Differences between first- and second-generation autologous platelet concentrates

A narrative review on the use of autologous platelet concentrates during alveolar bone augmentation: Horizontal (simultaneous/staged) & vertical (simultaneous/staged)

This review aimed to answer the general question of whether autologous platelet concentrates (APCs, an autologous blood-derivative) can improve the outcome of alveolar bone augmentation. Three clinical scenarios were assessed: horizontal/vertical bone augmentation in combination with implant placement (simultaneous approach), horizontal bone augmentation in a staged approach, and vertical bone augmentation in a staged approach. An electronic literature search strategy was conducted for each review from the outset to July 1st, 2023. The titles and abstracts (when available) of all identified studies were screened and imported into a database. If articles appeared to meet the inclusion criteria or their title and abstract had insufficient data, the full text was obtained to make the final decision. All studies that met the inclusion criteria underwent data extraction. Moreover, the references of the identified papers were screened for additional studies. After title and abstract screening and selection criteria application, 14 clinical studies were included for the qualitative analysis: seven for horizontal/vertical bone augmentation in a simultaneous approach, five for horizontal bone augmentation in a staged approach, and two for vertical bone augmentation in a staged approach. There is scarce literature regarding the added value of APCs in bone augmentation, and most studies had small sample sizes, a lack of standardized protocols, and different outcome variables, which makes comparisons between studies difficult. Out of the 14 studies, four were well-designed randomized clinical trials, where we could find better results for the APCs groups. Most studies, particularly comparative and well-designed studies, demonstrated beneficial and promising results of using APCs in alveolar bone augmentation. However, before high-level evidence-based conclusions can be drawn, more randomized clinical trials must compare the benefits of adding APCs to the gold-standard approach.

L-PRF in extra-oral wound care

Leukocyte- and platelet-rich fibrin (L-PRF), a by-product of centrifuged autologous whole blood, contains high concentrations of platelets, leukocytes, and fibrin (the latter spontaneously creating a strong 3-D network (a membrane)). L-PRF membranes possess several characteristics essential in wound healing, including a barrier function, an antibacterial and analgesic activity, and the release of growth factors enhancing tissue regeneration and neo-vasculogenesis. This review investigated the role of L-PRF in treating non-responding chronic wounds such as diabetic foot, venous leg ulcers, pressure ulcers, complex wounds, leprosy ulcers (Hansen's Disease), and other demanding wounds. Chronic wounds affect millions worldwide, negatively impacting their quality of life, productivity, and life expectancy while incurring high treatment costs for themselves and private and public health systems. L-PRF has demonstrated clear adjunctive advantages in treating chronic skin wounds, shortening the time to complete wound closure, and improving patient-reported outcome measures (including reducing pain and minimizing the need for analgesics). Also, in other demanding wounds, L-PRF facilitates healing. To help clinicians, this article also proposes recommendations for the use of L-PRF in the treatment of extra-oral wounds.

Autologous platelet concentrates after third molar extraction: A systematic review

Surgical removal of impacted mandibular third molars is often followed by postoperative sequelae like pain, swelling, trismus, etc. This systematic review explored the benefits of applying different autologous platelet concentrates (APCs) in the extraction socket of third molars. For this systematic review, PubMed, EMBASE, Web of Science, and Scopus have been utilized, initially yielding 544 papers. The search was narrowed to randomized controlled trials (RCTs, n = 59) published before 2024, all comparing the outcome of applying APCs in the extraction socket of surgically removed impacted mandibular third molars with unassisted healing (blood clot). Most RCTs primarily assessed the impact of APCs on postoperative sequelae. Some RCTs looked at soft- and hard-tissue healing. Eleven studies used PRP, three PRGF, and 45 L-PRF. A detailed analysis revealed a large heterogeneity between studies rendering a meta-analysis impossible. Moreover, the risk of bias was considered high. In the majority of RCTs, the application of an APC resulted in statistically significant reductions of postoperative sequelae (lower pain intensity, lower consumption of analgesics, less postoperative edema, and a lower incidence of trismus and alveolar osteitis), as well as a faster soft tissue healing, and qualitatively and quantitatively better bone healing. A minority of studies reported significant differences in periodontal parameters distally from the second molar.

Platelet-rich fibrin as a hemostatic agent in dental extractions in patients taking anticoagulants or antiplatelet medication: a systematic review

OBJECTIVES

The aim of this systematic review was to evaluate whether platelet-rich-fibrin (PRF) is effective in preventing postoperative bleeding after dental extractions in patients on anticoagulation or antiplatelet therapy compared to stitches alone and different hemostatic agents.

MATERIALS AND METHODS

This systematic review was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) (registration number CRD42024562289). Two authors independently performed searches in several databases, including PubMed, EMBASE, Cochrane Library, and SCOPUS.

RESULTS

In total, 789 studies were identified, of which 11 met the inclusion criteria after full-text screening. Four studies evaluated the efficiency of PRF in patients on antiplatelet therapy, and seven studies analyzed its hemostatic effect in patients on anticoagulants. All studies showed sufficient hemostasis when PRF was used, but due to heterogeneity meta-analysis was not possible.

CONCLUSIONS

Despite the use of different protocols and control groups, PRF treatment seems to be superior to only stitches and inferior to chitosan dressings concerning the time of hemostasis. Additionally, PRF seems to be beneficial in terms of faster wound healing and less postoperative pain.

CLINICAL RELEVANCE

PRF is known to enhance soft tissue healing and reduce postoperative pain. As a fully autologous platelet concentrate, it can support hemostasis after dental extractions in patients on antiplatelet or anticoagulation therapy. This systematic review aims to provide an update of the existing literature on PRF and its hemostatic capacity in patients with blood thinning medication.

Leukocyte-and Platelet-Rich Fibrin for enhanced tissue repair: an in vitro study characterizing cellular composition, growth factor kinetics and transcriptomic insights

BACKGROUND

Leukocyte- and platelet-rich fibrin (L-PRF) is an autologous platelet concentrate, prepared by centrifugation of blood and consisting of a dense fibrin network with incorporated leukocytes and platelets. This study aims to perform an in-depth analysis of the cells, growth factors, and transcriptome of L-PRF.

METHODS AND RESULTS

Fresh, 1 week and 2 weeks cultured human L-PRF membranes and liquid L-PRF glue were characterized on cellular and transcriptional level using flow cytometry (n = 4), single-cell RNA sequencing (n = 5) and RT-qPCR. Growth factor kinetics were investigated using ELISA (EGF, VEGF, PDGF-AB, TGF-β1, bFGF). L-PRF contained a large number of viable cells (fresh 97.14 ± 1.09%, 1 week cultured 93.57 ± 1.68%), mainly granulocytes in fresh samples (53.9 ± 19.86%) and T cells in cultured samples (84.7 ± 6.1%), confirmed with scRNA-seq. Monocytes differentiate to macrophages during 1 week incubation. Specifically arterial L-PRF membranes were found to release significant amounts of VEGF, EGF, PDGF-AB and TGF-β1.

CONCLUSION

We characterized L-PRF using in vitro experiments, to obtain an insight in the composition of the material including a possible mechanistic role for tissue healing. This was the first study characterizing L-PRF at a combined cellular, proteomic, and transcriptional level.

The effectiveness of autologous platelet-rich concentrates as an adjunct during nonsurgical periodontal therapy: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To evaluate the efficacy of autologous platelet concentrates (APC) on periodontal outcomes in nonsurgical therapy of periodontitis patients.

METHOD

Electronic search via Web of Science, MEDLINE via PubMed, Scopus, and Cochrane CENTRAL registry as well as manual search were done from June 2024 to July 2024 for relevant publication from inception until June 2024. The articles were assessed by 2 independent reviewers and deemed relevant when the interventional studies reported on periodontal outcomes after adjunctive APC were used in NSPT. The studies were excluded if it was not in English or unpublished. The risk of bias for each study was assessed using the Cochrane risk-of-bias tool (RoB 2). Fixed effect meta-analysis was conducted to measure the summary effect for change of periodontal pocket depth (PPD) and Clinical Attachment Level (CAL). The statistical heterogeneity between studies was also calculated using I2 test.

RESULT

A total of 607 records were found in the four electronic databases. Following the removal of duplicates and initial title screening, 16 full text articles from electronic search and 7 articles from manual search were assessed resulting in 13 studies included in the systematic review. The overall risk of bias showed most studies have moderate to high risk of bias. The fixed-effect meta-analysis showed summary effects favored the adjunctive use of APC in nonsurgical periodontal therapy but with high heterogeneity between the studies, particularly for CAL.

CONCLUSION

The evidence on APC as adjunct in NSPT is limited by the small number of studies, moderate to high risk of bias in most studies and significant heterogeneity in the results.

Management of Patients Receiving Anticoagulation Therapy in Dental Practice: A Systematic Review

BACKGROUND

Anticoagulant drugs are a valuable tool for minimizing thrombotic risks in at-risk patients. The purpose of this study is to conduct a literature review highlighting the management of these drugs during daily clinical dental practice.

MATERIALS AND METHODS

We limited our search to English-language papers published between 1 January 1989, and 7 March 2024, in PubMed, Scopus and Web of Science that were relevant to our topic. In the search approach, the Boolean keywords "anticoagulant AND dentistry" were used.

RESULTS

Twenty-five clinical trials were included for final review from 623 articles obtained from the databases Web of Science (83), PubMed (382), and Scopus (158), eliminating duplicates and 79 off-topic items, resulting in 419 articles after removing 315 entries and confirming eligibility. Overall, these studies support the use of local hemostatic measures to manage the risk of bleeding in patients on anticoagulant therapy undergoing dental procedures and highlight the importance of greater education and collaboration among healthcare professionals.

CONCLUSIONS

Research and clinical investigation have improved understanding and management of dental procedures in patients undergoing anticoagulant or antiplatelet therapy. Hemostatic agents, clinical protocols, risk factors, and continuous education are essential for navigating the complexities of anticoagulant therapy, ensuring optimal outcomes and enhancing patient well-being.