beagle dogs were extracted and a 3 mm buccal dehiscence from the alveolar crest to the buccal wall of the extraction socket was created. These sockets were then divided into four groups on the basis of the material used to fill the sockets: PPP, PRP, PRF, and control (no graft material) groups. Results were evaluated at 4 and 8 weeks after surgery. The ultrastructural morphology and constructs of each blood product were studied by a scanning electron microscope (SEM) or calculating concentrations of platelets, fibrinogen, platelet-derived growth factor, and transforming growth factor-β. A total of five microcomputed tomography images of specimens were selected for measurement, and the area occupied by the newly formed bone as well as the horizontal bone width were measured. Moreover, decalcified tissue specimens from each defect were analyzed histologically. The median area of new bone at 4 and 8 weeks and median horizontal bone width at 8 weeks were the highest in the PPP group. However, bone maturation in the PRF and the PRP groups was more progressed than that in the PPP and control groups. By SEM findings, the PRF group showed a more highly condensed fibrin fiber network that was regularly arranged when compared with the PPP and PRP groups. The growth factors released from platelets in PRP indicated higher concentrations than that in PRF. Under more severe conditions for bone formation, as in this experiment, the growth factors released from platelets had a negative effect on bone formation. This study showed that PPP is an effective material for the preservation of sockets with buccal dehiscence.

Management of chronic luxated central incisor with hopeless prognosis

Traumatic injuries are the most studied yet most challenging for a dentist. Extrusive luxation injuries are usually managed by repositioning tooth in the original position and pulp sensibility is evaluated at regular periodic intervals. However, when injuries are chronic, tooth is necrotic with compromised periodontal support, treatment is a challenge. Intentional replantation utilizing growth factors in fibrin rich network of platelet rich fibrin can be a treatment modality in such patients where other restorative modalities to establish function-esthetics rehabilitation is not possible.

Effect of leukocyte- and platelet-rich fibrin (L-PRF) on bone regeneration: a study in rabbits

BACKGROUND

The positive effect of leukocyte- and platelet-rich fibrin (L-PRF) on osteogenesis has been widely described in vitro. However, clinical and preclinical studies are very little and controversial in demonstrating a significant beneficial effect of L-PRF in bone regeneration.

PURPOSE

The goal of the present study was to compare the potential effect of L-PRF in a standardized model.

MATERIALS AND METHODS

A total of 72 hemispheres were implanted on the calvaria of 18 rabbits and filled with three different space fillers: L-PRF, bovine hydroxyapatite (BHA), BHA + L-PRF, and an empty hemisphere was used as control. Six rabbits were sacrificed at three distinct time points: 1 week, 5 weeks, and 12 weeks. Histological and histomorphometrical analyses were carried out.

RESULTS

At the early phase of bone regeneration (1 week), from a descriptive analysis, a higher proportion of connective tissue colonized the regeneration chamber in the two groups containing BHA particles. Nevertheless, no statistical differences were found within the four groups in terms of bone quantity and quality at each timepoint (p = .3623).

CONCLUSIONS

According to the present study, L-PRF does not seem to provide any additional effect on the kinetics, quality, and quantity of bone in the present model of guided bone regeneration.

Role of Platelet rich fibrin in wound healing: A critical review

AIM

The aim is to review and discuss the strategies available for use of platelet rich fibrin as healing aid in dentistry.

BACKGROUND

Platelet rich fibrin (PRF) is a fibrin matrix in which platelet cytokines, growth factors, and cells are trapped and may be released after a certain time and that can serve as a resorbable membrane. Choukroun and his associates were amongst the pioneers for using PRF protocol in oral and maxillofacial surgery to improve bone healing in implant dentistry. Autologous PRF is considered to be a healing biomaterial, and presently, studies have shown its application in various disciplines of dentistry.

MATERIALS AND METHODS

By using specific keywords, electronic search of scientific papers was carried out on the entire PubMed database with custom range of 5 years. The electronic search yielded 302 papers; based on inclusion and exclusion criteria which were specifically predetermined, 72 papers were identified as suitable to the inclusion criteria and the remaining 230 papers were excluded. After adding three more selected papers through hand search, full text of all the articles retrieved and review was done. By pooling the extracted data from selected papers, the reviewed data was synthesized.

CONCLUSION

Recently by showing good promising results with use of the PRF, it has proved to have a good prospect for its use as healing aid in various aspects of the dentistry.