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.

Management of Medication-Related Osteonecrosis of the Jaw (MRONJ) Using Leukocyte- and Platelet-Rich Fibrin (L-PRF) and Photobiomodulation: A Retrospective Study

Background. The aim of this study was to compare retrospectively the effect of three different treatment protocols on the healing outcome in patients with established medication-related osteonecrosis of the jaw (MRONJ). Methods. A total of 34 MRONJ patients were recruited from the Department database and were divided according to the treatment protocols in a study group (G1) and two control groups (G2 and G3). G1 was treated with antibiotic therapy, surgery, leukocyte- and platelet-rich fibrin (L-PRF), and photobiomodulation; G2 was treated with antibiotic therapy and surgery; G3 was treated with antibiotic therapy and photobiomodulation. Various clinical variables and treatment protocols were analyzed to determine their correlation with the healing outcome at three and six months of follow-up. Results. There was a significant association between the different treatment protocols and the outcomes at both three and six months follow-up (p = 0.001 and p = 0.002, respectively). No significant association was observed between the outcomes and MRONJ localization, MRONJ stage, duration of drug treatment, gender, diabetes, corticosteroid therapy, smoking habits, underlying disease, and history of chemotherapy at both three and six months follow-up. Conclusions. Our results show that the combination of antibiotic therapy, surgery, L-PRF, and photobiomodulation may effectively contribute to MRONJ management.

Autologous Platelet Concentrates in Treatment of Furcation Defects-A Systematic Review and Meta-Analysis

Background: The aim of this review was to evaluate the adjunctive effect of autologous platelet concentrates (APCs) for the treatment of furcation defects, in terms of scientific quality of the clinical trials and regeneration parameters assessment. Methods: A systematic search was carried out in the electronic databases MEDLINE, SCOPUS, CENTRAL (Cochrane Central Register of Controlled Trials), and EMBASE, together with hand searching of relevant journals. Two independent reviewers screened the articles yielded in the initial search and retrieved the full-text version of potentially eligible studies. Relevant data and outcomes were extracted from the included studies. Risk of bias assessment was also carried out. The outcome variables, relative to baseline and post-operative defect characteristics (probing pocket depth (PPD), horizontal and vertical clinical attachment loss (HCAL, VCAL), horizontal and vertical furcation depth (HFD, VFD) were considered for meta-analysis. Results: Ten randomized trials were included in this review. Only one study was judged at high risk of bias, while seven had a low risk, testifying to the good level of the evidence of this review. The meta-analysis showed a favorable effect regarding all outcome variables, for APCs used in adjunct to open flap debridement (p < 0.001). Regarding APCs in adjunct to bone grafting, a significant advantage was found only for HCAL (p < 0.001, mean difference 0.74, 95% CI 0.54, 0.94). The sub-group analysis showed that both platelet-rich fibrin and platelet-rich plasma in adjunct with open flap debridement, yielded significantly favorable results. No meta-analysis was performed for APCs in combination with guided tissue regeneration (GTR) as only one study was found. Conclusion: For the treatment of furcation defects APCs may be beneficial as an adjunct to open flap debridement alone and bone grafting, while limited evidence of an effect of APCs when used in combination with GTR was found.

Antimicrobial effect of platelet-rich fibrin: A systematic review of in vitro evidence-based studies

This systematic review (SR) aimed to evaluate the antimicrobial potential of different types of platelet-rich fibrin (PRF) often used in regenerative treatments. An electronic search was performed in four databases and in Gray literature for articles published until January, 2023. The eligibility criteria comprised in vitro studies that evaluated the antimicrobial effect of different types of PRF. For the analysis of the risk of bias within studies, the modified OHAT (Office of Health Assessment and Translation) tool was used. For the evaluation of the results, a qualitative critical analysis was carried out in the synthesis of the results of the primary studies. Sixteen studies published between 2013 and 2021 were included in this SR. The antimicrobial effects of PRF variations (PRF, injectable PRF [I-PRF], PRF with silver nanoparticles [agNP-PRF], and horizontal PRF [H-PRF]), were analyzed against 16 types of bacteria from the oral, periodontal, and endodontic environments. All types of PRF showed significant antimicrobial action, with the antibacterial efficacy being more expressive than the fungal one. The I-PRF, H-PRF, and agNP-PRF subtypes improve antimicrobial activity. According to the OHAT analysis, no study was classified as having a high risk of bias. Evidence suggests that PRF variations have significant antimicrobial activity, with bacterial action being greater than fungal. Evolutions such as I-PRF, H-PRF, and agNP-PRF improve antimicrobial activity. Future studies analyzing the clinical effect of these platelets are fundamental. This SR was registered in INPLASY under number INPLASY202340016.

Progress in Regenerative Medicine: Exploring Autologous Platelet Concentrates and Their Clinical Applications

The goal of regenerative medicine is to achieve tissue regeneration. In the past, commonly used techniques included autologous or allogeneic transplantation and stem cell therapy, which have limitations, such as a lack of donor sites in the case of autologous transplantation and the invasiveness of stem cell harvesting. In recent years, research has, therefore, focused on new and less invasive strategies to achieve tissue regeneration. A step forward in this direction has been made with the development of autologous platelet concentrates (APCs), which are derived from the patient's own blood. They can be classified into three generations: platelet-rich plasma (PRP), platelet-rich fibrin (PRF), and concentrated growth factors (CGFs). These APCs have different structural characteristics, depending on the distinctive preparation method, and contain platelets, leukocytes, and multiple growth factors, including those most involved in regenerative processes. The purpose of this review is to clarify the most used techniques in the field of regenerative medicine in recent years, comparing the different types of APCs and analyzing the preparation protocols, the composition of the growth factors, the level of characterization achieved, and their clinical applications to date.

The Effectiveness and Safety of Autologous Platelet Concentrates as Hemostatic Agents after Tooth Extraction in Patients on Anticoagulant Therapy: A Systematic Review of Randomized, Controlled Trials

One of the common challenges in oral surgery is dealing with patients who are taking oral anticoagulant/antiaggregant drugs. Several local hemostatic agents have been proposed as an alternative to conventional suturing. Among these, autologous platelet concentrates (APCs) have been widely used to decrease the risk of hemorrhage after dental extraction. Nevertheless, there is a lack of consensus regarding the superiority of any one specific hemostatic agent over the others. This systematic review is aimed at evaluating the effectiveness of APCs as hemostatic agents after tooth extraction in patients on anticoagulant therapy. A literature search was conducted of articles published before March 2023 on PubMed, Scopus, and the Cochrane Central Register of Controlled Trials (CENTRAL). Studies on the use of APCs in patients undergoing dental extractions and being treated with anticoagulant drugs were included. Only randomized, controlled trials (RCTs) published up to March 2023 were included; the outcomes assessed were the time to hemostasis, the presence of post-operative bleeding and pain, and the effectiveness of wound healing. The risk of bias for each RCT was assessed by using the 'risk of bias' tool (RoB 1.0). The research revealed 6 RCTs. The findings indicated that patients on anticoagulant therapy who received APCs without discontinuing their medication experienced a decreased post-operative bleeding, a shorter hemostasis time, reduced pain, and accelerated wound healing. However, due to the high/unclear risk of bias of the studies included, no definitive conclusions can be drawn on the superiority of APCs as hemostatic agents over other similar products. Additional studies are required to validate these findings.

Role of Biomaterials Used for Periodontal Tissue Regeneration-A Concise Evidence-Based Review

Periodontal infections are noncommunicable chronic inflammatory diseases of multifactorial origin that can induce destruction of both soft and hard tissues of the periodontium. The standard remedial modalities for periodontal regeneration include nonsurgical followed by surgical therapy with the adjunctive use of various biomaterials to achieve restoration of the lost tissues. Lately, there has been substantial development in the field of biomaterial, which includes the sole or combined use of osseous grafts, barrier membranes, growth factors and autogenic substitutes to achieve tissue and bone regeneration. Of these, bone replacement grafts have been widely explored for their osteogenic potential with varied outcomes. Osseous grafts are derived from either human, bovine or synthetic sources. Though the biologic response from autogenic biomaterials may be better, the use of bone replacement synthetic substitutes could be practical for clinical practice. This comprehensive review focuses initially on bone graft replacement substitutes, namely ceramic-based (calcium phosphate derivatives, bioactive glass) and autologous platelet concentrates, which assist in alveolar bone regeneration. Further literature compilations emphasize the innovations of biomaterials used as bone substitutes, barrier membranes and complex scaffold fabrication techniques that can mimic the histologically vital tissues required for the regeneration of periodontal apparatus.

Differences between first- and second-generation autologous platelet concentrates

Autologous platelet concentrates (APCs) applied alone or combined with other biomaterials are popular bioactive factors employed in regenerative medicine. The main biological rationale of using such products is to concentrate blood-derived growth factors and cells into the wound microenvironment to enhance the body's natural healing capacity. First-generation APC is represented by platelet-rich plasma (PRP). While different protocols have been documented for PRP preparation, they overall consist of two cycles of centrifugation and have important limitations related to the use of an anticoagulant first and an activator afterward, which may interfere with the natural healing process and the release of bioactive molecules. The second generation of platelet concentrates is represented by leukocyte and platelet-rich fibrin (L-PRF). L-PRF protocols involve a single centrifugation cycle and do not require the use of anticoagulants and activators, which makes the preparation more straight forward, less expensive, and eliminates potential risks associated with the use of activators. However, since no anticoagulant is employed, blood undergoes rapid clotting within the blood collection tube; hence, a timely management of L-PRF is crucial. This review provides an overview on the most documented protocols for APC preparations and critically discusses the main differences between first- and second-generation APCs in terms of cell content, protein release, and the formation of a 3D fibrin network. It appears evident that the inconsistency in reporting protocol parameters by most studies has contributed to conflicting conclusions regarding the efficacy of different APC formulations and has significantly limited the ability to interpret the results of individual clinical studies. In the future, the use of a standardized classification system, together with a detailed reporting on APC protocol parameters is warranted to make study outcomes comparable. This will also allow to clarify important aspects on the mechanism of action of APCs (like the role of leukocytes and centrifugation parameters) and to optimize the use of APCs in regenerative medicine.

Autologous Platelet Concentrates as Treatment for Avascular Necrosis of Femoral Head in a Dog

Avascular necrosis of the femoral head is a developmental disturbance that generally affects young dogs of small breeds and produces ischemic necrosis of the femoral head resulting in an incongruous and malformed joint. The most common treatment is the excisional arthroplasty of the head and femoral neck. The aim of this study is to describe the treatment of avascular necrosis in a Yorkshire dog using intra-articular injections of autologous platelet concentrate. Evaluations were made at 0, 15, 30, 60, and 120 days of treatment, describing the following parameters: clinical gait analysis, perimetry, goniometry, and radiographic evaluations. The results obtained in this case suggest that the autologous platelet concentrate may be an alternative for the treatment of avascular necrosis of the femoral head in dogs.

Impact of autologous platelet concentrates on wound area reduction: A meta-analysis of randomized controlled trials

This meta-analysis aimed to evaluate the impact of autologous platelet concentrates (APCs) on wound area reduction based on randomized controlled trials (RCTs). A comprehensive search was conducted in PubMed, Embase, China National Knowledge Infrastructure (CNKI), Web of Science, and the Cochrane Library to identify relevant literature. The primary outcome measure was the percentage of wound area reduction. Secondary outcome measures included wound healing time and the incidence of infection. A total of 14 studies were included in the meta-analysis. The results showed that the percentage of wound area reduction was significantly greater in the APCs group compared to conventional treatments (standardized mean difference [SMD] 1.98, 95% confidence interval [CI]: 1.27-2.68, p < 0.001). Subgroup analysis revealed that the percentage of wound area reduction varied based on wound location, follow-up duration, and type of APCs used. The healing time and incidence of infection presented no significant difference between the two groups. The findings suggest that APCs can effectively reduce wound areas when compared to conventional treatments, without increasing the risk of infection. In addition, the effectiveness of APCs in wound area reduction may vary depending on factors such as wound location, type of APCs used, and follow-up duration.

Do autologous platelet concentrates (APCs) have a role in intra-oral bone regeneration? A critical review of clinical guidelines on decision-making process

In the past decades, personalized regenerative medicine has gained increased attention. Autologous platelet concentrates (APCs) such as PRP, PRGF, and L-PRF, all serving as a source of a large variety of cells and growth factors that participate in hard and soft tissue healing and regeneration, could play a significant role in regenerative periodontal procedures. This narrative review evaluated the relative impact of APCs in alveolar ridge preservation, sinus floor augmentation, and the regeneration of bony craters around teeth, both as a single substitute or in combination with a xenograft. L-PRF has a significant beneficial effect on alveolar ridge preservation (bone quality). The data for PRGF are less convincing, and PRP is controversial. L-PRF can successfully be used as a single substitute during transcrestal (≥3.5 mm bone gain) as well as 1-stage lateral window sinus floor elevation (>5 mm bone gain). For PRGF and especially PRP the data are very scarce. In the treatment of bony craters around teeth, during open flap debridement, L-PRF as a single substitute showed significant adjunctive benefits (e.g., >PPD reduction, >CAL gain, >crater depth reduction). The data for PRP and PRGF were non-conclusive. Adding PRP or L-PRF to a xenograft during OFD resulted in additional improvements (>PPD reduction, >CAL gain, >bone fill), for PRGF no data were found. Autologous platelet concentrates demonstrated to enhance bone and soft tissue healing in periodontal regenerative procedures. The data for L-PRF were most convincing. L-PRF also has the advantage of a greater simplicity of production, and its 100% autologous character.

Computer-based quantification of an atraumatic sinus augmentation technique using CBCT

Our group recently developed an innovative maxillary sinus augmentation technique without the need of sinus membrane elevation, termed as "IPG" DET protocol. This technique utilizes autologous platelet concentrates (including platelet rich plasma (PRP), platelet rich fibrin (PRF), growth factors (GFs) and CD34+ stem cells), together with bone grafting materials positioned through intentionally perforated Schneider's membrane for flapless implant placement. This study aimed at evaluating the performance of "IPG" DET protocol in terms of new bone formation and implant stability at 8 months post-op. This prospective study consisted of forty-eight patients with a mean age of 52.8 years. A total of eighty-five implants were placed with "IPG" DET protocol in combination with autologous platelet concentrates. CBCT (cone beam computed tomography) was performed at two different time points: pre-operatively and at 8 months post-op. CBCT images were then compared by an intensity-based image algorithm to assess the newly formed bone in terms of gray scale values. Additionally, implant stability quotient (ISQ) was used to estimate implant osseointegration and success rate. The average new bone formation was 5.9 ± 0.9 mm2 per implant. All implants successfully osseointegrated, and ISQ ranged 62.3-71.7. According to the results of this study, "IPG" DET protocol in combination with autologous platelet concentrates is a successful technique for implant-supported rehabilitation of the edentulous posterior maxilla without the need of sinus floor elevation.

Essential principles for blood centrifugation

Currently, autologous platelet concentrates (APCs) are frequently used for soft- and hard-tissue regeneration, not only within the oral cavity, but also extra-orally including chronic wounds, burns, joints, dermatological conditions, among others. The benefits of APCs are largely influenced by the treatment strategy but also their preparation. This paper therefore discusses in detail: the physical properties of blood cells, the basic principles of blood centrifugation, the impact of the centrifugation protocol (rotations/revolutions per minute, g-force, variation between centrifuges), the importance of timing during the preparation of APCs, the impact of the inner surface of the blood tubes, the use/nonuse of anticoagulants within APC tubes, the impact of the patient's hematocrit, age, and gender, as well as the important requirements for an optimal centrifugation protocol. All these variables indeed have a significant impact on the clinical outcome of APCs.

Instructions for the use of L-PRF in different clinical indications

Autologous platelet concentrates (APCs) have demonstrated clear benefits across various clinical applications, including alveolar ridge preservation, guided tissue regeneration, guided bone regeneration, sinus floor elevation (both lateral window approach and transcrestal technique), endodontic surgery, the treatment of medication-related osteonecrosis of the jaw bones, and periodontal plastic surgery. To ensure an optimal clinical outcome, clinicians must adhere strictly to the protocol to prepare the APCs and, especially follow evidence-based surgical guidelines, often simple but crucial, to minimize the likelihood of errors. The majority of clinical trials reported on second-generation APCs [the leukocyte- and platelet-rich fibrin (L-PRF) family, including its modifications (A-PRF, A-PRF+, CGF, T-PRF, H-PRF, etc.)]. These second-generation APCs offer additional benefits compared to the first-generation APCs, making them the preferred choice for the development of clinical recommendations. These recommendations have been formulated through a meticulous examination of the available clinical data and the clinical experience of the authors of this paper.

The Effectiveness of Autologous Platelet Concentrates in the Clinical and Radiographic Healing after Endodontic Surgery: A Systematic Review

Regenerative techniques are increasingly applied in endodontic surgery, but different materials may have varying impacts on soft and hard tissue healing. This systematic review aims to evaluate the effectiveness of autologous platelet concentrates (APCs) in clinical and radiographic healing after endodontic surgery. The data for this systematic review were processed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for improving the reporting of systematic reviews and meta-analyses. A literature search was conducted until October 2023 on PubMed, Scopus, and Cochrane Databases. Randomized controlled trials and controlled clinical trials addressing the use of APCs in patients who presented persistent periapical lesions and needed periapical surgery were included. Dual publications, narrative reviews, systematic reviews, case series, questionnaires, animal studies, case reports, letters to the editor, in vitro studies, and abstracts were excluded. In total, the search resulted in 14 papers. Clinical and radiographical findings were reported, showing that when APCs were used, patients exhibited less pain and swelling and a greater reduction of apical radiolucency after 12 months follow-up on average. However, the moderate/high risk of bias of included studies and their high heterogeneity, do not allow one to draw definitive conclusions on the effectiveness of APC after endodontic surgery.

Autologous platelet concentrates in alveolar ridge preservation: A systematic review with meta-analyses

In order to evaluate the therapeutic advantages of various autologous platelet concentrates (APC) as a single biomaterial during alveolar ridge preservation (ARP), a systematic review with meta-analyses was conducted. PubMed, EMBASE, Web of Science, and Scopus were screened for randomized controlled trials (RCTs) that were released prior to 2024. The selected papers compared an APC with either unassisted healing (blood clot) or another biomaterial during ARP (third molars were not included). The outcome parameters included alveolar bone dimension alterations, soft tissue healing, and post-op pain intensity. The search yielded 35 papers (33 studies), one applying platelet-rich plasma (PRP), six using plasma rich in growth factors (PRGF), and 28 using leukocyte- and platelet-rich fibrin (L-PRF). These studies showed a large heterogeneity (e.g., outcome parameters, timing, surgical approach, and inclusion criteria), which hindered drawing strong conclusions. In most studies, however, ARP with PRP, PRGF, and L-PRF alone produced faster soft tissue healing, less post-extraction pain, less alveolar ridge resorption, more socket bone fill, and a higher bone density when compared to unassisted (spontaneous) healing. The ultimate benefit appears to be significantly influenced by the surgical approach. Limited literature exists comparing APC with other biomaterials for ARP, resulting in inconclusive data. APC application for ARP is a promising strategy to improve soft and hard tissue healing and reduce post-extraction pain.

Histologic evaluation of edentulous alveolar ridge horizontal bone augmentations using a xenogeneic bone substitute and autologous platelet concentrates: a case series

OBJECTIVES

This case series aimed to assess the efficacy of a novel horizontal ridge augmentation modality using histology. Combinations of "sticky bone" and tenting screws without autologous bone were used as augmentative materials.

METHOD AND MATERIALS

Five individuals presenting healed, atrophic, partially edentulous sites that required horizontal bone augmentation before implant placement were enrolled. Patients underwent the same augmentation type and 5 months of postoperative reentry procedures. The first surgery served as implant site development, whereas the biopsy and corresponding implant placement were performed during reentry. The bone was qualitatively analyzed using histology and histomorphometry and quantitatively evaluated using CBCT.

RESULTS

Four individuals healed uneventfully. Early wound dehiscence occurred in one case. Histology showed favorable bone substitute incorporation into the newly formed bone and intimate contact between de novo bone and graft material in most cases. Histomorphometry revealed an average of 48 ± 28% newly formed bone, 19 ± 13% graft material, and 33 ± 26% soft tissue components. The CBCT-based mean alveolar ridge horizontal increase was 3.9 ± 0.6 mm at 5 months postoperatively.

CONCLUSIONS

The described augmentation method appears suitable for implant site development resulting in favorable bone quality according to histology. However, clinicians must accommodate 1 to 2 mm of resorption in augmentative material width at the buccal aspect.