Advanced platelet-rich fibrin (A-PRF) has an impact on the initial healing of gingival regeneration after tooth extraction

Application of Advanced Platelet-Rich Fibrin in Oral and Maxillo-Facial Surgery: A Systematic Review

Background: Advanced platelet-rich fibrin (A-PRF) is produced by centrifuging the patient's blood in vacuum tubes for 14 min at 1500 rpm. The most important component of A-PRF is the platelets, which release growth factors from their ⍺-granules during the clotting process. This process is believed to be the main source of growth factors. The aim of this paper was to systematically review the literature and to summarize the role of A-PRF in oral and maxillo-facial surgery. Materials and Methods: A systematic review was carried out, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO: CRD42024584161). Results: Thirty-eight articles published before 11 November 2024 were included in the systematic review. The largest study group consisted of 102 patients, and the smallest study group consisted of 10 patients. A-PRF was most often analyzed compared to leukocyte-PRF (L-PRF) or blood cloth. A-PRF was correlated with lower postoperative pain. Also, A-PRF was highlighted to have a positive effect on grafting material integration. A-PRF protected areas after free gingival graft very well, promoted more efficient epithelialization of donor sites and enhanced wound healing. Conclusions: Due to its biological properties, A-PRF could be considered a reliable addition to the surgical protocols, both alone and as an additive to bio-materials, with the advantages of healing improvement, pain relief, soft tissue management and bone preservation, as well as graft integration. However, to determine the long-term clinical implications and recommendations for clinical practice, more well-designed randomized clinical trials are needed in each application, especially those with larger patient cohorts, as well as additional blinding of personnel and long follow-up periods.

Assessing the effectiveness of advanced platelet rich fibrin in treating gingival recession: a systematic review and meta-analysis

OBJECTIVES

The literature lacks comprehensive evidence on the efficacy of advanced platelet rich fibrin(A-PRF) in treating gingival recession. Therefore, this systematic review and meta-analysis aimed to evaluate the effectiveness of A-PRF in the treatment of gingival recession.

MATERIALS AND METHODS

We adhered to the guidelines of PRISMA in searching the following databases: PubMed/MEDLINE, Embase, Cochrane Library, Web of Science, and Scopus to include all the eligible studies according to the prespecified inclusion and exclusion criteria. We conducted our search up to February 28, 2024. We conducted a meta-analysis of the primary and secondary clinical outcomes to measure the changes from baseline to 6 months after surgery.

RESULTS

Our review included 10 randomized clinical trials in which 146 participants with 457 recession defects were included. We found that combination of A-PRF with various surgical techniques, such as coronally advanced flap (CAF) connective tissue graft (CTG), VISTA, tunneling, and pinhole surgical technique, demonstrated promising outcomes but varied by comparison group. We observed that CTG with CAF showed a higher reduction in recession depth in comparison to A-PRF with CAF. This review indicated no statistical or clinical differences in recession width, width of keratinized gingiva, probing depth, and clinical attachment level between the study and control groups.

CONCLUSIONS

Due to the less invasive nature of A-PRF, it provides a better clinical option to improve the outcomes of treating gingival recession. However, more well-designed RCTs with standardized approaches are needed to confirm these results.

Influence of haematological parameters on size of the advanced platelet-rich fibrin+ (A-PRF+) in the horse

The advanced-PRF+ (A-PRF+) is a platelet concentrate, showing a higher concentration of growth factors, an increased number of cells and looser structure of the fibrin clot than leukocyte-PRF. A high variability in the size of PRF associated with patients, haematological features and centrifugation protocols was reported. The aims of this study were to evaluate the feasibility of A-PRF+ production in the field and the correlation between haematological parameters, macroscopic and microscopic features in equine A-PRF+. Samples from twenty Standardbred horses (3-7 years) were harvested with glass tubes without anticoagulants, previously heated at 37 °C. Blood samples were centrifugated at 1300 rpm for 8 min with a fixed-angle centrifuge and a horizontal centrifuge in the field, at a temperature of 15-17 °C. Clots were measured and placed on the Wound Box® for a 2-min compression. Membranes were measured and fixed in 10% formalin for histological examination. Clot and membrane surface did not differ between sex and centrifuge. Haematological parameters did not show a significant correlation to clot and membrane size. Membranes obtained from both centrifugation protocols showed a loose fibrin structure and cells evenly distributed throughout the clot. Tubes' warming was effective to obtain A-PRF+ clots from all samples, regardless the environmental temperature. Further studies are needed to evaluate the influence of other blood molecules on the A-PRF+ structure and size.

Ultrasonographic analysis of palatal donor site healing accelerated with platelet-rich fibrin following subepithelial connective tissue harvesting

OBJECTIVE

Platelet-rich fibrin (PRF) contains a variety of growth factors and bioactive molecules that play crucial roles in wound healing and angiogenesis. We aimed to evaluate the effects of PRF on tissue thickness and vascularization of the palatal donor site by ultrasound (USG) following subepithelial connective tissue harvesting.

METHODOLOGY

A subepithelial connective tissue graft was harvested from the palatal region with a single incision for root coverage in 20 systemically healthy patients. In the test group (n = 10), the PRF membrane was placed at the donor site, whereas no material was applied in the control group (n=10). Palatal tissue thickness (PTT) and pulsatility index (PI) were evaluated by USG at baseline and on the 3rd, 7th, 14th, 30th, and 90th days after surgery. The early healing index (EHI) was used to evaluate donor site healing for 30 days.

RESULTS

PTT was significantly higher in the PRF group on the 3rd and 14th days after surgery when compared to the controls. In the PRF-treated group, PI levels were significantly higher than in the controls, especially on the 14th day. PTT increased significantly 90 days after surgery compared to the test group baseline, but controls showed a significant decrease. The PRF group showed statistically significant improvements in EHI scores compared to controls on days 3, 7, and 14. This study found a negative correlation between PI values and EHI scores on postoperative days three and seven in the test group.

CONCLUSION

USG is a non-invasive, objective method to radiographically evaluate the regenerative effects of PRF on palatal wound healing after soft tissue harvesting. To overcome graft inadequacy in reharvesting procedures, PRF application may enhance clinical success and reduce possible complications by increasing tissue thickness and revascularization in the donor area.

Evaluation of the effects of platelet-rich fibrin and diode laser on gingival blood perfusion and early bone healing of the extraction socket: a randomized controlled clinical trial

Evaluation and comparison of the effect of platelet-rich fibrin (PRF), diode laser, and combination of PRF and diode laser on gingival blood perfusion and early bone formation of the extraction socket. Forty maxillary premolar sockets were randomized to four groups: control group, PRF group, diode laser group, and PRF + diode laser group. Gingival blood perfusion was measured at preoperative and postoperative 1, 3, 7, and 30 days. Fractal dimension analysis was performed immediately after the procedure and in the postoperative first month. Gingival perfusions significantly increased during 1 week compared to baseline for all groups with a mean of -4.43 ± 3.20, -5.99 ± 3.68, -5.45 ± 3.01, and -4.78 ± 2.82 respectively, and were at baseline 1 month later. There were no statistically significant differences between the groups at any time point. Although the increase of fractal dimension was higher in the PRF or diode laser group than in the control group with a mean of 0.085 ± 0.05, 0.100 ± 0.04, and 0.072 ± 0.04 respectively, no statistically significant differences were detected. Fractal dimension was significantly greater in PRF + diode laser group than in the control group with a mean of 0.138 ± 0.05 (p = 0.04). PRF, diode laser, and PRF + diode laser did not significantly affect the gingival perfusion, and the combined application of PRF and diode laser had positive effects on early bone regeneration in the extraction socket. PRF, diode laser, and PRF + diode laser provide better tissue healing of the extraction socket.

Evaluation of perfusion parameters of gingival inflammation using laser Doppler flowmetry and tissue spectrophotometry- a prospective comparative clinical study

BACKGROUND

The aim of this study was to determine the values of different perfusion parameters- such as oxygen saturation, the relative amount of hemoglobin, and blood flow- in healthy subjects compared to patients with gingivitis as a non-invasive measurement method.

METHODS

A total of 114 subjects were enrolled in this study and separated into subjects with gingivitis (50) and without gingivitis (64) based on clinical examination. Gingival perfusion was measured at 22 points in the maxilla and mandible using laser Doppler flowmetry and tissue spectrophotometry (LDF-TS) with the "oxygen to see" device. All patients underwent measurement of gingival perfusion, followed by the clinical evaluation (measurement of probing depths, evaluation of bleeding on probing, plaque level, and biotype). Perfusion parameters were compared between the groups, associations between the non-invasive and clinical measurements were analyzed, and theoretical optimal cut-off values for predicting gingivitis were calculated with receiver operating characteristics.

RESULTS

The mean oxygen saturation, mean relative amount of hemoglobin, and mean blood flow all significantly differed between the groups with and without gingivitis (p = 0.005, p < 0.001, and p < 0.001, respectively). The cut-off value for predicting gingivitis was > 40 AU (p < 0.001; sensitivity 0.90, specificity 0.67).

CONCLUSIONS

As a non-invasive method, LDF-TS can help determine gingival hyperemia. Flow values above 40 AU indicate a higher risk of hyperemia, which can be associated with inflammation. The LDF-TS method can be used for the objective evaluation of perfusion parameters during routine examinations and can signal the progression of hyperperfusion before any change in clinical parameters is observed.

TRIAL REGISTRATION

All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by the institutional Clinical Research Ethics Committee (Ethik-Kommission der Medizinischen Fakultät der RWTH Aachen, Decision Number 286/20) and retrospectively registered by the German Clinical Trials Register (File Number DRKS00024048, registered on the 15th of October 2021).

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.

Regeneration processes of alveolar bone and microvascular changes after the application of platelet-rich fibrin

OBJECTIVES

Platelet-rich fibrin (PRF) is a promising agent for bone regeneration (BR). Platelets contain several growth factors that promote angiogenesis and BR. In this study, we observed the morphology of alveolar BR.

METHODS

PRF (Advanced PRF: A-PRF) was prepared by extracting 10 mL of blood from each dog in a collection tube before tooth extraction. The samples were centrifuged at 200 × g for 8 min and incubated for 10 min to allow clotting. The alveolar socket on the dentition's right side was densely filled with PRF. The opposite side, which did not receive PRF, served as the control group. Different methods were used for specimen preparation and observation. Sections stained with hematoxylin and eosin were observed under a light microscope. Bone specimens were observed using stereoscopic microscopy. The resin cast models were examined using a scanning electron microscope. Moreover, bone formation ratio and height were measured.

RESULTS

Fourteen days postoperatively, angiogenesis and bone deposition were more advanced in the PRF group than in the control group. Thirty days postoperatively, both groups developed porous bone. In the PRF group, new bone trabeculae (BT) and a network of blood vessels were formed in the bone marrow. Ninety days postoperatively, the resin cast showed a normal bone structure with BT and bone marrow. Thick BT were observed in the PRF group.

CONCLUSIONS

Growth factors in PRF stimulate microcirculation and promote angiogenesis and bone deposition. The benefits of PRF include safety and increased bone formation.

Third-Generation Platelet Concentrates in Periodontal Regeneration: Gaining Ground in the Field of Regeneration

Platelets are important for hemostasis and the healing of wounds. In clinical settings, healing cytokines including insulin-like growth factors (IGF), platelet-derived growth factors (PDGF), and transforming growth factors (TGF) are commonly implemented. The regenerative approach in dentistry frequently employs platelet concentrates (PCs) that are “autologous in origin” and have a high concentration of platelets, growth factors, and leukocytes. First-generation PCs is made of platelet-rich plasma (PRP), while second-generation PC is made of platelet-rich fibrin (PRF). Both have limitations, so modification protocols and development in PRP and PRF derivatives are required for advancement mechanisms, strength, biodegradability, retention ability in the field of regenerative dentistry, and so on. As third-generation PC, newer genera kinds of PRF, such as advanced-PRF (A-PRF), advanced-PRF+ (A-PRF+), injectable-PRF (i-PRF), and titanium-PRF (T-PRF), were introduced. A-PRF matrices in their solid form were introduced using the low-speed centrifugation concept (LSCC). The applied relative centrifugal force (RCF) for A-PRF is reduced to 208 g as a result of this improved preparation process. A-PRF features a greater number of neutrophil granules in the distal region, especially at the red blood cells-buffer coat (RBC-BC) interface, and the A-PRF clot has a more porosity-like structure with a bigger interfibrous space than PRF. Since the PRF is in a gel form and is difficult to inject, i-PRF was formulated to address this problem. Compared to the other two protocols, the i-PRF protocol requires far less time, and this is the advantage of this PC. This is because i-PRF just needs the blood components to be separated, which happens within the first two to four minutes. Compared to normal L-PRF, T-PRF creates fibrin that is thicker and more densely woven. Titanium has a higher hemocompatibility than glass, which could lead to greater polymerized fibrin formation. In periodontal regenerative operations, oral surgery, and implant dentistry, PRF and its newer advanced modifications have demonstrated promising results and desirable results in both soft and hard tissue regenerative techniques.

Biofunctionalization of Xenogeneic Collagen Membranes with Autologous Platelet Concentrate-Influence on Rehydration Protocol and Angiogenesis

Background: The aim of this study was to analyze possible interactions of different xenogeneic collagen membranes (CM) and platelet-rich fibrin (PRF). PH values were evaluated in the CM rehydration process with PRF, and their influence on angiogenesis was analyzed in vivo. Materials and Methods: Porcine (Bio-Gide®, Geistlich)- and bovine-derived collagen membranes (Symbios®, Dentsply Sirona) were biofunctionalized with PRF by plotting process. PRF in comparison to blood, saline and a puffer pH7 solution was analysed for pH-value changes in CM rehydration process in vitro. The yolk sac membrane (YSM) model was used to investigate pro-angiogenic effects of the combination of PRF and the respective CM in comparison to native pendant by vessel in-growth and branching points after 24, 48 and 72 h evaluated light-microscopically and by immunohistochemical staining (CD105, αSMA) in vivo. Results: Significantly higher pH values were found at all points in time in PRF alone and its combined variants with Bio-Gide® and Symbios® compared with pure native saline solution and pH 7 solution, as well as saline with Symbios® and Bio-Gide® (each p < 0.01). In the YSM, vessel number and branching points showed no significant differences at 24 and 48 h between all groups (each p > 0.05). For PRF alone, a significantly increased vessel number and branching points between 24 and 48 h (each p < 0.05) and between 24 and 72 h (each p < 0.05) was shown. After 72 h, CM in combination with PRF induced a statistically significant addition to vessels and branching points in comparison with native YSM (p < 0.01) but not vs. its native pendants (p > 0.05). Summary: PRF represents a promising alternative for CM rehydration to enhance CM vascularization.