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

Onlay platelet-rich fibrin membrane versus free gingival graft in increasing the width of keratinized mucosa around dental implants: A split-mouth randomized clinical study

Background. This study aimed to compare the use of the platelet-rich fibrin membrane (PRF) versus the free gingival graft (FGG) during the second stage of the dental implant to increase the amount of keratinized mucosa around dental implants. Methods. Fifteen patients with bilaterally missing teeth and deficient width of the keratinized mucosa (KM) were recruited for a spit-mouth randomized controlled trial. After implant placement on the control sides, onlay FGG was used, whereas, on the other side (study side), onlay PRF membranes were applied to augment the KM. One month and three months after augmentation, the increase in keratinized mucosa width, bone level around the implants, and soft tissue health were evaluated and compared. The shrinkage percentage was also calculated for both grafts. Results. There was a significant increase in the width of KM in the FGG and PRF groups; however, it was observed that FFG resulted in significantly better results than PRF, with no significant difference in peri-implant soft tissue health or bone level. Conclusion. Within the limitations of this study, it was concluded that the onlay PRF membrane could increase the keratinized mucosa width around dental implants with the advantages of a lower surgical time and less postoperative discomfort and pain for the patients in comparison to the FGG. However, FGG had a significantly higher ability to augment and increase keratinized mucosa around dental implants.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

PROSPERO Identifier: CRD42021278542.

Collagen wrapping and local platelet-rich fibrin do not improve the survival rates of ACL repair with dynamic intraligamentary stabilization: a retrospective case series after ≥5 years postoperatively

PURPOSE

Anterior cruciate ligament (ACL) repair has been recommended as a treatment principle for ACL tears. Several authors have advocated a potential role for primary repair techniques in the ACL decision tree. However, long-term results have been controversial. This study aims to determine the survival of the primarily repaired ACL after dynamic intraligamentary stabilization (DIS) with and without augmentation.

METHODS

Between 2014 and 2019, 102 patients with isolated proximal ACL ruptures underwent DIS repair within 21 days from injury and were available for follow-up either clinically or telephonically after ≥5 years postoperatively. In 45 cases, DIS repair was augmented with collagen fleece wrapping, platelet-rich fibrin (PRF) or both. Failure was defined as traumatic re-rupture or conversion to ACL reconstruction. The patients being available for physical examination underwent a.-p. stability measurement with a KT-1000 device. Functional outcome was measured with the IKDC, Tegner and Lysholm scores. Kaplan-Meier survival analysis, Log-Rank Test and Binominal logistic regression were performed.

RESULTS

After a minimum 5-year follow-up, 71/102 (69.6%) DIS repairs were not re-reptured and clinically and/or subjectively stable. Augmentation did not improve survival rates (p = 0.812). The identified factors influencing failure were a younger age and a pre-injury Tegner activity level of ≥7. 95.7% of those patients with an intact ACL repair had normal or near normal knee function based on the IKDC scoring system.

CONCLUSIONS

The 5-year overall survival rate of DIS was 69.6%. Collagen fleece wrapping and local PRF application did not improve survival. Patients not suffering failure of repair demonstrated high satisfaction. Nevertheless, the results are inferior to those of established ACL reconstruction procedures.

LEVEL OF EVIDENCE

Case series, Level IV.

Effect of Sinus Floor Augmentation with Platelet-Rich Fibrin Versus Allogeneic Bone Graft on Stability of One-Stage Dental Implants: A Split-Mouth Randomized Clinical Trial

Rehabilitation of an edentulous posterior maxilla with dental implants is challenging, and sinus floor augmentation could be considered as an important surgical procedure for bone augmentation in this region before implant placement. Platelet-rich fibrin (PRF) is a new-generation platelet concentrate with simplified processing: its application in sinus floor augmentation has been widely investigated in literature. However, the biological properties and actual efficacy of this product remain controversial. This study assessed the effect of sinus floor augmentation with PRF versus freeze-dried bone allograft (FDBA) on stability of one-stage dental implants. This split-mouth randomized clinical trial evaluated 10 patients who required bilateral sinus floor augmentation. PRF and L-PRF membrane were used in one quadrant while FDBA and collagen membrane were used in the other quadrant. Implant stability was assessed by resonance frequency analysis (RFA) immediately, and 2, 4, and 6 months after implant placement. The implant stability quotient (ISQ) was compared over time and between the two groups using repeated measures ANOVA and independent sample t-test. The mean ISQ significantly increased over time in both groups (p < 0.001). The increase was greater in the PRF group (p < 0.05). Within the limitations of this study, PRF yielded superior results compared with FDBA regarding the stability of one-stage dental implants.

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

OBJECTIVES

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Treatment of Necrotic Anterior and Posterior Teeth with Regenerative Endodontic Procedures Using PRF as a Scaffold: A Retrospective Study

We assessed the impact of regenerative endodontic procedures (REP) using a platelet-rich fibrin (PRF) scaffold on necrotic immature permanent anterior and posterior teeth based on the following parameters: periapical healing, changes in root development, and associations between increases in the radiographic root area (RRA), and degree of root to apical closure. The study included 50 teeth consisting of 57 roots (36 anterior and 21 posterior) treated between 2017 and 2019, with an average follow-up of two years. Complete periapical healing was achieved in 91.2% teeth, and uncertain healing was achieved in 8.8%. RRA increased in 95% of teeth and root lengthening was achieved in 86% teeth (without any mutual effect). Apical closure was significantly associated with tooth location (89% and 30% of the posterior and anterior roots, respectively). Trauma was the most common aetiology of necrotic anterior teeth, whereas caries was the only aetiology of necrotic posterior teeth. REP using PRF scaffold achieved a high success rate for periapical healing and root maturation in both anterior and posterior necrotic immature teeth. The favourable results obtained in posterior teeth may encourage the use of REP for treating necrotic immature permanent posterior teeth.

Platelet-rich derivatives for accelerating the rate of orthodontic tooth movement - a systematic review and meta-analysis

Objective:

The aim of this systematic review and meta-analysis was to report on the effects of using platelet-rich derivatives on the rate of tooth movement.

Material and Methods:

Both electronic and manual searches were performed with specific eligibility criteria based on population, intervention, comparison, outcome, and study design. Risk of bias (RoB) assessment was done using the Cochrane RoB tool 2, the data were pooled and analyzed using review manager 4.5, and certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. Two independent reviewers performed the study selection, data extraction, and analysis. Nine studies were included for qualitative analysis and two of them were subjected to meta-analysis.

Results:

The standard mean difference for the rate of canine distal movement with platelet-rich derivatives was not significantly higher than controls at any of the time intervals (P > 0.0001). Rotation of canines, molar mesialization, and pain scores were not affected by the administration of platelet-rich derivatives for accelerating tooth movement. A moderate to high RoB was noted in the included studies and the certainty of the available evidence as assessed by the GRADE approach was moderate.

Conclusion:

The included studies presented with high heterogeneity and more high-quality studies with strict protocols are needed. Even though individual studies report significant acceleration of tooth movement following administration of PR derivatives, moderate certainty of evidence suggests no acceleratory effect on tooth movement.

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

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

Biomaterial scaffolds for clinical procedures in endodontic regeneration

Regenerative endodontic procedures have been rapidly evolving over the past two decades and are employed extensively in clinical endodontics. These procedures have been perceived as valuable adjuvants to conventional strategies in the treatment of necrotic immature permanent teeth that were deemed to have poor prognosis. As a component biological triad of tissue engineering (i.e., stem cells, growth factors and scaffolds), biomaterial scaffolds have demonstrated clinical potential as an armamentarium in regenerative endodontic procedures and achieved remarkable advancements. The aim of the present review is to provide a broad overview of biomaterials employed for scaffolding in regenerative endodontics. The favorable properties and limitations of biomaterials organized in naturally derived, host-derived and synthetic material categories were discussed. Preclinical and clinical studies published over the past five years on the performance of biomaterial scaffolds, as well as current challenges and future perspectives for the application of biomaterials for scaffolding and clinical evaluation of biomaterial scaffolds in regenerative endodontic procedures were addressed in depth.

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Overview of biomaterials for scaffolding in regenerative endodontics are presented.

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Findings of preclinical and clinical studies on the performance of biomaterial scaffolds are summarized.

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Challenges and future prospects in biomaterial scaffolds are discussed.

The Effect of Platelet-Rich Fibrin and Hyaluronic Acid on Perforation of Nasal Septum

BACKGROUND

Conservative approaches and surgical methods have been tried for the treatment of nasal septum perforations (NSPs), but a satisfactory method has not yet been determined.

OBJECTIVE

Our study aimed to investigate the effect of platelet-rich fibrin (PRF) and hyaluronic acid (HA) in repairing NSPs, which were experimentally created in rabbit septum.

METHODS

A total of 36 white New Zealand rabbits were included in the study. Perforations measuring 0.7 × 0.7 cm were created in their nasal septa. No additional intervention was made to the control group, which was the first group. For the second, third, and fourth groups, respectively, HA, PRF, and HA + PRF were used in the NSP region. Macroscopic and histopathological evaluations were performed after 40 days.

RESULTS

In the first group, closure was observed in none of the rabbits' NSPs. In the second group, 6 rabbits (66.7%) had full closure in their NSPs. In the third group, the NSP of 6 rabbits (66.7%) was completely closed. In the fourth group, the NSP of 7 rabbits (77.8%) had full closure.

CONCLUSION

Statistically significant closure was achieved with PRF and/or HA in rabbits in which NSP was established. These materials can be used to increase the likelihood of perforations closing.

Platelet-Rich Fibrin in Fat Grafts for Facial Lipofilling: A Randomized, Controlled Split-Face Clinical Trial

Objective

Previous studies have reported that platelet-rich fibrin (PRF) may enhance the efficacy of fat grafts in facial lipofilling. However, these studies either lacked objective data or were not randomized, controlled trials. Thus, we aimed to objectively evaluate the efficacy of PRF in facial lipofilling.

Methods

A controlled, split-face, randomized trial (January 2018 to May 2019) based on 18 patients who underwent fat grafts for bilateral temple lipofilling was performed. Each patient received a combination of an autologous fat graft and PRF on one side and a fat graft combined with an equal volume of saline on the other side. The effects of PRF were evaluated by comparing the remaining bilateral fat graft volumes through a digital three-dimensional reconstruction technique. Improvements in the appearance and recovery time of each temple were assessed by both a surgeon and patients who were blinded to the treatment assignment. Complications were also recorded.

Results

Bilateral temple lipofilling showed no evidence of fat embolism, vascular/nerve injury, infection, massive edema, or prolonged bruising. Three-dimensional reconstruction data and the assessments from both the surgeon and patients revealed no significant differences in fat graft retention volume between the PRF-positive and PRF-negative lipofilling groups. However, recovery time in the PRF-positive lipofilling sites was significantly shortened compared with that of the PRF-negative lipofilling sites.

Conclusion

Facial filling with autologous fat grafts is effective and safe. Our results show that PRF does not markedly improve fat graft volume retention in the temple but significantly reduces postoperative recovery time.

Trial Registration Number

ChiCTR2100053663.

Does zinc oxide nanoparticles potentiate the regenerative effect of platelet-rich fibrin in healing of critical bone defect in rabbits?

Background

Many encouraging studies confirmed the ability of Zinc Oxide Nanoparticles (ZnONPs) in accelerating bone growth and mineralization. The use of Platelet Rich-Fibrin (PRF) as a sole filling material for large segmental bone defects remains questionable. The objectives are to investigate the regenerative efficacy of autologous Platelet Rich-Fibrin (PRF) and Zinc Oxide Nanoparticles (ZnONPs) in repairing large segmental bone ulnar defects in a randomized controlled study in rabbits using computed tomographic interpretations. A 12 mm critical size defect was surgically induced in the ulna of 30 rabbits (n = 10/ group). In the control group, the defect was left empty. In the PRF group, the defect is filled with PRF. In the PRF/ZnONPs group, the defect is filled with PRF that was inoculated with 0.1 ml of 0.2% ZnONPs. Radiologic healing capacity was evaluated at the first, second, and third postoperative months.

Results

Statistical analysis showed significant differences in the radiologic healing scores between the groups (P = 0.000–0.0001) at all-time points (P = 0.000–0.047) during the study.

Conclusion

Rabbits in the PRF/ZnONPs group showed the highest appreciable bone quality and quantity followed by the PRF group with high quantity but low bone quality meanwhile, rabbits in the control group showed minimal quantity but medium bone quality. Interestingly, the addition of ZnONPs to PRF can accelerate the healing of ulnar critical-size defects in rabbits.

Sinus Lift Associated with Leucocyte-Platelet-Rich Fibrin (Second Generation) for Bone Gain: A Systematic Review

The purpose of this systematic review was to analyze sinus lifting procedures and to compare the efficiency of this treatment associated with the second generation of platelet-rich fibrin related to its effects on bone gain and to clarify the regenerative efficacy in sinus lift procedure, whether alone or as a coadjutant to other bone graft materials. The PICOT question was, “In clinical studies with patients needing a maxillary sinus lift (P), does the use of PRF either alone (I) or in conjunction with other biomaterials (C) improve the clinical outcome associated with bone gain and density (O), with at least three months of follow-up (T)?” An electronic search was conducted in the MEDLINE (PubMed), Science Direct, and Scopus databases through a search strategy. A total of 443 articles were obtained from the electronic database search. Sixteen articles met all criteria and were included in this review. Within the limitation of this study and interpreting the results carefully, it was suggested that a higher risk for implant failure after a sinus elevation might be seen in patients with residual bone ≤4 mm, and PRF application was effective, suggesting reducing the time needed for new bone formation.

Effect of Platelet-Rich Plasma on Autologous Chondrocyte Implantation for Chondral Defects: Results Using an In Vivo Rabbit Model

Background:

Articular cartilage repair remains challenging despite the availability of techniques, including autologous chondrocyte implantation (ACI) for repairing large cartilage defects. Platelet-rich plasma (PRP) therapy, a novel therapy focused on chondrocyte regeneration, needs to be investigated regarding its potential to improve the outcomes of ACI.

Purpose:

To examine the effect of PRP therapy on the outcomes of cartilage repair using the ACI procedure in a rabbit model of knee joint cartilage damage.

Study Design:

Controlled laboratory study.

Methods:

A total of 30 knees in 15 Japanese White rabbits (joint cartilage damage model) were divided into nontreatment (n = 7), PRP (n = 8), ACI (n = 7), and combined ACI and PRP (n = 8) groups. At 4 weeks and 12 weeks postoperatively, histological and visual examination of the surgical site was performed, and the regenerated cartilage and calcified bone areas were measured by imaging the specimens.

Results:

Pretransplantation evaluation in the cultured cartilage showed the histological properties of hyaline cartilage. At 4 weeks postoperatively, the regenerated cartilage area at the surgical site showed a larger safranin O–positive area in the ACI group (2.73 ± 4.46 mm²) than in the combined ACI and PRP group (1.71 ± 2.04 mm²). Calcified bone formation in the ACI group was relatively lower than that in the other groups. Cartilage repair failure occurred in all groups at 12 weeks postoperatively.

Conclusion:

The authors found no positive effects of PRP on the outcomes of ACI in a rabbit model. There was a smaller safranin O–positive region with the addition of PRP to ACI compared with ACI alone. In the subchondral bone, bone formation might have been promoted by PRP.

Clinical Relevance:

Administering PRP at the time of ACI may not have a positive effect and may have deleterious effects on cartilage engraftment and regeneration.

The feasibility of injectable PRF (I-PRF) for bone tissue engineering and its application in oral and maxillofacial reconstruction: From bench to chairside

Among all the biomaterials introduced in the field of bone tissue engineering, injectable platelet-rich fibrin (I-PRF) has recently gained considerable attention. I-PRF, as a rich source of biologically active molecules, is a potential candidate which can be easily obtained in bedside and constitutes several biological factors which can result in higher anti-bacterial, anti-inflammatory and regenerative capabilities. According to the studies evaluating the osteogenic efficacy of I-PRF, this biomaterial has exhibited favorable outcomes in terms of adhesion, differentiation, migration, proliferation and mineralization potential of stem cells. In addition, the injectability and ease-of-applicability of this biomaterial has led to its various clinical applications in the oral and maxillofacial bone regeneration such as ridge augmentation, sinus floor elevation, cleft palate reconstruction and so on. Furthermore, to enhance the clinical performance of I-PRF, albumin gel-PRF as a long-lasting material for long-term utilization has been recently introduced with a gradual increase in growth factor release pattern. This review provides a comprehensive approach to better evaluate the applicability of I-PRF by separately appraising its performance in in-vitro, in-vivo and clinical situations. The critical approach of this review toward the different production protocols and different physical and biological aspects of I-PRF can pave the way for future studies to better assess the efficacy of I-PRF in bone regeneration.

Fabrication and evaluation of Cs/PVP sponge containing platelet-rich fibrin as a wound healing accelerator: An in vitro and in vivo study

Despite significant advances in surgery and postoperative care, there are still challenges in the treatment of wounds. In the current study, a freeze-dried chitosan (Cs)/polyvinylpyrrolidone (PVP) sponges containing platelet-rich fibrin (PRF at 1, 1.5 and 2% w/v) for wound dressing application is fabricated and fully characterized. Addition of 1% w/v of PRF to Cs/PVP (CS/PVP/1PRF) sample significantly increased the tensile strength (from 0.147 ± 0.005 to 0.242 ± 0.001 MPa), elastic modulus (from 0.414 ± 0.014 to 0.611 ± 0.022 MPa) and strain at break (from 53.4 ± 0.9 to 61.83 ± 1.17%) compared to Cs sample, and was hence selected as the optimal sample. The antibacterial activity of Cs/PVP/1PRF sponge wound dressing against E. coli and S. aureus was confirmed to be effective. Enzyme-linked immunosorbent assays revealed that the release of both VEGF and PDGF-AB from PRF powder, as well as PDGF-AB from Cs/PVP/1PRF sample was time-independent, but the release of VEGF from Cs/PVP/1PRF sample increased significantly with time. According to MTT and CAM assays, the Cs/PVP/1PRF sample significantly increased proliferation and angiogenic potential, respectively. Furthermore, in vivo studies demonstrated a 97.16 ± 1.55% wound closure for Cs/PVP/1PRF group after 14 days.

Innovative Concepts and Recent Breakthrough for Engineered Graft and Constructs for Bone Regeneration: A Literature Systematic Review

BACKGROUND

For decades, regenerative medicine and dentistry have been improved with new therapies and innovative clinical protocols. The aim of the present investigation was to evaluate through a critical review the recent innovations in the field of bone regeneration with a focus on the healing potentials and clinical protocols of bone substitutes combined with engineered constructs, growth factors and photobiomodulation applications.

METHODS

A Boolean systematic search was conducted by PubMed/Medline, PubMed/Central, Web of Science and Google scholar databases according to the PRISMA guidelines.

RESULTS

After the initial screening, a total of 304 papers were considered eligible for the qualitative synthesis. The articles included were categorized according to the main topics: alloplastic bone substitutes, autologous teeth derived substitutes, xenografts, platelet-derived concentrates, laser therapy, microbiota and bone metabolism and mesenchymal cells construct.

CONCLUSIONS

The effectiveness of the present investigation showed that the use of biocompatible and bio-resorbable bone substitutes are related to the high-predictability of the bone regeneration protocols, while the oral microbiota and systemic health of the patient produce a clinical advantage for the long-term success of the regeneration procedures and implant-supported restorations. The use of growth factors is able to reduce the co-morbidity of the regenerative procedure ameliorating the post-operative healing phase. The LLLT is an adjuvant protocol to improve the soft and hard tissues response for bone regeneration treatment protocols.

Regenerative Endodontic Procedures for the Treatment of Necrotic Mature Teeth: A Preliminary Randomised Clinical Trial

AIM

This preliminary randomised, prospective, controlled trial aimed to compare the clinical and radiographic outcomes of two regenerative endodontic procedures (REPs), revitalisation and a platelet-rich fibrin (PRF)-based technique, in the treatment of mature permanent teeth with necrotic pulps.

METHODOLOGY

The trial has been reported according to the Preferred Reporting Items for Randomised Trials in Endodontics 2020 guidelines. The study protocol was registered at the clinical trial registry (ClinicalTrials.gov) with identifier number NCT04158232. Twenty patients with mature necrotic anterior teeth with large periapical lesions were randomly allocated into two groups (n=10): group I, treated with revitalisation with the blood clot (BC) technique, and Group II, treated with a PRF-based technique. The follow-up was for 12 months. Periradicular healing was assessed using standardised radiographs taken at baseline, and at 6 and 12 months after treatment. An electric pulp tester was used to assess whether pulp sensibility had been regained during the follow-up period. Statistical analysis was conducted using Mann-Whitney test and Wilcoxon test for non-parametric data. For parametric data, repeated measures analysis of variance was used. The significance level was set at P≤0.05.

RESULTS

There was a significant increase in periradicular healing in both groups at 6 and 12 months, compared to that at baseline, with no significant difference between the studied groups after 12 months (P=0.143). There was a significant difference between the tooth sensibility readings at baseline, 6-month, and 12-month follow-up timepoints (P<0.001).

CONCLUSIONS

The findings of this preliminary trial indicate the potential for using REPs, such as revitalisation or PRF-based techniques, as treatment options for mature teeth with necrotic pulps. A higher level of evidence obtained through adequately powered clinical trials and longer follow-up periods are required to conclusively validate the different outcomes of REPs.

Comparative evaluation of implant stability with and without autologous platelet-rich fibrin prior to prosthetic loading - A split-mouth randomized clinical trial

Context:

Status of bone–implant interface or osseointegration can be assessed by using resonance frequency analysis (RFA), which measures implant stability. A modified implant surface can significantly enhance osseointegration and reduce healing period. Platelet-rich fibrin (PRF) consists of fibrin mesh with entrapped platelets and leukocytes that release a huge number of growth factors which contribute to wound healing and tissue regeneration.

Aims:

The present study aims to evaluate the effect of PRF on osseointegration in terms of implant stability.

Settings and Design:

This was a split-mouth randomized clinical trial.

Materials and Methods:

Sixty surgical sites were divided randomly into two groups. In Group 1 (thirty sites), PRF was placed in osteotomy sites before implant placement whereas no PRF was placed in Group 2 (thirty sites). Stability was measured using RFA in terms of implant stability quotient (ISQ) at baseline, 1 week, 1 month, and 3 months.

Statistical Analysis:

Intergroup comparison was done using Mann–Whitney U-test. Intragroup comparison was done using Friedman's test followed by pairwise comparison using Wilcoxon signed-rank test.

Results:

On intergroup comparison, Group 1 showed higher values for ISQ which were statistically significant (P < 0.05) at 1 week and 1 month. No significant difference (P > 0.05) was found at baseline and 3 months. Intragroup comparison and further pairwise comparison revealed a highly significant difference for values between all pairs of time intervals (P < 0.01) with higher values at 3 months.

Conclusions:

PRF has a significant effect on osseointegration of dental implants during the early healing period prior to loading.

The Effect of Calcium Gluconate on Platelet Rich Plasma Activation for VEGF-A Expression of Human Dental Pulp Stem Cells

Objective  Platelet-rich plasma (PRP) activation is an important factor in triggering the initial release of blood-derived growth factors from platelets. Vascular endothelial growth factor-A (VEGF-A) can be expressed by human dental pulp stem cells (hDPSCs) and plays an important role in dental pulp angiogenesis. The aim of this study is to analyze the effects of calcium gluconate on PRP activation in hDPSC VEGF-A expression.

Materials and Methods  Two types of PRP and their corresponding activators were analyzed in this study: PRP (activated using calcium chloride/CaCl ₂ ) and PRP-T (activated using CaCl ₂ with the addition of 10% calcium gluconate). hDPSCs were obtained by using an out-growth method (DPSCs-OG), and harvest between the fifth and sixth passages, then cultured in three different media groups: control, PRP, and PRP-T, which were planted in 96 wells (5 × 10 ³ each well). The VEGF-A expression of hDPSCs was analyzed by using an ELISA test and observed at 24, 48, and 72 hours.

Statistical Analysis  This study was performed by using one-way ANOVA ( p  < 0.05) test.

Results  There were significant differences between all groups ( p  < 0.05) at 48 and 72 hours of observations, and no significant differences in the PRP and PRP-T groups at 48 and 72 hours of observations ( p  > 0.05).

Conclusion  PRP and PRP-T were equally effective in inducing VEGF-A expression of hDPSCs.

Injectable platelet rich fibrin facilitates hair follicle regeneration by promoting human dermal papilla cell proliferation, migration, and trichogenic inductivity

Hair follicle regeneration has been successful in mice but failed in human being for years. Dermal papilla cells, a specialized mesenchymal stem cell derived from dermal papilla within hair follicles, is considered the key cells for hair follicle regeneration function as both regeneration initiator and regulator. Injectable platelet rich fibrin (i-PRF), a novel biomaterial rich in a variety of growth factors and three-dimensional scaffolds, has shown promising effects on tissue regeneration. In this study, we aimed to evaluate the application of i-PRF in human hair follicle regeneration by examining the biological effects of i-PRF on human dermal papilla cells (hDPCs). Biomaterial compatibility, cell viability, proliferation, migration, alkaline phosphatase activity and trichogenic inductivity were assessed after exposing hDPCs to different concentrations of i-PRF extracts. In addition, we investigated the ultrastructure of i-PRF with all cell components filtered. The results revealed that i-PRF possessing excellent biocompatibility and could significantly promote hDPCs proliferation, migration, and trichogenic inductivity. Furthermore, the concentration of i-PRF is able to remarkably influence hDPCs behavior in a dose-dependent pattern. Different concentrations exhibited differential effects on hDPCs behavior. In general, lower concentration promotes cell proliferation better than higher concentration, while higher concentration promotes cell function better reversely. Best concentration for hDPCs in vitro expending is 1% concentration. 20% concentration is optimal for hair follicle regeneration. In summary, our findings concluded that i-PRF facilitates hair follicle regeneration by promoting human dermal papilla cell proliferation, migration, and trichogenic inductivity.

Lyophilised Platelet-Rich Fibrin: Physical and Biological Characterisation

Background: Platelet-rich fibrin (PRF) has gained popularity in craniofacial surgery, as it provides an excellent reservoir of autologous growth factors (GFs) that are essential for bone regeneration. However, the low elastic modulus, short-term clinical application, poor storage potential and limitations in emergency therapy use restrict its more widespread clinical application. This study fabricates lyophilised PRF (Ly-PRF), evaluates its physical and biological properties, and explores its application for craniofacial tissue engineering purposes. Material and methods: A lyophilisation method was applied, and the outcome was evaluated and compared with traditionally prepared PRF. We investigated how lyophilisation affected PRF’s physical characteristics and biological properties by determining: (1) the physical and morphological architecture of Ly-PRF using SEM, and (2) the kinetic release of PDGF-AB using ELISA. Results: Ly-PRF exhibited a dense and homogeneous interconnected 3D fibrin network. Moreover, clusters of morphologically consistent cells of platelets and leukocytes were apparent within Ly-PRF, along with evidence of PDGF-AB release in accordance with previously reports. Conclusions: The protocol established in this study for Ly-PRF preparation demonstrated versatility, and provides a biomaterial with growth factor release for potential use as a craniofacial bioscaffold.

Effects of platelet concentrates on implant stability and marginal bone loss: a systematic review and meta-analysis

Background

Osseointegration is essential for the success and stability of implants. Platelet concentrates were reported to enhance osseointegration and improve implant stability. The purpose of this review is to systematically analyze the effects of platelet concentrates on implant stability and marginal bone loss.

Methods

Two researchers independently performed searches in the following databases (last searched on 21 July 2021): MEDLINE (PubMed), Cochrane Library, EMBASE, and Web of Science. In addition, a manual search was carried out on references of relevant reviews and initially included studies. All randomized controlled trials (RCTs) and controlled clinical trials (CCTs) on the application of platelet concentrates in the implant surgery procedure were included. The risk of bias of RCTs and CCTs were assessed with a revised Cochrane risk of bias tool for randomized trials (RoB 2.0) and the risk of bias in non-randomized studies—of interventions (ROBINS-I) tool, respectively. Meta-analyses on implant stability and marginal bone loss were conducted. Researchers used mean difference or standardized mean difference as the effect size and calculated the 95% confidence interval. In addition, subgroup analysis was performed based on the following factors: type of platelet concentrates, method of application, and study design.

Results

Fourteen studies with 284 participants and 588 implants were included in the final analysis. 11 studies reported implant stability and 5 studies reported marginal bone level or marginal bone loss. 3 studies had high risk of bias. The meta-analysis results showed that platelet concentrates can significantly increase implant stability at 1 week (6 studies, 302 implants, MD 4.26, 95% CI 2.03–6.49, P < 0.001) and 4 weeks (8 studies, 373 implants, MD 0.67, 95% CI 0.46–0.88, P < 0.001) after insertion, significantly reduced marginal bone loss at 3 months after insertion (4 studies, 95 implants, mesial: MD − 0.33, 95% CI − 0.46 to − 0.20, P < 0.001; distal: MD − 0.38, 95% CI − 0.54 to − 0.22, P < 0.001). However, the improvement of implant stability at 12 weeks after insertion was limited (P = 0.10). Subgroup analysis showed that PRP did not significantly improve implant stability at 1 week and 4 weeks after insertion (P = 0.38, P = 0.17). Platelet concentrates only placed in the implant sites did not significantly improve implant stability at 1 week after insertion (P = 0.20).

Conclusions

Platelet concentrates can significantly improve implant stability and reduce marginal bone loss in the short term. Large-scale studies with long follow‐up periods are required to explore their long-term effects and compare effects of different types.

Trial registration

This study was registered on PROSPERO, with the Registration Number being CRD42021270214.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01929-x.

From Blood to Regenerative Tissue: How Autologous Platelet-Rich Fibrin Can Be Combined with Other Materials to Ensure Controlled Drug and Growth Factor Release

The purpose of this review is to examine the latest literature on the use of autologous platelet-rich fibrin as a drug and growth factor carrier system in maxillofacial surgery. Autologous platelet-rich fibrin (PRF) is a unique system that combines properties such as biocompatibility and biodegradability, in addition to containing growth factors and peptides that provide tissue regeneration. This opens up new horizons for the use of all beneficial ingredients in the blood sample for biomedical purposes. By itself, PRF has an unstable effect on osteogenesis: therefore, advanced approaches, including the combination of PRF with materials or drugs, are of great interest in clinics. The main advantage of drug delivery systems is that by controlling drug release, high drug concentrations locally and fewer side effects within other tissue can be achieved. This is especially important in tissues with limited blood supply, such as bone tissue compared to soft tissue. The ability of PRF to degrade naturally is considered an advantage for its use as a "warehouse" of controlled drug release systems. We are focusing on this concentrate, as it is easy to use in manipulations and can be delivered directly to the surgical site. The target audience for this review are researchers and medical doctors who are involved in the development and research of PRFs further studies. Likewise, surgeons who use PRF in their work to treat patients and who advice patients to take the medicine orally.

In vitro Comparison of Adipogenic Differentiation in Human Adipose-Derived Stem Cells Cultured with Collagen Gel and Platelet-Rich Fibrin

Background: Adipose-derived stem cells (ADSCs) are the most preferred cell type, based on their phenotypic characteristics, plasticity, and favorable immunological properties for applications in soft-tissue augmentation. Hence, the present in vitro study was aimed to evaluate the adipogenic differentiation potential of human ADSCs upon culturing individually with collagen gel and platelet-rich fibrin (PRF).

Materials and methods: The collected lipoaspirate was used for establishing ADSCs using enzymatic digestion method. Then, the cells were analyzed for their morphology, viability, proliferation rate, population doubling time (PDT), colony-forming ability, cell surface markers expression, and osteogenic differentiation as biological properties. Further, ADSCs were evaluated for their adipogenicity using induction media alone, and by culturing with collagen gel and PRF individually for prospective tissue augmentation.

Results: ADSCs were successfully established in vitro and exhibited a fibroblast-like morphology throughout the culture period. Cells had higher viability, proliferation potential and showed their ability to form colonies. The positive expression of cell surface markers and osteogenic ability confirmed the potency of ADSCs. The ADSCs cultured on collagen gel and PRF, individually, showed higher number of differentiated adipocytes than ADSCs grown with adipogenic induction medium alone.

Conclusion: The extent of lipid accumulation by ADSCs was slightly higher when cultured on collagen gel than on PRF. Additional experiments are required to confirm better suitability of scaffold materials for soft-tissue regeneration.

Assessment of the Effect of A-PRF Application during the Surgical Extraction of Third Molars on Healing and the Concentration of C-Reactive Protein

Extraction procedures for mandibular third molars are performed all over the world every day. Local inflammation resulting from surgery, and the pain that patients experience, often make it impossible to take up daily life activities, such as work or sports. Growth and anti-inflammatory factors, located in the fibrin network, have a positive effect on tissue-healing processes and should also reduce local inflammation. Advanced platelet-rich fibrin (A-PRF) applied locally influences such processes as: angiogenesis, osteogenesis and collagenogenesis. It also affects mesenchymal cell lines and anti- and pro-inflammatory mediators. Due to the autologous origin of the material, their use in guide bone regeneration (GBR) is more and more widespread in dentistry. The results of previous studies indicate that the use of A-PRF in the treatment area significantly reduces postoperative pain, while the formation of edema is not affected. C-reactive protein (CRP), which is an acute phase protein, appears in the blood as a consequence of inflammation. Due to the dynamics of changes in concentration of CRP, it is a protein that is sufficiently sensitive and is used in studies to monitor the tissue healing process. The effect of A-PRF application on CRP concentrations, before and after surgery, has not been investigated yet. The study was conducted on 60 generally healthy patients. A faster decrease of CRP levels was shown in patients who used A-PRF after the procedure. Additionally, it accelerated healing and reduced the occurrence of a dry socket close to 0.

INTRABONY DEFECT TREATMENT WITH PLATELET-RICH FIBRIN, GUIDED TISSUE REGENERATION AND OPEN-FLAP DEBRIDEMENT: A RANDOMIZED CONTROLLED TRIAL

OBJECTIVE

To comparatively assess the outcomes of the treatment of periodontal intrabony defects with platelet-rich fibrin (PRF) combined with open-flap debridement (OFD), guided tissue regeneration (GTR) or OFD alone based on clinical, radiographic, and wound healing parameters for 12 months of follow-up.

MATERIALS AND METHODS

Ninety intrabony defects were randomly divided into 3 different groups and treated as group 1 (PRF + OFD), group 2 (GTR), or group 3 (OFD alone). Clinical parameters, including the plaque index, gingival index, bleeding on probing, probing depth (PD), clinical attachment loss (CAL), and tooth mobility were assessed at 3, 6, and 12 months. Additionally, the wound healing index was assessed at 7 and 14 days postsurgery. Radiographic parameters, including bony defect fill and alveolar crestal resorption, were measured at 6 and 12 months postsurgery and calculated using image analysis software.

RESULTS

Intragroup comparisons showed consistently significant improvements in all the clinical and radiographic parameters in the 3 groups at 12 months postsurgery. Compared to baseline, in group 1, the PD decreased to 2.37 ± 0.56; 3.30 ± 0.84; 4.80 ± 0.71 mm, and CAL decreased to 2.23 ± 0.90; 3.33 ± 0.71; 5.00 ± 0.46 mm; in group 2, the PD decreased to 2.30 ± 0.60; 3.23 ± 0.86; 4.63 ± 0.67 mm, and CAL decreased to 2.00 ± 0.98; 3.20 ± 0.71; 4.53 ± 0.57 mm); and in group 3, the PD decreased to 1.87 ± 0.68; 2.57 ± 1.36; 3.37 ± 1.00 mm, and CAL decreased to 1.60 ± 0.93; 2.23 ± 1.22; 3.37 ± 1.22 mm at 3, 6, and 12 months postsurgery, respectively. The bone fill percentages in group 1 (26.45 ± 16.47 and 45.25 ± 5.20%), group 2 (22.20 ± 15.76 and 42.15 ± 6.39%) and group 3 (10.21 ± 6.47 and 23.13 ± 6.98%) were observed at 6 and 12 months postsurgery. The alveolar crestal resorption levels were -1.07 ± 0.52 and -1.70 ± 0.60 mm in group 1, -1.03 ± 0.72 and -1.47 ± 0.73 mm in group 2 and 0.37 ± 0.62 and 0.43 ± 0.73 mm in group 3, respectively. The percentages of sites with a WHI score of 1 were 93% and 100% in group 1, 81%, and 94% in group 2 and 45% and 71% in group 3 at 7 and 14 days postsurgery, respectively.

CONCLUSIONS

Compared to GTR, PRF yielded comparable treatment outcomes and periodontal tissue healing in terms of improvements in clinical and radiographic parameters. Compared to OFD alone, PRF also significantly improved these parameters in the treatment of intrabony defects.

Platelet-Rich Plasma for Bone Fracture Treatment: A Systematic Review of Current Evidence in Preclinical and Clinical Studies

Background: Recently, there is an increasing interest in the therapeutic potential of platelet-rich plasma (PRP) for bone fracture treatment. Nevertheless, the effect of PRP for bone fracture treatment remains controversial and is still a matter of discussion. Therefore, we performed a systematic review to evaluate the efficacy and safety of PRP injection for treatment of bone fracture. Methods: The main bibliographic databases, including Medline, PubMed, Embase, Web of Science, and the Cochrane library, were comprehensively searched for studies focusing on the application of platelet-rich plasma (PRP) on bone fracture treatment. All relevant articles were screened for eligibility and subdivided into the preclinical and clinical studies. Data were extracted and presented systematically. Results: Finally, twenty-six in vitro preclinical studies (basic studies), nine in vivo preclinical studies (animal studies), and nine clinical studies, met the selection criteria, and were included in the present systematic review. Preclinical studies showed an overall positive effect of PRP on osteoblast-like cells in vitro and bone healing in animal models. The most used treatment for bone fracture in animal and clinical studies is fixation surgery combined with PRP injection. The clinical studies reported PRP shortened bony healing duration, and had no positive effect on improving the healing rate of closed fractures. However, the results of functional outcomes are controversial. Additionally, compared with control group, PRP would not increase the rate of postoperative wound infection. Conclusion: The present systematic review confirmed the continuing interests of PRP as an additional treatment for bone fracture. Preclinical studies highlighted the potential value of PRP as promising therapy for bone fracture. However, the preclinical evidence did not translate into a similar result in the clinical studies. In addition, types of fractures and procedures of PRP preparation are heterogeneous in enrolled studies, which might result in controversial results. Meanwhile, characteristics of PRP, such as platelet concentration, the numbers of leukocytes, still need to be determined and further research is required.

Apheresis Platelet Rich-Plasma for Regenerative Medicine: An In Vitro Study on Osteogenic Potential

Background: Platelet-Rich Plasma (PRP) induces bone regeneration; however, there is low evidence supporting its efficacy in bone healing. The lack of a standardized protocol of administration represents the main obstacle to its use in the clinical routine for bone defects’ treatment. The purpose of this study was to characterize PRP and elucidate its osteogenic potential. Methods: Platelet count, fibrinogen levels, and growth factors concentration were measured in PRP obtained by four apheresis procedures. HOB-01-C1, a pre-osteocytic cell line, was used to examine the effects of different PRP dilutions (from 1% to 50%) on cell viability, growth, and differentiation. Gene expression of RUNX2, PHEX, COL1A1, and OCN was also assayed. Results: PRP showed a mean 4.6-fold increase of platelets amount compared to whole blood. Among the 36 proteins evaluated, we found the highest concentrations for PDGF isoforms, EGF, TGF-β and VEGF-D. PDGF-AA positively correlated with platelet counts. In three of the four tested units, 25% PRP induced a growth rate comparable to the positive control (10% FBS); whereas, for all the tested units, 10% PRP treatment sustained differentiation. Conclusions: This study showed that PRP from apheresis stimulates proliferation and differentiation of pre-osteocyte cells through the release of growth factors from platelets.

Treatment of Refractory Medicine Related Osteonecrosis of Jaw With Piezosurgical Debridement and Autologous Platelet Rich Fibrin: Feasibility Study

ABSTRACT

Medicine related osteonecrosis of jaw (MRONJ) is incidental in patients receiving certain bone modifying agents in oncology. These lesions may not respond to conservative management and aggravate. Autologous platelet derivatives contain bone growth factors, which help in bone regeneration. The aim of this pilot study is to develop protocol for treatment of refractory MRONJ with pizosurgical debridement and advanced platelet rich fibrin.In this feasibility study, refractory MRONJ lesions were treated by piezosurgical debridement and insertion of autologous advanced platelet rich fibrin in 15 patients. One patient had 2 lesion sites, so in all 16 MRONJ sites were treated. These patients were evaluated at the end of 1 month and 4 months for healing of MRONJ lesion. Statistical analysis was done by using Fisher test for response assessment in relation to variable. Eight lesions (50%) showed complete healing at the end of 1 month. At the end of 4 months 13 lesions (81.50%) were completely healed, 2 lesions (12.5%) were downgrades, and 1 lesion (6.25%) did not respond to treatment. Number of doses of bone modifying agent was only factor found associated with nonhealing of MRONJ when treated with this protocol.In this pilot study, feasibility of use of piezosurgical debridement and platelet rich fibrin was evaluated. The results of the study suggest complete healing can be achieved with this treatment protocol. Further research with increased sample size is warranted to determine optimum use of autologous platelet concentrates in treatment of MRONJ.

Comparison Study of the Histomorphometric Results after Socket Preservation with PRF and Allograft Used for Socket Preservation-Randomized Controlled Trials

The aim of the present clinical study was to assess and compare the histomorphometric results and efficacy of freeze-dried bone allograft (FDBA) in combination with platelet-rich fibrin (PRF), and PRF as a sole grafting material for socket preservation. Ninety patients in need of tooth extraction and implant restoration were included in this study. The participants were randomly divided into three groups based on post-extraction clinical protocol: socket preservation procedure with allograft in combination with a PRF membrane (PRFm), PRF as a sole grafting material, and a control group. A total of 90 implants were placed four months post-extraction. During the surgical re-entry a bone biopsy was harvested with a trephine drill. Histological samples were prepared and analyzed for percentage vital bone and connective tissue. One-way ANOVA with Bonferroni post-hoc analysis were used to assess the results. Both test groups revealed a significantly higher percentage of vital bone formation compared to the control group. No statistically significant differences regarding vital bone formation and connective tissue quantity between the tested groups were observed (FDBA + PRFm: 3.29 ± 13.03%; and PRF: 60.79 ± 9.72%). From a clinical and histological point of view, both materials in the test groups are suitable for the filling of post-extraction sockets without bone defects. Both of the tested groups revealed a significantly higher percentage of vital bone formation compared to the control group.

Enhanced Bone Formation in Osteoporotic Mice by a Novel Transplant Combined with Adipose-derived Stem Cells and Platelet-rich Fibrin Releasates

Osteoporotic fracture is the main complication of osteoporosis (OP) and accounts for millions of injuries annually. Local intervention by intra-marrow injection has been a good option for preventing osteoporotic bone loss when the osteoporotic femoral fracture has been treated. In this study, tail vein transplantations were examined to evaluate the cell-based therapeutic approach for treating OP with adipose-derived stem cells (ADSCs) and platelet-rich fibrin releasates (PRFr) in an ovariectomized (OVX) mice model. Thirty-six 12-wk-old female ICR mice were randomly divided into six groups: untreated control; sham-operated; OVX-control; OVX-ADSCs; OVX-PRFr; and OVX-ADSCs+PRFr. Starting 8 wk after ovariectomy, the OVX mice received tail vein injections once each week for four consecutive weeks, then were evaluated radiographically and histopathologically 8 wk after the first injection. We also assessed changes to bone trabeculae in the proximal tibial growth plate. In OVX mice treated with ADSCs or PRFr alone, or with a combination of ADSCs and PRFr, the trabecular bone mineral density (BMD), bone volume ratios (BV/TV), and numbers (Tb.N) in the proximal tibia areas were significantly higher than that in the OVX-control group. Significant differences between OVX-treated mice and OVX controls were found for trabecular separation, but not for trabecular thickness. These results indicate that ADSCs or PRFr treatment enhances bone microarchitecture in OP. The treatment of bone loss of OVX mice with ADSCs+PRFr induced greater bone consolidation with bone tissue production (P < 0.01) when compared to the others. Thus, we conclude that the transplantation of ADSCs combined with PRFr might provide an alternative strategy for the treatment of various bone disorders in OP with an unlimited source of cells and releasates.

Long-Term Effects of Platelet-Rich Fibrin on Fat Graft Survival and Their Optimal Mixing Ratio

BACKGROUND

Platelet-rich fibrin (PRF) can promote fat graft survival, but the reported mixing ratio of PRF to fat ranges from 1:25 to 1:2, lacking a clear standard for clinical application.

OBJECTIVES

The authors sought to explore the long-term effects of PRF on grafted fat and their optimal mixing ratio.

METHODS

Nude mice were randomly divided into a control group (receiving subcutaneous injection of fat granules) and 4 PRF groups (receiving subcutaneous injection of PRF and fat granules at volume ratios of 1:5, 1:10, 1:15, and 1:20, respectively). The graft samples (n = 12) were obtained in weeks 4, 8, and 12 to (1) calculate retention rates; (2) evaluate gene and protein expression of vascular endothelial growth factor A (VEGF-A), peroxisome proliferator-activated receptor-γ (PPAR-γ), type I collagen A1 (COL1-A1), and B-cell lymphoma-2 associated X protein (BAX); (3) perform hematoxylin and eosin, Masson's trichrome, α-smooth muscle action, and periplipin-1 stainings; and (4) count the microvessels and viable adipocytes.

RESULTS

Compared with the control group, PRF groups had higher retention rates, a higher gene/protein expression of VEGF-A, a lower gene/protein expression of COL1-A1 and BAX, less fibrosis, and more microvessels and viable adipocytes. Group 1:10 was superior to other groups in terms of retention rates and other evaluation indexes. The expression of PPAR-γ did not significantly differ among groups.

CONCLUSIONS

PRF may not play a long-term effect on adipogenesis, but it can still promote fat graft survival through facilitating vascularization, regulating collagen production, and inhibiting apoptosis. PRF can achieve the best promoting effect when the mixing ratio of PRF to fat is 1:10, which is recommended as the optimal ratio for clinical application.

Assessment of the effects of local platelet-rich fibrin injection and piezocision on orthodontic tooth movement during canine distalization

INTRODUCTION

The study aimed to evaluate and compare the effects of local platelet-rich fibrin (PRF) injection and piezocision applications on tooth movement during canine distalization, as well as to evaluate any changes in the periodontal parameters.

METHODS

Twenty-four patients were randomly divided into 2 groups. A randomly selected side of the maxillary arch received either PRF injection (PRF group) or piezocision (piezocision group). The contralateral sides of both groups served as the controls. After piezocision and PRF injection applications, canine distalization was initiated in both groups with a 150 g force. Patients were followed every 2 weeks for a total 12 of weeks. The following variables were evaluated: cephalometric measurements, the amount of canine distalization, molar mesialization, canine rotation, transversal changes in dental models, and periodontal parameters.

RESULTS

The amount of canine distal movement was found to be greater in the experimental sides than in the control sides in both groups at 12 weeks (P <0.05). There were no differences in the amount of molar mesialization, canine rotation, or transversal measurements in both groups when compared with the experimental sides with the control sides (P >0.05). There were no differences in the skeletal measurements or periodontal parameters in both groups (P >0.05). In both groups, the maxillary incisors were retroclined and retracted.

CONCLUSIONS

PRF and piezocision accelerated tooth movement, but there were no differences between the 2 applications in terms of speed, amount, duration of tooth movement, or periodontal parameters during canine distalization.

Individualized plasticity autograft mimic with efficient bioactivity inducing osteogenesis

Mineralized tissue regeneration is an important and challenging part of the field of tissue engineering and regeneration. At present, autograft harvest procedures may cause secondary trauma to patients, while bone scaffold materials lack osteogenic activity, resulting in a limited application. Loaded with osteogenic induction growth factor can improve the osteoinductive performance of bone graft, but the explosive release of growth factor may also cause side effects. In this study, we innovatively used platelet-rich fibrin (PRF)-modified bone scaffolds (Bio-Oss^®) to replace autograft, and used cytokine (BMP-2) to enhance osteogenesis. Encouragingly, this mixture, which we named “Autograft Mimic (AGM)”, has multiple functions and advantages. (1) The fiber network provided by PRF binds the entire bone scaffold together, thereby shaping the bone grafts and maintaining the space of the defect area. (2) The sustained release of BMP-2 from bone graft promoted bone regeneration continuously. (3) AGM recruited bone marrow mesenchymal stem cells (BMSCs) and promote their proliferation, migration, and osteogenic differentiation. Thus, AGM developed in this study can improve osteogenesis, and provide new guidance for the development of clinical bone grafts.

Potential Bone Regenerative Effects of DFDBA, Simvastatin and Platelet Rich Fibrin, Radiographically and Histologically of Intra-Bony Periodontal Defects in White New Zealand Rabbits

AIM: This study aimed to evaluate and to compare the regenerative power of simvastatin, Demineralized Freeze-Dried Bone Allograft (DFDBA) allograft, platelets rich Fibrin (PRF), and a combination of these materials radiographically and histologically in the intra-bony periodontal defects in white New Zealand rabbits. MATERIALS AND METHODS: This study was conducted on 54 defects in 27 adult male rabbits (n = 27) which were divided into three groups according to the follow-up preplanned scheduled for 1, 2, and 3 weeks. The selected materials were induced as following: A=DFDBA, B=Simvastatin, C= PRF, D=A+C, E=B+C, and F=negative (control group). The intra-bony periodontal defects were induced as the form of one osseous wall defect of 10 mm height, 4 mm depth between the first and the second molars. Then, samples were prepared for histological evaluation. Radiographic assessment was done using computed tomography radiography which was carried at different time intervals as the following baseline, 1, 2, and 3 weeks later. Statistical analysis was performed using ANOVA. RESULTS: After evaluating the results, macroanatomy, radiographically, and histologically, it is thus confirmed that DFDBA allograft combined with PRF create the best bone regenerative results, followed by DFDBA, Simvastatin, simvastatin+ PRF, control group, and finally PRF. CONCLUSION: All of the materials examined in this study showed different percentage in terms of bone density and bone regenerative effects. However, the best results for bone density of the DFDBA + PRF group were recorded after 3 weeks. Thus, the study concludes that a combination of DFDBA + PRF reflects the best properties of both materials in terms of bone density results of the defect. Such results are particularly significant for the selection of bone regeneration materials, and generally, for periodontal regeneration.

Use of PRP, PRF and CGF in Periodontal Regeneration and Facial Rejuvenation-A Narrative Review

Growth factors (GFs) play a vital role in cell proliferation, migration, differentiation and angiogenesis. Autologous platelet concentrates (APCs) which contain high levels of GFs make them especially suitable for periodontal regeneration and facial rejuvenation. The main generations of APCs presented are platelet-rich plasma (PRP), platelet-rich fibrin (PRF) and concentrated growth factor (CGF) techniques. The purpose of this review is to provide the clinician with an overview of APCs' evolution over the past decade in order to give reliable and useful information to be used in clinical work. This review summarizes the most interesting and novel articles published between 1997 and 2020. Electronic and manual searches were conducted in the following databases: Pubmed, Scopus, Cochrane Library and Embase. The following keywords were used: growth factors, VEGF, TGF-b1, PRP, PRF, CGF and periodontal regeneration and/or facial rejuvenation. A total of 73 articles were finally included. The review then addresses the uses of the three different techniques in the two disciplines, as well as the advantages and limitations of each technique. Overall, PRP is mainly used in cases of hard and soft tissue procedures, while PRF is used in gingival recession and the treatment of furcation and intrabony defects; CGF is mainly used in bone regeneration.

Autologous Platelet-Rich Fibrin (PRF) as an Adjunct in the Management of Osteoradionecrosis and Medication-Related Osteonecrosis of Jaws. Case Series in A Single Centre

Osteoradionecrosis (ORN) of the jaws and medication-related osteonecrosis of the jaws (MRONJ) are uncommon but serious diseases affecting the oral and maxillofacial region with clinically similar appearance but distinct pathophysiology. Management of ORN and MRONJ is inherently challenging and the treatment outcomes are unpredictable. The use of autologous platelet concentrates (APCs) to promote hard and soft tissue healing is well described in the literature, and the efficacy of leucocyte and platelet-rich fibrin (L-PRF) has been well documented in a number of clinical studies. The aim of this study was to present our treatment strategy and the outcomes of incorporating L-PRF as a surgical adjunct in management of ORN and MRONJ in our centre. Methods: eight cases of ORN and MRONJ were treated with a combination of sequestrectomy and L-PRF as a surgical adjunct. Results: the overall success was 87.5%. Using L-PRF as an adjunct, we were able to predictably manage ORN and MRONJ without causing significant morbidity. Conclusion: our experience shows that L-PRF may be used as a valuable and cost-effective adjunct to surgical management of ORN and MRONJ. However, due to a limited number of patients, and a short period of review, the true effectiveness of the method is yet to be demonstrated in a longer follow-up study including a greater number of patients, besides the inclusion of a control group.

Platelet-rich fibrin: Basics of biological actions and protocol modifications

Platelet-rich fibrin (PRF) represents second generation of platelet concentrates, which has gained increasing awareness in recent years for regenerative procedures. This biologic additive is completely autologous, easy to prepare, has minimal expense, and possesses prolonged growth factor release, together with several other advantages over traditionally prepared platelet concentrates. Since its introduction, various protocols for PRF preparation have been proposed with different amounts of growth factors and other biomolecules necessary for wound healing. However, reference data about potential effect of some PRF components on hard and soft tissue healing are still conflicting. The current article intends to clarify the relevant advances about physiological role of certain PRF components and to provide insight into the new developmental approach. Also, this review summarizes the evolution of platelet concentrates and biologic properties of different modifications of PRF procedure.

Evaluation of platelet-rich fibrin and tricalcium phosphate bone graft in bone fill of intrabony defects using cone-beam computed tomography: A randomized clinical trial

BACKGROUND

Platelet-rich fibrin (PRF) is the second-generation platelet concentrate first described by Choukron et al. It incorporates leukocytes, platelets, and growth factors within dense fibrin matrix, can be used in periodontal regeneration alone or in combination with bone grafts.

AIM

This study assesses bone fill in intrabony defects, following the use of β tricalcium phosphate (TCP) bone graft with and without PRF.

MATERIALS AND METHODS

Thirty sites with intrabony defects in periodontitis patients were selected, randomly allotted into three groups: Group A open flap debridement (OFD), Group B OFD with β TCP with PRF, and Group C β TCP. Clinical parameters such as plaque index, gingival index, sulcus bleeding index, and PPD recorded at baseline and 6 months. Radiographic parameters include cementoenamel junction (CEJ) to base of defect, CEJ to alveolar crest, depth of defect, and bone fill assessed using the cone-beam computed tomography (CBCT). The comparison between the test group and control group in terms of clinical and radiographical parameters was assessed using the independent sample t-test.

RESULTS

Significant reduction in probing depth measurements, defect fill observed in both β TCP with PRF and β TCP alone groups compared to OFD. However, intergroup comparison assessed using the independent sample t-test found to be statistically nonsignificant (P < 0.05 is considered significant).

CONCLUSION

All three treatment strategies resulted in significant reduction in probing depth and bone fill at 6 months. Bone fill achieved in β TCP with PRF was more compared to β TCP alone and OFD at 6 months follow-up. CBCT can be accurately used to assess the morphology of intrabony defect and also in evaluating bone fill.

Complementarity of Photo-Biomodulation, Surgical Treatment, and Antibiotherapy for Medication-Related Osteonecrosis of the Jaws (MRONJ)

Background and Objectives: Antiresorptive or anti-angiogenic agents may induce medication-related osteonecrosis of the jaws (MRONJ), which represents a challenge for clinicians. The aim of this study is to design and apply a composed and stage-approach therapy combining antibiotherapy, surgical treatment, and photo-biomodulation (PBM) for the prevention or treatment of MRONJ lesions. Materials and Methods: The proposed treatment protocol was carried out in the Department of Oral & Maxillofacial Surgery of the “Victor Babes” University of Medicine and Farmacy of Timisoara, in 2018–2020. A total of 241 patients who were previously exposed to antiresorptive or anti-angiogenic therapy, as well as patients already diagnosed with MRONJ at different stages of the disease were treated. A preventive protocol was applied for patients in an “at risk” stage. Patients in more advanced stages received a complex treatment. Results: The healing proved to be complete, with spontaneous bone coverage in all the n = 84 cases placed in an “at risk” stage. For the n = 49 patients belonging to stage 0, pain reductions and decreases of mucosal inflammations were also obtained in all cases. For the n = 108 patients proposed for surgery (i.e., in stages 1, 2, or 3 of MRONJ), a total healing rate of 91.66% was obtained after the first surgery, while considering the downscaling to stage 1 as a treatment “success”, only one “failure” was reported. This brings the overall “success” rate to 96.68% for a complete healing, and to 99.59% when downscaling to stage 1 is included in the healing rate. Conclusions: Therefore, the clinical outcome of the present study indicates that patients with MRONJ in almost all stages of the disease can benefit from such a proposed association of methods, with superior clinical results compared to classical therapies.

Effect of injectable platelet-rich fibrin (i-PRF) in accelerating orthodontic tooth movement : A randomized split-mouth-controlled trial

BACKGROUND

The role of platelet-rich fibrin (PRF) in accelerating orthodontic tooth movement has been controversially discussed in available clinical studies.

OBJECTIVE

To investigate the effectiveness of i‑PRF in accelerating maxillary canine retraction.

MATERIALS AND METHODS

A split-mouth design was applied in 21 participants (6 men, 15 women; mean age: 20.85 ± 3.85 years) whose class II division I malocclusion required the extraction of both maxillary first premolars. The right and left canines were randomized into intervention and control sides. After the initial leveling and alignment phase and immediately before canine retraction, i‑PRF obtained from the brachial vein was injected into the mucosa on the buccal and palatal aspects of the intervention sides. The injection was repeated one month later. Study casts were taken at the initiation of canine retraction (T0) and at monthly visits up to 5 months (T1 through T5). The paired t‑test was used to compare the total and monthly rates of canine retraction, canine rotation, and anchorage loss.

RESULTS

The average rates of canine retraction were greater on the experimental side at T2, T3, and T4, but this difference with the control side was statistically significantly different only at T2 (P < 0.05). Differences in canine rotation and anchorage loss were not statistically significant.

CONCLUSION

The rates of canine retraction following the injection of platelet-rich fibrin were not statistically significantly greater on the experimental than the control sides except at the second month (T2). This apparently transient rate of tooth movement indicates that repeated injections might be needed for sustained effects, a premise meriting more focused research.

Effect of leukocyte and platelet rich fibrin (L-PRF) on stability of dental implants. A systematic review and meta-analysis

The aim of this study was to assess the impact, if any, of L-PRF application in an implant bed prior to implant placement, focusing on stability by means of implant stability quotient (ISQ) values. The literature was searched in a systematic way by means of the main databases and hand searching of the most relevant journals. The inclusion and exclusion criteria were used to determine the eligible studies included in this review. Only randomised controlled trials (RCT) and controlled clinical trials (CCT) were included. A total of four RCTs were included for data extraction. The risk of bias was deemed moderate to unclear. Meta-analysis was performed to assess the effect of L-PRF, on implant stability, immediately post-insertion in three studies, after one week from the implant placement in three studies and after four weeks for all the included studies. The fixed effects model has shown Hedges g statistic for the one week varying from 0.380 to 1.401 with a pooled figure of 0.764 (95% CI 0.443 to 1.085) and for four weeks varying between 0.74 and 1.1 with a combined effect of 0.888 (95% CI 0.598 to 1.177). The results for both intervals were in favour of the use of L-PRF while the statistical difference immediately post-insertion was not statistically significant. The present systematic review, though acknowledging its limitations, suggests that L-PRF has a positive effect on secondary implant stability and that needs to be correlated to the clinical practice to measure the actual clinical effect by means of reducing treatment times.

Does the application of GaAlAs laser and platelet-rich plasma induce cell proliferation and increase alkaline phosphatase activity in human dental pulp stem cells?

Blood extracts containing platelet products are gaining popularity in promoting healing and pulp regeneration. This study was designed to evaluate the effect of platelet-rich plasma (PRP) and gallium-aluminum-arsenide (GaAlAs) laser on proliferation and differentiation of human dental pulp stem cells (hDPSCs). In this ex vivo study, hDPSCs isolated from impacted mandibular third molars were cultured in Dulbecco's Modified Eagle's medium )DMEM(with 10% fetal bovine serum (FBS). After reaching the desired confluence, the cells were distributed into 4 groups, namely, control, PRP, laser, and PRP+laser for MTT assay and alkaline phosphatase (ALP) test. In the PRP and PRP+laser groups, 10% PRP was added to each well on the plate. In the laser and PRP+laser groups, as for the proliferation test, laser irradiation was carried out for 45 s, while 135 s was designated for ALP test. After 1, 3, and 5 days, cell proliferation and ALP activity were assessed using MTT and ALP colorimetric assay, respectively. Two-way ANOVA was utilized to analyze data. In PRP and PRP+laser groups, cell proliferation and viability increased until day 3 but began to decline afterwards until the 5th day. In the laser group, the increase in proliferation and viability was observed till day 5 which was less than the control group. Laser and control groups exhibited significantly higher cell viability and proliferation than both PRP and PRP+laser groups. ALP activity was more pronounced in PRP+laser, PRP, and laser in descending order; however, all were less than that of the control group. Only in the control group did the ALP activity augment during the 5-day period. Laser irradiation could induce pulp cell proliferation and demonstrated a better performance than PRP in this regard.

Mineralized Plasmatic Matrix for Horizontal Ridge Augmentation in Anterior Maxilla with and without a Covering Collagen Membrane

Background:

Mineralized Plasmatic Matrix [MPM] is a unique form of platelet rich fibrin that contains mineralized bone graft particles within a fibrin network.

Aim:

This study was conducted to evaluate horizontal ridge augmentation using MPM with and without a coverage membrane.

Materials and Methods:

Sixteen edentulous spaces were randomly divided into 2 equal groups. MPM was used for horizontal ridge augmentation with and without a covering collagen membrane (group 1 and 2, respectively). Cone Beam CT images were obtained preoperatively as well as 1 week and 4 months postoperatively to evaluate alveolar ridge and the resorption of the grafting material at 3 predetermined points along with the site where the future dental implant will be placed.

Student’s t-test (Unpaired) was used for comparing two different groups with quantitative parametric data and student’s t-test (Paired) was used for comparing two related groups with quantitative parametric data while repeated measures ANOVA (Analysis of variance) followed by post-hoc Bonferroni was used for comparing more than two related groups with quantitative parametric data.

Student’s t-test (Unpaired) was used for comparing two different groups with quantitative parametric data and student’s t-test (Paired) was used for comparing two related groups with quantitative parametric data while repeated measures ANOVA (Analysis of variance) followed by post-hoc Bonferroni was used for comparing more than two related groups with quantitative parametric data.

Results:

There was no statistically significant difference between the gained bone width in both groups. More but not statistically significant resorption was recorded in group 2.

Conclusion:

MPM can be successfully used for horizontal ridge augmentation without a barrier membrane.