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

Platelet-rich Fibrin: A Paradigm in Periodontal Therapy - A Systematic Review

Periodontal tissue regeneration has always been a challenge for the periodontists owing to its structural complexity. Although with tissue engineering as a growing multidisciplinary field, this aim has partially been fulfilled. In recent years, platelet-rich fibrin (PRF) has gained wide attention for its utilization as a biocompatible regenerative material not only in dental but also in medical fields. The following systematic review has gathered all the currently available in vitro, animal, and clinical studies utilizing PubMed electronic database from January 2006 to August 2016 highlighting PRF for soft and hard tissue regeneration and/or wound healing. Although results are encouraging but require further validation from clinical studies to justify the potential role of PRF in periodontal regeneration so that this relatively inexpensive autologous biomaterial can be utilized at a wider scale.

Platelet-rich fibrin-based matrices to improve angiogenesis in an in vitro co-culture model for bone tissue engineering

In the context of prevascularization strategies for tissue‐engineering purposes, co‐culture systems consisting of outgrowth endothelial cells (OECs) and primary osteoblasts (pOBs) have been established as a promising in vitro tool to study regeneration mechanisms and to identify factors that might positively influence repair processes such as wound healing or angiogenesis. The development of autologous injectable platelet‐rich fibrin (PRF), which can be generated from peripheral blood in a minimal invasive procedure, fulfils several requirements for clinically applicable cell‐based tissue‐engineering strategies. During this study, the established co‐culture system of OECs and pOBs was mixed with injectable PRF and was cultivated in vitro for 24 h or 7 days. The aim of this study was to analyse whether PRF might have a positive effect on wound healing processes and angiogenic activation of OECs in the co‐culture with regard to proinflammatory factors, adhesion molecules and proangiogenic growth factor expression. Histological cell detection revealed the formation of lumina and microvessel‐like structures in the PRF/co‐culture complexes after 7 days of complex cultivation. Interestingly, the angiogenic activation of OECs was accompanied by an upregulation of wound healing‐associated factors, as well as by a higher expression of the proangiogenic factor vascular endothelial growth factor, which was evaluated both on the mRNA level as well as on the protein level. Thus, PRF might positively influence wound healing processes, in particular angiogenesis, in the in vitro co‐culture, making autologous PRF‐based matrices a beneficial therapeutic tool for tissue‐engineering purposes by simply profiting from the PRF, which contains blood plasma, platelets and leukocytes.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Autologous Platelet-Rich Fibrin in the Treatment of 3-Wall Intrabony Defects in Aggressive Periodontitis: A Randomized Controlled Clinical Trial

BACKGROUND

Platelet-rich fibrin (PRF) has recently been applied in osseous regeneration. The aim of the present study is to explore the efficacy of PRF in treatment of intrabony defects (IBDs) in aggressive periodontitis.

METHODS

Fifty-four IBDs in 17 patients were treated either with autologous PRF with open flap debridement (OFD) or OFD alone. Clinical and radiologic parameters such as probing depth (PD), clinical attachment level (CAL), IBD depth, and percentage defect change were recorded at baseline and 9 months postoperatively.

RESULTS

Mean PD reduction and mean CAL gain were significantly greater in PRF compared with the control group. Furthermore, a significantly greater percentage of mean bone defect change was found in the PRF group.

CONCLUSION

Within the limits of the present study, there is greater bone fill at sites treated with PRF with conventional OFD than conventional OFD alone.

Platelet-Rich Fibrin Facilitates Rabbit Meniscal Repair by Promoting Meniscocytes Proliferation, Migration, and Extracellular Matrix Synthesis

Although platelet-rich fibrin (PRF) has been used in clinical practice for some time, to date, few studies reveal its role as a bioactive scaffold in facilitating meniscal repair. Here, the positive anabolic effects of PRF on meniscocytes harvested from the primary culture of a rabbit meniscus were revealed. The rabbit meniscocytes were cultured with different concentrations of PRF-conditioned medium, and were evaluated for their ability to stimulate cell migration, proliferation, and extracellular matrix formation. In vivo, meniscal defects were created via an established rabbit animal model and were evaluated by a histology-based four-stage scoring system to validate the treatment outcome three months postoperatively. The in vitro results showed that PRF could induce cellular migration and promote proliferation and meniscocyte extracellular matrix (ECM) synthesis of cultured meniscocytes. In addition, PRF increased the formation and deposition of cartilaginous matrix produced by cultured meniscocytes. Morphological and histological evaluations demonstrated that PRF could facilitate rabbit meniscal repair. The data highlight the potential utility of using PRF in augmenting the healing of meniscal injuries. These advantages would benefit clinical translation, and are a potential new treatment strategy for meniscal repair.

Clinical Comparison of the Subepithelial Connective Tissue versus Platelet-Rich Fibrin for the Multiple Gingival Recession Coverage on Anterior Teeth Using the Tunneling Technique

The aim of this study was to evaluate and compare, clinically, the efficiency of the subepithelial connective tissue graft (SCTG) and platelet-rich fibrin (L-PRF) using the tunnel technique to cover the multiple gingival recessions on anterior teeth, in the same patient. Within the limits of this study, we conclude that both SCTG and L-PRF proved to be reliable options for the treatment of gingival recessions, efficiently supporting the biological and aesthetic demand, stimulating the periodontal tissues' health, and bringing reliable and highly predictable results.

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

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

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

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

Introduction

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

Presentation of case

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

Discussion

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

Conclusion

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

Clinical and Microcomputed Topography Evaluation of the Concentrated Growth Factors as a Sole Material in a Cystic Bony Defect in Alveolar Bone Followed by Dental Implantation: A Case Report

Concentrated growth factors (CGFs) can be used to enhance wound healing. This case report describes a short-term effect of CGF grafting followed by implant placement in a cystic bony defect within the mandible. Healing conditions were monitored by 2 implant-related surgeries, radiographs, and a microcomputed topography examination. Continuous increase of radiopacity in radiographs was noticed till 6 months after grafting. Bone core specimen was taken at 3.5 months after grafting, and percent bone volume reached 32.7% analyzed by microcomputed topography. In conclusion, the present case showed bone regeneration in the cystic bony defect grafted by CGFs alone.

Use of Leukocyte- and Platelet-Rich Fibrin in the Treatment of Medication-Related Osteonecrosis of the Jaws

Lesions associated with medication-related osteonecrosis of the jaws (MRONJ) are refractory to different treatment approaches. Hence, auxiliary approaches capable of improving patient outcomes should be explored. Leukocyte- and platelet-rich fibrin (LPRF) is a second-generation platelet concentrate (natural autologous fibrin matrix). It shows anti-infectious activity through immune regulation and accelerates the angiogenesis and multiplication of fibroblasts and osteoblasts; in consequence, it stimulates soft tissue healing and prevents exposure of the alveolar bone in the oral cavity. This report describes 2 cases involving women with breast cancer who were being treated with zoledronic acid and exhibited advanced MRONJ. In case 1, MRONJ developed in the maxilla after dental extraction; in case 2, it was assumed that MRONJ arose spontaneously in the mandible because no other risk factors could be detected. These cases were managed with surgical resection of the necrotic bone followed by placement of an LPRF membrane. Complete wound healing and intact mucosal cover were achieved. At clinical and tomographic follow-up after 2 years, there were no oral lesions or complaints. Therefore, this could be a noninvasive, quick, and alternative approach to manage bone exposure. The LPRF membrane contributes to a successful outcome and acts as a physical barrier against micro-organisms, thus preventing secondary infections.

Effect of Autologous Platelet Rich Fibrin in Human Mandibular Molar Grade II Furcation Defects- A Randomized Clinical Trial

INTRODUCTION

The Furcation of multirooted teeth is difficult region to gain access for treatment due to their complex anatomy. Modifications have been made in the periodontal instrument armamentarium to facilitate treatment of furcations. Moreover, many new materials have been introduced to attempt regeneration in the furcation defects.

AIM

This study evaluated the role of Platelet Rich Fibrin (PRF) in comparison with allograft and Guided Tissue Regeneration (GTR) in the treatment of Grade II mandibular molar furcations.

MATERIALS AND METHODS

This was a parallel arm prospective randomized, interventional trial (NCT 02430519) conducted on 22 patients, with Grade II mandibular furcation defects. Patients were divided into two equal groups. Group A, were treated by the placement of PRF as a graft and as a membrane while in Group B, the defects were treated by the placement of allograft and Healiguide collagen membrane. Clinical parameters {Plaque Index (PI), Probing Depth (PD), Relative Vertical Clinical Attachment Level (RVCAL), Relative Horizontal Clinical Attachment Level (RHCAL), Gingival Marginal Level(GML), and amount of Bonefill using Radio-Visiography (RVGBF)}, were estimated at baseline and nine months postoperatively. Comparison between the groups was analysed by using independent sample t-test, whereas, paired t-test was used to assess the mean values within the groups.

RESULTS

The intergroup comparison for PI, PD, RHCAL, GML, was statistically not significant. Pertaining to RVCAL, there was a statistically significant difference at nine months (p-value=0.04) in Group A. Also, there was a statistically significant difference related to RVGBF (p-value=0.006) in Group A at nine months.

CONCLUSION

The efficacy of PRF should be ascertained by conducting more studies with a larger sample size, on a long term basis, in patients with molar Grade II furcation defects.

Use of platelet-rich fibrin in regenerative dentistry: a systematic review

OBJECTIVES

Research across many fields of medicine now points towards the clinical advantages of combining regenerative procedures with platelet-rich fibrin (PRF). This systematic review aimed to gather the extensive number of articles published to date on PRF in the dental field to better understand the clinical procedures where PRF may be utilized to enhance tissue/bone formation.

MATERIALS AND METHODS

Manuscripts were searched systematically until May 2016 and separated into the following categories: intrabony and furcation defect regeneration, extraction socket management, sinus lifting procedures, gingival recession treatment, and guided bone regeneration (GBR) including horizontal/vertical bone augmentation procedures. Only human randomized clinical trials were included for assessment.

RESULTS

In total, 35 articles were selected and divided accordingly (kappa = 0.94). Overall, the use of PRF has been most investigated in periodontology for the treatment of periodontal intrabony defects and gingival recessions where the majority of studies have demonstrated favorable results in soft tissue management and repair. Little to no randomized clinical trials were found for extraction socket management although PRF has been shown to significantly decrease by tenfold dry sockets of third molars. Very little to no data was available directly investigating the effects of PRF on new bone formation in GBR, horizontal/vertical bone augmentation procedures, treatment of peri-implantitis, and sinus lifting procedures.

CONCLUSIONS

Much investigation now supports the use of PRF for periodontal and soft tissue repair. Despite this, there remains a lack of well-conducted studies demonstrating convincingly the role of PRF during hard tissue bone regeneration. Future human randomized clinical studies evaluating the use of PRF on bone formation thus remain necessary.

CLINICAL RELEVANCE

PRF was shown to improve soft tissue generation and limit dimensional changes post-extraction, with little available data to date supporting its use in GBR.

The Effect of Platelet-Rich Fibrin, Calcium Sulfate Hemihydrate, Platelet-Rich Plasma and Resorbable Collagen on Soft Tissue Closure of Extraction Sites

Rapid and complete soft tissue healing after tooth extraction minimizes surgical complications and facilitates subsequent implant placement. We used four treatment methods and assessed changes in soft tissue socket closure following tooth extraction in humans. The effects of platelet-rich fibrin-calcium sulfate hemihydrate (PRF-CSH), platelet-rich plasma-calcium sulfate hemihydrate (PRP-CSH), a resorbable collagen dressing (RCD), and no grafting material were compared in a randomized, controlled pilot study with a blinded parallel design (N = 23). Patients with a hopeless tooth scheduled for extraction were randomly assigned to one of the four treatment groups. Socket measurements were obtained immediately after extraction and treatment, as well as after 21 days. There was a significant decrease in the total epithelialized external surface area of the extraction sockets in each group at all time points. However, there were no significant differences in soft tissue closure (p > 0.05) at any time point and PRF-CSH or PRP-CSH did not provide any additional benefit to enhance the soft tissue closure of extraction sockets compared with either RCD or sites without graft.

Histological evaluation of effectiveness of platelet-rich fibrin on healing of sinus membrane perforations: A preclinical animal study

The aim of this study was to evaluate the effectiveness of platelet-rich fibrin (PRF) in repairing of Schneiderian membrane perforations in rabbit maxillary sinus. A total of 42 female New Zealand rabbits were randomly divided into two groups. Symmetrical bony defects were created 1 cm in diameter and the sinus membranes were exposed. The Schneiderian membranes were elevated in both sinuses and each membrane was perforated with a 1 cm incision. No treatment was applied to the right perforations in both groups. Left-sided perforations were closed with collagen membrane in the first group and PRF membrane in the other group. Seven animals randomly selected from each group were sacrificed at weeks 1, 2 and 4 in order to be able to examine the amounts of lymphocytes, fibroblasts, veins, and collagen fibers in the area where the membranes were applied. Histological analyses showed that there were no statistically significant differences between the collagen membrane and the PRF membrane in the healing of sinus perforation area. PRF may be considered as an alternative application to collagen membrane in sinus membrane perforations.

Uncommon Odontogenic Orocutaneous Fistula of the Jaw Treated with Platelet-Rich Fibrin

Orocutaneous fistula (OCF) of dental origin is a relatively rare condition and continues to be a challenging diagnosis. Misdiagnosis of OCF usually leads to unnecessary and noneffective treatment. A 21-year-old male referred with a complaint of a lesion on the chin which was misdiagnosed as a carbuncle (lesion of nonodontogenic origin) by a physician. After radiological examination, there was a lesion around the apical region of right central incisor. These findings indicated a sinus tract associated with dental origin. After root canal treatment, apical surgery was performed and platelet-rich fibrin (PRF) was administered to the cavity of the lesion as a gel form to improve healing and also used as a membrane form to cut off the relation between infected area and the skin. All procedures were performed intraorally; no extraoral intervention was performed. Three months later, clinical and radiological examination showed total healing without scar formation. The key to successful treatment of OCF is accurate diagnosis. Additionally, the use of PRF after surgical interventions is an effective and innovative therapy to improve healing.

Evaluation of the Effect of Platelet-Rich Fibrin on Long Bone Healing: An Experimental Rat Model

Pseudoarthrosis, or nonunion, of the long bones is a challenging medical condition for orthopedic surgeons to treat. Therefore, healing enhancer materials are commonly used. The authors investigated whether platelet-rich fibrin accelerates long bone healing by comparing radiological and histological findings in a rat model of open femoral fracture. Platelet-rich fibrin is a current biomaterial that contains many growth factors and platelets. There are no studies in the literature investigating the effects of platelet-rich fibrin on fracture healing. Sixteen mature male rats were divided into 2 groups. In both groups, an open femoral fracture was created. The platelet-rich fibrin was obtained by centrifuging blood collected from the rats. Rats in the study group were treated with sterile platelet-rich fibrin, and those in the control group were administered saline. The rats were killed at the end of 4 weeks and examined histologically and radiologically. The radiographic and histological scores of the 2 groups differed significantly (P<.05). These results indicate that platelet-rich fibrin is an efficient biomaterial in fracture healing and that it increases the amount of osseous tissue formation. Platelet-rich fibrin does not cause an allergic reaction, is cost-effective, and is easy to obtain. Additional studies are necessary to determine whether platelet-rich fibrin accelerates the fracture healing process or induces a better quality of fracture healing. [Orthopedics. 2017; 40(3):e479-e484.].

Effect of platelet rich fibrin on edema and pain following third molar surgery: a split mouth control study

BACKGROUND

To evaluate the efficacy of platelet-rich fibrine (PRF) on postoperative edema and pain after impacted mandibular third molar surgery.

METHODS

The prospective study was comprised 30 patients who presented for the removal of bilateral impacted mandibular third molar teeth. After extraction, the sockets were filled with PRF or without PRF in the study and control groups, respectively. Postoperative edema was measured with a flexible tape measure by calculating the distance between several facial landmarks on postoperative days two and seven. Postoperative pain was evaluated with a line-type visual analogue scale (VAS) and a verbal scale (VRS). SPSS version 20.0 was used for data analysis.

RESULTS

Both groups recorded significant improvement compared to the baseline levels in almost all of the outcome variables. There was no statistically significant difference between the study and control groups (p > 0.05).

CONCLUSIONS

Using or not using PRF to reduce postoperative pain and edema in third molar surgery was equally successful.

TRIAL REGISTRATION

This study was retrospectively registered at the ISRCTN registry ( ISRCTN16849867 ) on 6 March 2017.

Recognition and management of palatogingival groove for tooth survival: a literature review

Palatogingival groove (PGG) is an anomaly in the maxillary anterior teeth, often accompanied by the area of bony destruction adjacent to the teeth with no carious or traumatic history. The hidden trap in the tooth can harbor plaque and bacteria, resulting in periodontal destruction with or without pulpal pathologic change. Related diseases can involve periodontal destruction, combined endodontic-periodontal lesions, or separate endodontic and periodontal lesions. Disease severity and prognosis related to PGG depend on several factors, including location, range, depth, and type of the groove. Several materials have been used and recommended for cases of extensive periodontal destruction from PGG to remove and block the inflammatory source and recover the health of surrounding periodontal tissues. Even in cases of severe periodontal destruction, several studies have reported favorable treatment outcomes with proper management. With new options in diagnosis and treatment, clinicians need a detailed understanding of the characteristics, treatment, and prognosis of PGG to successfully manage the condition.

Alveolar Ridge Preservation After Tooth Extraction with DFDBA and Platelet Concentrates: A Radiographic Retrospective Study

Objectives:

The purpose of this study was to evaluate vertical alveolar bone loss 3 months after tooth extraction when a technique of ridge preservation was applied using a particulate demineralized freeze-dried bone allograft 300 - 500 µm associated with platelet concentrates (platelet-rich-fibrin) in the form of gel and membranes.

Material and Methods:

A retrospective radiological clinical study was conducted on 56 patients for whom 95 extractions had been performed immediately followed by alveolar filling. Among the patients, 17 were smokers and 16 were provided with an immediate removable temporary prosthesis after extractions. Vertical bone loss was measured radiologically by panoramic X-ray before extractions and by a computed tomography scan 3 months after, at the level of mid-buccal bone wall, by two independent observers. For statistical analysis, Student’s t-test was performed to compare the mean bone loss between mono- and pluri-radicular teeth and to compare the mean bone loss between tobacco users versus non users and finally to compare the mean bone loss between individuals that had provisional removable prosthesis and those that had not.

Results:

Three months after tooth extraction, the mean of vertical loss of the mid-buccal bone wall was 0.72 (SD 0.71) mm (5.53% SD 5.19). No significant difference between bone loss at mono-radicular and pluri-radicular teeth (P = 0.982) was observed. There was no significant correlation between tobacco habits and bone loss (P = 0.2), nor between provisional removable prosthesis and bone loss (P = 0.786).

Conclusion:

These results indicate a good potential for the technique using Demineralized Freeze-Dried Bone Allograft 300 - 500 µm and platelet concentrates in alveolar bone preservation.

Evaluation of effectiveness of concentrated growth factor on osseointegration

BACKGROUND

Growth factor-containing products have been reported to increase implant stability and accelerate osseointegration. Concentrated growth factor (CGF) can be used for this purpose with the growth factors it contains. The aim of this study is to assess the effect of CGF on implant stability and osseointegration.

METHODS

Twelve patients with maxillary anterior toothless were included in the study. Implant cavities prepared in the study group were covered with CGF membrane before implant placement, but conventional implant placement was performed in the control group. Resonance frequency measurements were performed with the Osstell device intra-operatively, post-operatively, at the 1st week, and at the 4th week.

RESULTS

The mean ISQ values were found to be 79.40 ± 2.604 for the study group and 73.50 ± 5.226 for the control group at 1st week, 78.60 ± 3.136 for the study group and 73.45 ± 5.680 for the control group at 4th week. The differences between the groups were statistically significant (p < 0.05).

CONCLUSIONS

It was observed that the concentrated growth factor had positive effects on implant stabilization. The ISQ measurements at week 1 and week 4 were notably higher in the study group. Application of this material seems to accelerate osseointegration.

Crestal Approach to Sinus Floor Elevation for Atrophic Maxilla Using Platelet-Rich Fibrin as the Only Grafting Material: A 1-Year Prospective Study

PURPOSE

Platelet-rich fibrin (PRF) has been recently used as the sole grafting material in sinus floor elevation procedures. The aim of this prospective study was to measure the bone gain around the dental implant after using the crestal approach to sinus floor elevation using platelet-rich fibrin as the only grafting material in atrophic posterior maxillae with residual bone height <5 mm.

MATERIALS AND METHODS

Two different types of implants were used: hydroxyapatite (HA) and sandblasted acid-etched (SA) implants. Panoramic radiography and computed tomography were used to measure the endosinus bone gain.

RESULTS

Twenty-seven patients with 39 implants (19 HA and 20 SA) were included in this study. The mean residual bone measurements before surgery in the SA and HA groups were 2.85 and 2.68 mm, respectively. The mean average bone gains for 1 year in the SA and HA groups were 4.38 and 4.00 mm, respectively.

CONCLUSION

This prospective study showed that platelet-rich fibrin promoted endosinus bone gain when used as the grafting material in the crestal approach to sinus floor elevation.

Quantification of growth factors in different platelet concentrates

Concentrated growth factor (CGF), a new generation of platelet concentrate product, appears to have more abundant growth factors because of its special centrifugation process. However, there are few studies supporting this. This study was designed to evaluate the contents of major growth factors in CGF and compare them with those found in PRP (platelet-rich plasma) and PRF (platelet-rich fibrin). PRP, PRF, and CGF were obtained from the same samples of peripheral blood. Concentrations of five representative growth factors in platelets were measured with enzyme-linked immunosorbent assay (ELISA): platelet-derived growth factor-BB (PDGF-BB), transforming growth factor β-1 (TGF-β1), insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF). The results showed that the bFGF levels in CGF and PRF were significantly higher than that in activated PRP. For other growth factors, such as PDGF-BB, TGF-β1, IGF-1, and VEGF, the levels did not differ significantly among activated PRP, PRF, and CGF. Our findings extended the currently available data on the release and measurement of growth factors in CGF and other platelet gels. In future studies, we need more data to find the proper therapeutic doses for platelet concentrates suitable for different clinical applications.

Clinical and immunohistochemical performance of lyophilized platelet-rich fibrin (Ly-PRF) on tissue regeneration

BACKGROUND

Platelet-rich fibrin (PRF) has been widely used in oral implantology and other fields, but benefits of the fresh PRF (FPRF (fresh platelet-rich fibrin)) were consequently limited because of its short-term application. Thus, a protocol for the combination of PRF and lyophilization comes up in the present study to address the issue of PRF storage and delayed clinical application, which has little been reported in this field at home and abroad by now.

PURPOSE

The aim of the present study was to evaluate the applicability of lyophilized platelet-rich fibrin (Ly-PRF) used as the scaffold material for craniofacial tissue regeneration and to compare its biochemical properties with commonly used fresh PRF.

MATERIALS AND METHODS

Two volunteers with both genders were selected as the source of PRF and Ly-PRF samples. Macro- and micro-scopic appearance evaluation as well as immunohistochemical comparison were performed on PRF samples before and after freeze-drying at -196°C. The second experimental phase was to observe clinical performance when fresh and lyophilized PRF were applied in guided bone regeneration (GBR) operations in 39 patients losing teeth in the anterior maxillary region who required an oral implantation followed by labial bone grafting.

RESULTS

The conventional histological and transmission electron microscopy images showed the microstructure of Ly-PRF, which resembled a mesh containing apparently irregularly shaped platelets with less alpha-granule than fresh PRF in micro and a translucent membrane with less elasticity than fresh PRF in macro. Simultaneous immunohistological staining results showed positive expression of PDGF-BB, IL-1, IL-4, TNF, TGF-β₁ in both fresh and lyophilized PRF, while the expression of PDGF-BB, IL-1, TNF, TGF-β₁ has no statistical difference between them (P > .05) but that of IL-4 in Ly-PRF is statistically higher than in fresh PRF (P < .05). When applied in GBR operations, there were no significant differences between Ly-PRF and FPRF in factors of histological and clinical evaluations (i.e., color, swelling, bleeding of the mucosa, pain leveland, and remodeling of hard tissue) performed 3 days, 7 days, and 4 months after the surgery (P > .05).

CONCLUSIONS

This study strongly supports that lyophilization at -196°C does not largely influence the expression of bioactive factors, the microstructure of fibrinogen or the clinical effects of PRF.

Comparative Evaluation of Platelet-Rich Fibrin with Connective Tissue Grafts in the Treatment of Miller's Class I Gingival Recessions

Background:

One of the most common aesthetic problem encountered in the field of periodontology is gingival recession, which is, perceived by the patients as increase in length of teeth. The treatment of buccal gingival recession is a common requirement due to aesthetic concern or root sensitivity. This study was planned to evaluate the efficacy of PRF membrane compared to that of CTG in Miller's class I gingival recessions.

Materials and Methods:

32 sites with Miller's Class I gingival recessions, out of which 16 sites received PRF (test) and 16 sites received CTG (control). Each patient had undergone an initial periodontal treatment, including oral hygiene instructions, plaque control, and scaling and root planing, followed by re-evaluation. All clinical recordings; recession height, recession width, clinical attachment level, height of keratinized tissue, thickness of keratinized tissue, healing index and pain perception, were performed immediately before surgery (baseline) and after 6 months interval following periodontal surgery.

Results:

In the test group, significant improvement was seen in terms CAL, REC-HT, REC-WD, HKT and TKT from baseline to 6 months. In the control group, only significant improvement seen was in REC-HT and TKT from baseline to 6 months. Comparison of both Healing Index and VAS score was done and it showed no significant difference between test and the control group except VAS at 1 week.

Conclusion:

Though CTG is a gold standard procedure, PRF can be used as an alternative procedure by keeping patient's comfort and recognition in mind.

Use of platelet concentrates in oral and maxillofacial surgery: an overview

OBJECTIVE

To describe and provide a comprehensive overview on the development, use and efficacy of autologous platelet concentrates in different in vitro and in vivo studies focusing on oral and maxillofacial pathologies.

MATERIALS AND METHODS

Present work employs an extensive critical overview of the literature on the development and application of platelet concentrates.

RESULTS

Platelet concentrates are innovative endogenous therapeutic agents which gained a lot of interest in different medical and dental disciplines due to their potential ability to stimulate and increase regeneration of soft and hard tissues. The effect of platelet-derived products is considered to be a result of the high number of platelets which contain a wide range of growth factors. They are not just therapeutic products but autologous blood concentrates containing active molecules. The quality of platelet concentrates may vary according to the individual physical state of donors making it difficult to to compare the outcomes of their application. Although, there are many studies analyzing the properties of these biomaterials both in vivo and in vitro, a consensus regarding their efficacy still has to be reached.

CONCLUSION

Evidences described in the literature on the efficacy of platelet concentrates in procedures in oral and maxillofacial region are controversial and limited. In order to clarify the real advantages and priorities for the patients, when the blood-derived products are applied, further in vitro and in vivo research about the activity of PRP and PRF on the dental cells biology should be conducted.

Comparative Evaluation of the Efficacy of Platelet-rich Fibrin and Calcium Phosphosilicate Putty alone and in Combination in the Treatment of Intrabony Defects: A Randomized Clinical and Radiographic Study

Background:

Combination of platelet-rich fibrin (PRF) and bone substitutes for the treatment of intrabony pockets is based on sound biologic rationale. The present study aimed to explore the clinical and radiographic effectiveness of autologous PRF and calcium phosphosilicate (CPS) putty alone and in combination in treatment of intrabony defects.

Materials and Methods:

A total of 45 intrabony defects were selected and randomly divided into three groups. In Group I, mucoperiosteal flap elevation followed by placement of PRF was done. In Group II, mucoperiosteal flap elevation followed by placement of CPS putty was done. In Group III, mucoperiosteal flap elevation followed by placement of PRF and CPS putty was done. Clinical parameters such as gingival index (GI), pocket depth (PD), clinical attachment level (CAL), gingival marginal position and radiographic parameters such as bone fill, changes in crestal bone level, and defect depth resolution were recorded at baseline and after 6 months postoperatively.

Results:

Statistically significant changes in GI, PD reduction, CAL gain, defect fill, and defect depth resolution from baseline to 6 months were seen in all the three groups (P < 0.05). On intergroup comparison, no statistically significant changes were seen in all clinical parameters. However, the difference in defect fill and defect depth resolution between the Groups I and III and Group II and III was significant.

Conclusion:

Within limitations of study, combination of PRF and CPS putty showed a significant improvement in PD reduction, CAL gain, and bone fill.

Natural Tooth Pontic: An Instant Esthetic Option for Periodontally Compromised Teeth-A Case Series

Sudden tooth loss in the esthetic zone of the maxillary or mandibular anterior region can be due to trauma, periodontal disease, or endodontic failure. The treatment options for replacing the missing tooth can vary between removable prosthesis, tooth-supported prosthesis, and implant-supported prosthesis. Irrespective of the final treatment, the first line of management would be to provisionally restore the patient's esthetic appearance at the earliest, while functionally stabilizing the compromised arch. Using the patient's own natural tooth as a pontic offers the benefits of being the right size, shape, and color and provides exact repositioning in its original intraoral three-dimensional position. Additionally, using the patient's platelet concentrate (platelet rich fibrin) facilitates early wound healing and preservation of alveolar ridge shape following tooth extraction. The abutment teeth can also be preserved with minimal or no preparation, thus keeping the technique reversible, and can be completed at the chair side thereby avoiding laboratory costs. This helps the patient better tolerate the effect of tooth loss psychologically. The article describes a successful, immediate, and viable technique for rehabilitation of three different patients requiring replacement of a single periodontally compromised tooth in an esthetic region.

Single-Tooth Osteotomy Combined Wide Linear Corticotomy Under Local Anesthesia for Correcting Anterior Protrusion With Ectopically Erupted Canine

BACKGROUNDS

This article presents the alternative surgical treatments of both anterior protrusion by carrying out retraction on mandibular anterior fragment, meanwhile applying retraction force on maxilla anterior teeth and ectopically erupted canine with using platelet-rich fibrin (PRF).

METHODS

Anterior segmental osteotomy was combined with linear corticotomy under local anesthesia. The correction of right ectopic canine was achieved through 2 stages. First, dento-osseous osteotomy on palatal side was performed. Then second osteotomy with immediate manual repositioning of the canine with concomitant first premolar extraction was enhanced with PRF, which was prepared by centrifuging patient's blood, applied into buccal side of high canine during osteotomy. Mandibular retraction was accomplished by anterior segmental osteotomy.

RESULTS

Single-tooth osteotomy is a more effective surgical method for ankylosed or ectopically erupted tooth in orthodontic treatment. It can reduce the total orthodontic treatment time and root resorption, 1 common complication. Significant improved bone formation was seen with the addition of PRF on noncritical size defects in the animal model. It is reasonable to think that PRF can promote bone regeneration. So early bone formation also can reduce the complication such as postoperative infection.

CONCLUSIONS

As an alternative to anterior protrusion and ectopically erupted canine treatment, segmental osteotomy and corticotomy combined platelet-rich plasma can enhance orthodontic treatment outcome.

Radiological assessment of the PRF/BMSC efficacy in the treatment of aseptic nonunions: A retrospective study on 90 subjects

BACKGROUND

Nonunion is a major orthopaedic concern because of treatment difficulty, high costs and devastating effects on the patients' life quality. Therefore, there is interest in the use of bone substitutes and cell-based strategies to augment fracture repair. We aimed to verify if Platelet Rich Fibrin (PRF) added with bone marrow stromal cells (BMSC) was able to improve the reparative process in the aseptic nonunion, and to establish whether it was worthwhile with atrophic nonunion. The primary outcome was radiological union. As secondary endpoint, the healing time was assessed, and the radiological consolidation grade at each follow-up.

METHODS

We identified 113 subjects with tibia or femur nonunion and retrospectively created two groups. Group A was constituted by 56 subjects who underwent the standard procedure, i.e. Judet decortication with/out internal fixation devices, and opposite cortical homoplastic stick. In 57 patients, the standard procedure was modified by adding PRF and BMSC carried by homologous lyophilised bone chips (group B). The same surgeon performed all the operations. To our knowledge, no data are reported in the literature about such application. Since a "gold standard" for healing quantification does not exist, a new scoring radiological system was applied, at 1.5, 3, 6, 12 and 24 months after treatment.

RESULTS

At the final 24-month follow-up, the radiological union percentage was 94,12 in group B and 95,12% in group A. A decreased healing time was demonstrated in the presence of PRF/BMSC in comparison with the standard procedure. When we compared the radiological scores at each follow-up, we found that the PRF/BMSC combination significantly improved the consolidation grade at 1.5-, 3- and 6-month follow-up in femurs and at 1.5-month follow-up in tibiae. Furthermore, an improved consolidation grade was demonstrated in the atrophic subjects treated with adjuvants compared to atrophic patients treated with the standard procedure at 1.5-month follow-up.

CONCLUSIONS

This study supports the concept that the use of PRF/BMSC, during the standard procedure, is effective in shortening nonunion healing time. It could allow an early mobilization of patients, minimizing suffering, and could be an effective tool to reduce the health-care costs resulting from this issue.

LEVEL OF EVIDENCE

Therapeutic level III.

Effects of Platelet-Rich Plasma & Platelet-Rich Fibrin with and without Stromal Cell-Derived Factor-1 on Repairing Full-Thickness Cartilage Defects in Knees of Rabbits

BACKGROUND

The purpose of this study was to create biomaterial scaffolds like platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) containing stromal cell-derived factor-1 (SDF1) as a chemokine to induce hyaline cartilage regeneration of rabbit knee in a full thickness defect.

METHODS

We created a full thickness defect in the trochlear groove of thirty-six bilateral knees of eighteen mature male rabbits. The knees were randomly divided into six groups (group I: untreated control, group II: PRP, group III: PRF, group IV: Gelatin+SDF1, group V: PRP+SDF1, and group VI: PRF+SDF1). After four weeks, the tissue specimens were evaluated by macroscopic examination and histological grading, immunofluorescent staining for collagen type II, and analyzed for cartilage marker genes by real-time PCR. The data were compared using statistical methods (SPSS 20, Kruskal-Wallis test, Bonferroni post hoc test and P<0.05).

RESULTS

Macroscopic evaluations revealed that international cartilage repair society (ICRS) scores of the PRF+SDF1 group were higher than other groups. Microscopic analysis showed that the ICRS score of the PRP group was significantly lower than other groups. Immunofluorescent staining for collagen II demonstrated a remarkable distribution of type II collagen in the Gel+SDF1, PRP+SDF1 and PRF+SDF1 groups compared with other groups. Real-time PCR analysis revealed that mRNA expression of SOX9 and aggrecan were significantly greater in the PRF+SDF1, PRP+SDF1, Gel+SDF1 and PRF groups than the control group (P<0.05).

CONCLUSION

Our results indicate that implantation of PRF scaffold containing SDF1 led to the greatest evaluation scores of full-thickness lesions in rabbits.

Ridge Expansion by Flapless Split Crest and Immediate Implant Placement: Evolution of the Technique

Various treatment strategies and techniques have been proposed to perform alveolar bone augmentation; most common are guided bone regeneration, split crest, and autologous bone grafting. All of these techniques are reported to possess bone regenerative properties of osteoinduction and osteoconduction in relation to regenerated bone survival. Split crest resulted to be one of the most reliable bone augmentation techniques. In this study, we describe a new flapless-modified split crest technique on 4 patients to optimize the bone regeneration with bone augmentation implant insertion in 1 single stage. The rationale of this technique is to obtain a proper buccal cortex expansion preserving its vascular supply and avoiding periosteal elevation for better cortical bone preservation. The main advantages of this technique consist in a single surgical stage without donor sites, vascular periosteal preservation of vestibular cortical walls, preservation of alveolar bone height avoiding bone loss after implant kit drilling, and preservation of proper cortical thickness on both sides, thereby saving periosteal nourishment on the vestibular side. Indication for this technique could be extended to almost every implant insertion for alveolar height saving at drilling time for implant insertion, because of the alveolar crest shape.

Custom anatomic healing abutments

Dental implants with their increasing success rates and predictability of final outcome are fast becoming the treatment of choice for replacing missing teeth. Considering the success of immediate implant placement in reducing tissue loss and achieving good esthetic results, is making it a more popular treatment modality in implant dentistry. Understanding the management of gingival tissues in relation to implants to obtain maximum esthetics is of utmost importance. The use of provisional abutments and immediate temporization has a proven track record of their ability to produce optimal esthetics and to guide the tissue response during the healing phase. With careful patient selection and execution, customized healing abutments can provide an effective method to enhance the esthetic and emergence profile for anterior implant restorations.

Platelet-Rich Fibrin and Soft Tissue Wound Healing: A Systematic Review

The growing multidisciplinary field of tissue engineering aims at predictably regenerating, enhancing, or replacing damaged or missing tissues for a variety of conditions caused by trauma, disease, and old age. One area of research that has gained tremendous awareness in recent years is that of platelet-rich fibrin (PRF), which has been utilized across a wide variety of medical fields for the regeneration of soft tissues. This systematic review gathered all the currently available in vitro, in vivo, and clinical literature utilizing PRF for soft tissue regeneration, augmentation, and/or wound healing. In total, 164 publications met the original search criteria, with a total of 48 publications meeting inclusion criteria (kappa score = 94%). These studies were divided into 7 in vitro, 11 in vivo, and 31 clinical studies. In summary, 6 out of 7 (85.7%) and 11 out of 11 (100%) of the in vitro and in vivo studies, respectively, demonstrated a statistically significant advantage for combining PRF to their regenerative therapies. Out of the remaining 31 clinical studies, a total of 8 reported the effects of PRF in a randomized clinical trial, with 5 additional studies (13 total) reporting appropriate controls. In those clinical studies, 9 out of the 13 studies (69.2%) demonstrated a statistically relevant positive outcome for the primary endpoints measured. In total, 18 studies (58% of clinical studies) reported positive wound-healing events associated with the use of PRF, despite using controls. Furthermore, 27 of the 31 clinical studies (87%) supported the use of PRF for soft tissue regeneration and wound healing for a variety of procedures in medicine and dentistry. In conclusion, the results from the present systematic review highlight the positive effects of PRF on wound healing after regenerative therapy for the management of various soft tissue defects found in medicine and dentistry.

Mandibular Degree II Furcation Defects Treatment With Platelet-Rich Fibrin and 1% Alendronate Gel Combination: A Randomized Controlled Clinical Trial

BACKGROUND

Different materials have been investigated for renewal of lost supporting periodontal structures and tested for furcation defect treatment. Platelet-rich fibrin (PRF) is a pool of growth-promoting factors and cytokines that promote bone regeneration and maturation of soft tissue. Alendronate (ALN), an influential member of the bisphosphonate group, is known to enhance osteoblastogenesis and inhibit osteoclastic bone resorption, thus promoting tissue regeneration. This randomized trial was done to assess effectiveness of PRF and 1% ALN gel combination in mandibular degree II furcation defect treatment in comparison with PRF and access therapy alone.

METHODS

Seventy-two mandibular molar furcation defects were treated with either access therapy alone (group 1), access therapy with PRF (group 2), or access therapy with PRF and 1% ALN (group 3). Plaque index, modified sulcus bleeding index, probing depth (PD), relative vertical attachment level (RVAL) and relative horizontal attachment level (RHAL), and intrabony defect depth were recorded at baseline and 9 months postoperatively. Radiographically, defect fill, assessed in percentage, was evaluated at baseline, before surgery, and 9 months post-therapy.

RESULTS

Group 3 showed greater PD reduction and RVAL and RHAL gain when compared with groups 1 and 2 postoperatively. Moreover, group 3 sites showed a significantly greater percentage of radiographic defect fill (56.01% ± 2.64%) when compared with group 2 (49.43% ± 3.70%) and group 1 (10.25% ± 3.66%) at 9 months.

CONCLUSIONS

Furcation defect treatment with autologous PRF combined with 1% ALN gel results in significant therapeutic outcomes when compared with PRF and access therapy alone. Combining ALN with PRF has potential for regeneration of furcation defects without any adverse effect on healing process.