Mechanical properties and cellular content of leukocyte- and platelet-rich fibrin membranes of patients on antithrombotic drugs

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2022 dental literature to briefly touch on several topics of interest to modern restorative dentistry. Each committee member brings discipline-specific expertise in their subject areas that include (in order of the appearance in this report): prosthodontics; periodontics, alveolar bone, and peri-implant tissues; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence the daily dental treatment decisions of the reader with an emphasis on innovations, new materials and processes, and future trends in dentistry. With the tremendous volume of literature published daily in dentistry and related disciplines, this review cannot be comprehensive. Instead, its purpose is to update interested readers and provide valuable resource material for those willing to subsequently pursue greater detail on their own. Our intent remains to assist colleagues in navigating the tremendous volume of newly minted information produced annually. Finally, we hope that readers find this work helpful in managing patients.

The Effect of Leukocyte- and Platelet-Rich Fibrin on Central and Peripheral Nervous System Neurons-Implications for Biomaterial Applicability

Leukocyte- and Platelet-Rich Fibrin (L-PRF) is a second-generation platelet concentrate that is prepared directly from the patient's own blood. It is widely used in the field of regenerative medicine, and to better understand its clinical applicability we aimed to further explore the biological properties and effects of L-PRF on cells from the central and peripheral nervous system. To this end, L-PRF was prepared from healthy human donors, and confocal, transmission, and scanning electron microscopy as well as secretome analysis were performed on these clots. In addition, functional assays were completed to determine the effect of L-PRF on neural stem cells (NSCs), primary cortical neurons (pCNs), and peripheral dorsal root ganglion (DRG) neurons. We observed that L-PRF consists of a dense but porous fibrin network, containing leukocytes and aggregates of activated platelets that are distributed throughout the clot. Antibody array and ELISA confirmed that it is a reservoir for a plethora of growth factors. Key molecules that are known to have an effect on neuronal cell functions such as brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), vascular endothelial growth factor (VEGF), and platelet-derived growth factor (PDGF) were slowly released over time from the clots. Next, we found that the L-PRF secretome had no significant effect on the proliferative and metabolic activity of NSCs, but it did act as a chemoattractant and improved the migration of these CNS-derived stem cells. More importantly, L-PRF growth factors had a detrimental effect on the survival of pCNs, and consequently, also interfered with their neurite outgrowth. In contrast, we found a positive effect on peripheral DRG neurons, and L-PRF growth factors improved their survival and significantly stimulated the outgrowth and branching of their neurites. Taken together, our study demonstrates the positive effects of the L-PRF secretome on peripheral neurons and supports its use in regenerative medicine but care should be taken when using it for CNS applications.

Clinical applications of mucogingival therapies utilizing adjunctive autologous blood products

BACKGROUND

Mucogingival deformities are prevalent oral conditions and can result in esthetic compromise, dentinal hypersensitivity, and an increase in radicular caries rates. Mucogingival treatments address thin periodontal phenotype and/or gingival recession defects. Although many of these grafting procedures are predictable in improving soft-tissue quality and quantity around teeth and dental implants, patients often complain of discomfort at both the donor and recipient sites. Free gingival grafts and coronally advanced flaps alone or in combination with subepithelial connective tissue graft and/or acellular dermal matrix are among the most common surgical procedures employed to achieve root coverage and enhance periodontal phenotype. Autologous blood products (ABPs) contain platelets, growth factors, leukocytes, and stem cells that contribute to cell mitosis, collagen production, and angiogenesis, leading to the healing and regeneration of hard and soft tissue. Evaluation of the adjunctive role of ABPs in mucogingival surgery and their impacts on clinical and patient-centered data is critical to achieve optimal patient-reported outcome measures based upon the current scientific evidence.

METHODS

We present exemplar cases in which adjunctive ABPs were utilized in mucogingival treatment to enhance treatment outcomes.

RESULTS

No adverse events were noted. Satisfactory treatment outcomes were achieved in patients with local and/or systemic compromise when mucogingival therapies were used in combination with ABPs.

CONCLUSIONS

Adjunctive use of ABPs may enhance outcomes of mucogingival therapy. Utilization of adjunctive ABPs may be particularly advantageous in situations where the predictability of clinical and esthetic outcomes is limited due to anatomical and/or patient factors.

Advances in Clinical and Molecular Research of Biomaterials in Dentistry: The New Era for Dental Applications

Biomaterials in dentistry play a fundamental role in the quality of regeneration mechanisms and in healing following different rehabilitation techniques [...]