Emerging roles of platelet concentrates and platelet-derived extracellular vesicles in regenerative periodontology and implant dentistry

Therapeutic Potential of Extracellular Vesicles in Oral Inflammation

The therapeutic potential of extracellular vesicles (EVs) in reducing oral inflammation is thoroughly examined in this review, with an emphasis on gingivitis, periodontitis, and oral mucositis. It explains the complex relationship between microbial dysbiosis and host immune responses in the aetiology of oral inflammation. Pathophysiological mechanisms of periodontitis are examined, emphasising the roles played by periodontal pathogens and inflammatory mediators in the disease's chronic course and systemic effects. Preclinical research is providing new evidence that EVs originating from various cellular sources control immune cell dynamics towards a pro-healing phenotype, promote tissue regeneration, and have immunomodulatory qualities. EV-based therapies appear to be a promising new therapeutic technique with potential benefits over traditional methods for the treatment of oral inflammatory illnesses by specifically altering inflammatory signalling pathways. This review highlights the potential of EVs to improve patient outcomes in oral health and emphasises the need for additional clinical research to clarify the therapeutic efficacy and underlying mechanisms of EVs in periodontal therapy.

Efficacy of different forms of concentrated growth factors combined with deproteinized bovine bone minerals in guided bone regeneration: a randomized clinical trial

OBJECTIVES

To explore the bone regeneration effect of different forms of concentrated growth factor (CGF) when combined with deproteinized bovine bone mineral (DBBM) for simultaneous implant-guided bone regeneration (GBR) and its impact on postoperative adverse reactions.

METHODS

Fifty-seven patients who underwent simultaneous implant GBR were selected for the study and divided into three groups. The study involved three groups: the gel phase concentrated growth factor (GPCGF) group, which used GPCGF-DBBM mixture; the liquid phase concentrated growth factor (LPCGF) group, which used LPCGF-DBBM mixture; and the control group, which used DBBM alone. The thickness of the buccal lateral bones was measured using cone beam computed tomography (CBCT), and patients were asked to complete questionnaires to assess primary adverse reactions during the first week after surgery. The data were analyzed using one-way ANOVA, Tukey test, and Kruskal-Wallis test.

RESULTS

The buccal lateral bone thickness in the GPCGF, LPCGF, and control groups decreased significantly at 6 months post-surgery compared to immediately after surgery. The change of bone thickness in the GPCGF group was lower than that in the control group (p < 0.01), and that in the LPCGF group did not differ from that in the control group (p > 0.05). During the postoperative week, statistically significant differences could be observed in bleeding, mouth opening, chewing, sleeping, speaking, daily routine, and pain (p < 0.05).

CONCLUSIONS

Compared to the DBBM applied alone, the GPCGF-DBBM mixture has more positive implications for reducing bone resorption, promoting bone reconstruction and relieving certain postoperative adverse effects in dental implants with simultaneous GBR. The GPCGF-DBBM mixture was superior to the LPCGF-DBBM mixture in alleviating adverse effects in terms of bleeding and speaking after GBR.

CLINICAL TRIALS REGISTRATION NUMBER

The Chinese Clinical Trial Registry, NO. ChiCTR2300070107 (03/04/2023).

Autologous and Heterologous Minor and Major Bone Regeneration with Platelet-Derived Growth Factors

AIM

This review aims to explore the clinical applications, biological mechanisms, and potential benefits of concentrated growth factors (CGFs), autologous materials, and xenografts in bone regeneration, particularly in dental treatments such as alveolar ridge preservation, mandibular osteonecrosis, and peri-implantitis.

MATERIALS AND METHODS

A systematic literature search was conducted using databases like PubMed, Scopus, and Web of Science, with keywords such as "bone regeneration" and "CGF" from 2014 to 2024. Only English-language clinical studies involving human subjects were included. A total of 10 studies were selected for qualitative analysis. Data were processed through multiple stages, including title and abstract screening and full-text evaluation.

CONCLUSION

The findings of the reviewed studies underscore the potential of the CGF in enhancing bone regeneration through stimulating cell proliferation, angiogenesis, and extracellular matrix mineralization. Autologous materials have also demonstrated promising results due to their biocompatibility and capacity for seamless integration with natural bone tissue. When combined with xenografts, these materials show synergistic effects in improving bone quantity and quality, which are crucial for dental implant success. Future research should focus on direct comparisons of different techniques, the optimization of protocols, and broader applications beyond dental medicine. The integration of CGFs and autologous materials into routine clinical practice represents a significant advancement in regenerative dental medicine, with the potential for improved patient outcomes and satisfaction.

The potential utilization of platelet-derived extracellular vesicles in clinical treatment

Platelet-derived extracellular vesicles (PEVs) are released by platelets in the blood circulation, which carry a rich bio-molecular cargo influential in intercellular communications. PEVs can enter the lymph, bone marrow, and synovial fluid as nano-sized particles, while platelets cannot cross tissue barriers. Considering the advantages of PEVs such as low immunogenicity, high regulation of signal transduction, and easy obtainment, PEVs may be promising therapeutic tools for medical applications. The exceptional functional roles played by PEVs explain the recent interest in exploring new cell-free therapies that could address needs in angiogenesis, regenerative medicine, and targeted drug delivery. The review takes a critical look at the main advances of PEVs in the treatment of diseases by presenting the latest knowledge from the performed studies, in order to enhance the further translation of the PEVs research into feasible therapeutic applications.

Extracellular vesicles as therapeutic tools in regenerative dentistry

Dental and maxillofacial diseases are always accompanied by complicated hard and soft tissue defects, involving bone, teeth, blood vessels and nerves, which are difficult to repair and severely affect the life quality of patients. Recently, extracellular vesicles (EVs) secreted by all types of cells and extracted from body fluids have gained more attention as potential solutions for tissue regeneration due to their special physiological characteristics and intrinsic signaling molecules. Compared to stem cells, EVs present lower immunogenicity and tumorigenicity, cause fewer ethical problems, and have higher stability. Thus, EV therapy may have a broad clinical application in regenerative dentistry. Herein, we reviewed the currently available literature regarding the functional roles of EVs in oral and maxillofacial tissue regeneration, including in maxilla and mandible bone, periodontal tissues, temporomandibular joint cartilage, dental hard tissues, peripheral nerves and soft tissues. We also summarized the underlying mechanisms of actions of EVs and their delivery strategies for dental tissue regeneration. This review would provide helpful guidelines and valuable insights into the emerging potential of EVs in future research and clinical applications in regenerative dentistry.

Can concentrated growth factor prevent postoperative complications of impacted third molar surgery? A split-mouth randomized double-blind trial

OBJECTIVES

The purpose of the present study was to evaluate the effect of concentrated growth factor (CGF) on prevention of postoperative complications in the impacted third molar extraction.

MATERIALS AND METHODS

A total of 25 healthy patients with symmetrical bilaterally impacted third molars (50 extraction sites) were enrolled in this split-mouth, randomized, double-blind clinical trial. Third molar extractions were performed in both sites of the mandible at the same appointment. Randomization was performed using a coin toss to choose the test and control sites. CGF was placed in the extraction socket and the socket was sutured (test group), while the contralateral socket was only sutured (control group). Each patient acted as their own control. The primary outcome were pain assessed by visual analog scale (VAS) and facial swelling on the1st, 3rd and 7th postoperative days. The secondary outcomes were bone healing in extraction sockets through alveolar bone height (ABH) and alveolar bone density (ABD) evaluated by cone beam computed tomography (CBCT) immediately after extraction and in the 3rd and 6th months.

RESULTS

Twenty-five patients (12 female, 13 male; mean age 29.17) with bilateral impacted third molars participated in the study. A statistically significant reduction in pain was determined on the 3rd and 7th postoperative days in the CGF sites compared to the control sites while no statistically significant difference was found between the groups on the 1st postoperative day (3rd day, p = 0.009; 7th day, p = 0.039). There were no statistically significant differences in facial swelling and bone healing between the test and control groups at different time intervals, although the data obtained were slightly favoring the CGF group (p > 0.05). There were no serious adverse effects such as infection, alveolitis, paraesthesia, fracture through the follow-up period in all of the cases.

CONCLUSION

The study has demonstrated the effect of CGF on relieving the severity of pain after the third molar extraction.

CLINICAL RELEVANCE

Placement of CGF in the extraction socket could relieve postoperative pain and reduce patient discomfort after the third molar extraction. CGF is recommended during the third molar extraction due to its good biological effects, low cost and simple preparation procedures.

TRIAL REGISTRATION NUMBER

ChiCTR2300077819.

Using autogenous tooth sticky bone graft repair mandibular third molar dentigerous cyst osseous defects

BACKGROUND

Dentigerous cyst are most common odontogenic cyst and they frequently occur at the mandibular third molar. Their asymptomatic long medical history always resulted in severe bone resorption at the distal aspect of the adjacent second molar. BonMaker® ATB demonstrate an excellent autogenous bone graft candidacy. The aim of this study is to share a single team's experience of dentigerous cyst osseous defect repairing by applying autogenous tooth sticky bone graft.

METHOD

In total, 18 patients with dentigerous cyst, which was arised from mandibular third molar unilaterally, were enrolled in this study. Enucleation of dentigerous cyst was performed extracting with involving teeth under general anesthesia. Autogenous tooth sticky bone graft was prepared using extracted tooth and autogenous fibrin glue. Subsequently, grafting was performed above covering with concentrate growth factors. Patients were followed up at sixth months.

RESULTS

They were eleven male and seven female patients. Their ages ranged from 20 to 40 years, with a mean of 31 years. Primary wound healing of all sites was achieved in all the patients. Sixth months postoperative radiographic assessment show that dentigerous cysts osseous defects of seventeen patients were good bone filling and ossification. One patient occurred slight bone resorption at the distal aspect of the adjacent second molar.

CONCLUSION

Within the limitation of sample size and retrospective nature of the present study, autogenous tooth sticky bone graft demonstrates one of the best alternative alveolar bones repairing graft.

Effect of adjuvant autologous platelet concentrates on secondary repair of alveolar clefts: A systematic review and meta-analysis

OBJECTIVE

To review the existing evidence on the adjuvant use of autologous platelet concentrates (APCs) with iliac crest bone graft (ICBG) in the reconstruction of the secondary alveolar cleft.

METHODS

Electronic databases were searched systematically until November 2022. Clinical trials comparing the three-dimensional radiological outcomes of patients who underwent secondary alveolar bone grafting (SABG) with ICBG and APCs to those with ICBG alone and the radiological outcomes assessed 6 months after surgery were included. Two authors performed the study selection and the assessment of the risk of bias. Meta-analysis was performed using the random-effects model to determine the risk ratio (RR) for developing wound dehiscence and the mean difference (MD) with a 95% confidence interval (CI) for the percentage of newly formed bone.

RESULTS

Nine studies (seven RCT and two CCT) were included with a low to high risk of bias. At the 6-month follow-up, the study group revealed insignificant results regarding the percentage of newly formed bone (MD = 6.49; 95% CI: -0.97, 13.94; p = .09; χ2  = 0.01; I2  = 71%). In addition, the overall risk of developing wound dehiscence was lower in the study group (RR = 0.34; 95% CI: 0.15, 0.78; p = .01; χ2  = 0.67; I2  = 0%).

CONCLUSION

Currently, there is insufficient evidence to support the adjuvant use of APCs with ICBG on enhanced bone regeneration following secondary alveolar bone grafting. However, combining ICBG and APCs might be beneficial in reducing the risk of developing wound dehiscence.

Periodontal Guided Tissue Regeneration Membranes: Limitations and Possible Solutions for the Bottleneck Analysis

Guided tissue regeneration (GTR) is an important surgical method for periodontal regeneration. By placing barrier membrane on the root surface of the tooth to guide the adhesion and proliferation of periodontal ligament cells, periodontal tissue regeneration can be achieved. This review intends to analyze the current limitations of GTR membranes and to propose possible solutions for developing new ones. Limitations of current GTR membranes include nonabsorbable membranes and absorbable synthetic polymer membranes exhibit weak biocompatibility; when applying to a large defect wound, the natural collagen membrane with fast degradation rate have limited mechanical strength, and the barrier function may not be maintained well. Although the degradation time can be prolonged after cross-linking, it may cause foreign body reaction and affect tissue integration; The clinical operation of current barrier membranes is inconvenient. In addition, most of the barrier membranes lack bioactivity and will not actively promote periodontal tissue regeneration. Possible solutions include using electrospinning (ELS) techniques, nanofiber scaffolds, or developing functional gradient membranes to improve their biocompatibility; adding Mg, Zn, and/or other metal alloys, or using 3D printing technology to improve their mechanical strength; increasing the concentration of nanoparticles or using directional arrangement of membrane fibers to control the fiber diameter and porosity of the membrane, which can improve their barrier function; mixing natural and synthetic polymers as well as other biomaterials with different degradation rates in proportion to change the degradation rate and maintain barrier function; to improve the convenience of clinical operation, barrier membranes that meets personalized adhesion to the wound defect can be manufactured; developing local controlled release drug delivery systems to improve their bioactivity. Impact statement This review provides an up-to-date summary of commonly commercial periodontal guided tissue regeneration membranes, and analyze their limitations in clinical use. Using studies published recently to explore possible solutions from several perspectives and to raise possible strategies in the future. Several strategies have tested in vivo/in vitro, which will guide the way to propel clinical translation, meeting clinical needs.

Advances in Platelet Rich Plasma-Derived Extracellular Vesicles for Regenerative Medicine: A Systematic-Narrative Review

The use of platelet-rich plasma (PRP) has gained increasing interest in recent decades. The platelet secretome contains a multitude of growth factors, cytokines, chemokines, and other biological biomolecules. In recent years, developments in the field of platelets have led to new insights, and attention has been focused on the platelets' released extracellular vesicles (EVs) and their role in intercellular communication. In this context, the aim of this review was to compile the current evidence on PRP-derived extracellular vesicles to identify the advantages and limitations fortheir use in the upcoming clinical applications. A total of 172 articles were identified during the systematic literature search through two databases (PubMed and Web of Science). Twenty publications met the inclusion criteria and were included in this review. According to the results, the use of PRP-EVs in the clinic is an emerging field of great interest that represents a promising therapeutic option, as their efficacy has been demonstrated in the majority of fields of applications included in this review. However, the lack of standardization along the procedures in both the field of PRP and the EVs makes it extremely challenging to compare results among studies. Establishing standardized conditions to ensure optimized and detailed protocols and define parameters such as the dose or the EV origin is therefore urgent. Further studies to elucidate the real contribution of EVs to PRP in terms of composition and functionality should also be performed. Nevertheless, research on the field provides promising results and a novel basis to deal with the regenerative medicine and drug delivery fields in the future.

Nanomaterials for Periodontal Tissue Regeneration: Progress, Challenges and Future Perspectives

Bioactive nanomaterials are increasingly being applied in oral health research. Specifically, they have shown great potential for periodontal tissue regeneration and have substantially improved oral health in translational and clinical applications. However, their limitations and side effects still need to be explored and elucidated. This article aims to review the recent advancements in nanomaterials applied for periodontal tissue regeneration and to discuss future research directions in this field, especially focusing on research using nanomaterials to improve oral health. The biomimetic and physiochemical properties of nanomaterials such as metals and polymer composites are described in detail, including their effects on the regeneration of alveolar bone, periodontal ligament, cementum and gingiva. Finally, the biomedical safety issues of their application as regenerative materials are updated, with a discussion about their complications and future perspectives. Although the applications of bioactive nanomaterials in the oral cavity are still at an initial stage, and pose numerous challenges, recent research suggests that they are a promising alternative in periodontal tissue regeneration.

The Experimental Study of Periodontal Ligament Stem Cells Derived Exosomes with Hydrogel Accelerating Bone Regeneration on Alveolar Bone Defect

INTRODUCTION

this study was conducted to investigate the osteogenic ability of periodontal ligament stem cells (PDLSCs) derived exosomes (PDLSCs-Exos) and the effect of PDLSCs-Exos with hydrogel on alveolar bone defect repairment in the rat.

METHODS

the PDLSCs were obtained through primary cell culture, and PDLSCs-Exos were purified by the ultracentrifugation method. The CCK-8 kit and ALP staining were used to explore the effect of PDLSCs-Exos on promoting the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). In vivo, the alveolar bone defect models were made mesial to the bilateral maxillary first molars of rats. MicroCT, HE staining, and Masson staining were used to analyze the new bone at the bone defect of rats.

RESULTS

the periodontal ligament stem cells and the periodontal ligament stem cells derived exosomes were successfully extracted. The results of the CCK-8 kit and ALP staining showed PDLSCs-Exos significantly promoted the proliferation osteogenic differentiation of BMSCs. In vivo experiment results revealed that compared with the control group and the hydrogel group, the rats in the hydrogel with exosomes group showed more new bone formation in alveolar bone defects.

CONCLUSION

Periodontal ligament stem cells and exosomes derived from periodontal ligament stem cells were successfully extracted. The results demonstrated that the hydrogel successfully delivered periodontal ligament stem cells derived exosomes for repairing alveolar bone defects in rats in vivo at the initial stage.