Platelet-rich fibrin increases proliferation and differentiation of human dental pulp cells

Regenerative endodontic treatment and traumatic dental injuries

Pulp necrosis is the most common complication following dental trauma and is often associated with apical periodontitis. The management of these teeth is challenging in terms of large root canals, open apices, thin dentinal walls, and short roots. Over decades the conventional treatment for these teeth was calcium hydroxide apexification, a time-consuming procedure despite high success rates. Subsequently after the introduction of mineral trioxide aggregate and hydraulic calcium silicate materials single visit apical plug procedures became increasingly practiced with comparable success rates to the conventional apexification. The search continued afterward for a clinical procedure that may stimulate further root development and apical closure to avoid the long-term complication of root fracture after apexification. Regenerative procedures using stem cells derived from the apical papilla and blood clots as scaffolds were then introduced for the management of immature teeth, with variable protocols and success rates. This review will cover the evidence available and current position of regenerative endodontic procedures in traumatized immature teeth with apical periodontitis, in terms of clinical protocols, outcome, and potential prognostic factors.

Osteogenic potential of apical papilla stem cells mediated by platelet-rich fibrin and low-level laser

To evaluate the osteogenic potential of platelet-rich fibrin (PRF) and low-level laser therapy (LLLT) on human stem cells from the apical papilla (SCAP) we isolated, characterized, and then cultured in an osteogenic medium cells with PRF and/or LLLT (660 nm, 6 J/m2-irradiation). Osteogenic differentiation was assessed by bone nodule formation and expression of bone morphogenetic proteins (BMP-2 and BMP-4), whereas the molecular mechanisms were achieved by qRT-PCR and RNA-seq analysis. Statistical analysis was performed by ANOVA and Tukey's post hoc tests (p < 0.05* and p < 0.01**). Although PRF and LLLT increased bone nodule formation after 7 days and peaked at 21 days, the combination of PRF + LLLT led to the uppermost nodule formation. This was supported by increased levels of BMP-2 and -4 osteogenic proteins (p < 0.005). Furthermore, the PRF + LLLT relative expression of specific genes involved in osteogenesis, such as osteocalcin, was 2.4- (p = 0.03) and 28.3- (p = 0.001) fold higher compared to the PRF and LLLT groups, and osteopontin was 22.9- and 1.23-fold higher, respectively (p < 0.05), after 7 days of interaction. The transcriptomic profile revealed that the combination of PRF + LLLT induces MSX1, TGFB1, and SMAD1 expression, after 21 days of osteogenic differentiation conditions exposition. More studies are required to understand the complete cellular and molecular mechanisms of PRF plus LLLT on stem cells. Overall, we demonstrated for the first time that the combination of PRF and LLLT would be an excellent therapeutic tool that can be employed for dental, oral, and craniofacial repair and other tissue engineering applications.

Advanced platelet rich fibrin demonstrates improved osteogenic induction potential in human periodontal ligament cells, growth factor production and mechanical properties as compared to leukocyte and platelet fibrin and injectable platelet rich fibrin

OBJECTIVES

This cross-sectional invitro research aimed to compare and contrast the macroscopic and microscopic, mechanical and biochemical features of leukocyte-rich platelet-rich fibrin, advanced platelet-rich fibrin, and injectable platelet-rich fibrin.

MATERIALS AND METHODS

In all, 150 samples were taken from males aged 18 to 25 with good systemic health (n = 50 each for i-PRF, A-PRF, and L-PRF). The samples were assessed for clot length, clot width, membrane length and width. Microscopic parameters assessed were the distribution of cells and fibrin structure. Mechanical tests were performed for tensile strength using a universal testing machine and growth factor analysis was performed for platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)- β on Days 1, 3 and 7 using commercially available ELISA kits. The osteogenic potential was analyzed in a culture of human periodontal ligament cells for 21 days using cell viability assay, alkaline phosphatase formation and alizarin red staining for mineralization.

RESULTS

L-PRF demonstrates statistically superior clot length, width, weight, membrane length, width and weight in comparison to A-PRF (p < 0.05). L-PRF demonstrates a denser fibrin structure in comparison to A-PRF and i-PRF (p < 0.05). The cells in L-PRF are most commonly situated in the proximal of the clot where as they are distributed in the proximal and middle aspect for A-PRF(p < 0.05). A-PRF demonstrates the highest tensile strength followed by L-PRF (p < 0.05). When growth factor release was evaluated, A-PRF showed noticeably increased release of all growth factors, namely PDGF-BB, TGF-ß, and VEGF, in comparison to i-PRF and L-PRF (p < 0.05). On days 7 and 14, the cell viability of human periodontal ligament cells in co-culture with A-PRF was statistically substantially greater than that of L-PRF and i-PRF (p < 0.05). Alkaline phosphatase levels were statistically substantially higher in A-PRF, followed by i-PRF and L-PRF on days 14 and 21 (p < 0.05). After 21 days of culture, A-PRF treated cultures had much more Alizarin Red staining than L-PRF and i-PRF cultures did (p < 0.05).

CONCLUSION

It was determined that although L-PRF exhibits greater size and weight in comparison to A-PRF and i-PRF, A-PRF has superior mechanical properties, increased growth factor releases of TGF-b, PDGF-BB, and VEGF as well as superior cell viability, alkaline phosphatase production, and mineralization on human periodontal ligament cells.

CLINICAL RELEVANCE

Based on these findings, A-PRF can be recommended for improved delivery of growth factors and osteogenesis whereas L-PRF is better-suited for applications relying on the size of membrane.

Multifunctional hydrogel/platelet-rich fibrin/nanofibers scaffolds with cell barrier and osteogenesis for guided tissue regeneration/guided bone regeneration applications

Periodontal defect seriously affects people's life health and quality. Guided tissue regeneration (GTR) and guided bone regeneration (GBR) have made great progress in periodontal disease treatment, but some deficiencies existed in commercial materials of GTR and GBR. For obtaining better therapeutic effects, multifunctional composite scaffolds containing different biological macromolecules were developed in this study. Chitosan/poly (γ-glutamic acid)/nano-hydroxyapatite hydrogels (CP/nHA) made by electrostatic interactions and lyophilization were filled in the bone defects to achieve osteogenesis. Platelet-rich fibrin (PRF) extracted from blood could accelerate bone formation by releasing various bioactive substances as middle layer of composite scaffolds. Polycaprolactone/gelatin nanofibers (PG) prepared by electrospinning were attached to the junction of soft and hard tissue, which could prevent fibrous tissue from infiltrating into bone defects. The composite scaffolds showed good morphology, biocompatibility, cell barriers and osteogenic differentiation in vitro. The excellent ability of bone formation was verified by implantation of triple-layered composite scaffolds into alveolar bone defects in rabbit in vivo. The hierarchical structure was conducive to personalized customization to meet the needs of different defects. All in all, the multifunctional scaffolds could play important roles of GTR and GBR in alveolar bone regeneration and provide good application prospect for bone repair in clinic.

The Effects of Platelet-Rich Fibrin in the Behavior of Mineralizing Cells Related to Bone Tissue Regeneration-A Scoping Review of In Vitro Evidence

Platelet-rich fibrin (PRF) is a second-generation blood concentrate that serves as an autologous approach for both soft and hard tissue regeneration. It provides a scaffold for cell interaction and promotes the local release of growth factors. PRF has been investigated as an alternative to bone tissue therapy, with the potential to expedite wound healing and bone regeneration, though the mechanisms involved are not yet fully understood. This review aims to explore the in vitro evidence of PRF's effects on the behavior of mineralizing cells related to bone tissue regeneration. A systematic electronic search was conducted up to August 2023, utilizing three databases: PubMed, Web of Science, and Scopus. A total of 76 studies were selected, which presented in vitro evidence of PRF's usefulness, either alone or in conjunction with other biomaterials, for bone tissue treatment. PRF membranes' influence on the proliferation, differentiation, and mineralization of bone cells is linked to the constant release of growth factors, resulting in changes in crucial markers of bone cell metabolism and behavior. This further reinforces their therapeutic potential in wound healing and bone regeneration. While there are some notable differences among the studies, the overall results suggest a positive effect of PRF on cell proliferation, differentiation, mineralization, and a reduction in inflammation. This points to its therapeutic potential in the field of regenerative medicine. Collectively, these findings may help enhance our understanding of how PRF impacts basic physiological processes in bone and mineralized tissue.

Macro, Micro, and Nano-Inspired Bioactive Polymeric Biomaterials in Therapeutic, and Regenerative Orofacial Applications

Introducing dental polymers has accelerated biotechnological research, advancing tissue engineering, biomaterials development, and drug delivery. Polymers have been utilized effectively in dentistry to build dentures and orthodontic equipment and are key components in the composition of numerous restorative materials. Furthermore, dental polymers have the potential to be employed for medication administration and tissue regeneration. To analyze the influence of polymer-based investigations on practical medical trials, it is required to evaluate the research undertaken in this sector. The present review aims to gather evidence on polymer applications in dental, oral, and maxillofacial reconstruction.

Histologic comparison of formocresol, platelet-rich fibrin, and hesperidin in pulpotomy: A randomized trial in dogs

Aims

To histologically assess and compare formocresol (FC), platelet-rich fibrin (PRF), and hesperidin (HPN) as pulpotomy agents in dogs.

Materials and Methods

Pulpotomy was attempted from the buccal surface (class V) of 48 teeth in three mongrel dogs (Canis Lupus). Cavities were randomly allocated for three groups (n = 16) according to the pulpotomy agent used; (group I: FC (control), group II: PRF, and group III: HPN). All cavities were then sealed with zinc oxide eugenol followed by resin-modified glass ionomer restoration. Two months later, dogs were euthanized; the specimens were obtained and prepared for histological assessment followed by statistical analysis.

Results

HPN specimens showed the best dentin bridge formation and the least inflammatory signs and pulp disorganization. Followed without statistically significant difference by PRF (P ≥ 0.05). Both of HPN and PRF, however, showed a significant difference statistically (P ≤ 0.05) to FC that showed no dentin bridging with more pronounced inflammation, necrosis, and pulp disorganization.

Conclusions

For pulpotomy, HPN and PRF seemed histologically to be good substitutes for FC in the dog model.

Combination Therapy of Antibiotics and Platelet-rich Fibrin for Apical Closure: Case Series

The aim of endodontic treatment in immature teeth is to disinfect and regenerate tissues in the apical region for the closure of the root. Stem cells from apical papilla (SCAP) by differentiating into odontogenic and osteogenic tissues create apical closure. Triple antibiotic pastes (TAP) disinfect the root canal without adversely affecting the SCAP. Differentiation of SCAP is promoted by platelet-rich fibrin (PRF). Hence, combining TAP and PRF could have a synergistic effect.

Case description

An 11-year-old girl, a 9-year-old boy, and a 13-year-old boy, symptomatic patients with open apex, are treated with TAP, PRF, and mineral trioxide aggregate (MTA) as an apical barrier sequentially. There was the formation of a calcific barrier at the end of 12, 6, and 3 months, respectively.

Conclusion

Correct diagnosis and protocol of sequential disinfection, regeneration, and finally filling the canal with an apical barrier could yield better results.

How to cite this article

Biradar N, Ragulakollu R, Tej G, et al. Combination Therapy of Antibiotics and Platelet-rich Fibrin for Apical Closure: Case Series. Int J Clin Pediatr Dent 2023;16(3):541-546.

The development of a dental light curable PRFe-loaded hydrogel as a potential scaffold for pulp-dentine complex regeneration: An in vitro study

AIM

The study aimed to develop a bicomponent bioactive hydrogel formed in situ and enriched with an extract of platelet-rich fibrin (PRFe) and to assess its potential for use in pulp-dentine complex tissue engineering via cell homing.

METHODOLOGY

A bicomponent hydrogel based on photo-activated naturally derived polymers, methacrylated chitosan (ChitMA) and methacrylated collagen (ColMA), plus PRFe was fabricated. The optimized formulation of PRFe-loaded bicomponent hydrogel was determined by analysing the mechanical strength, swelling ratio and cell viability simultaneously. The physical, mechanical, rheological and morphological properties of the optimal hydrogel with and without PRFe were determined. Additionally, MTT, phalloidin/DAPI and live/dead assays were carried out to compare the viability, cytoskeletal morphology and migration ability of stem cells from the apical papilla (SCAP) within the developed hydrogels with and without PRFe, respectively. To further investigate the effect of PRFe on the differentiation of encapsulated SCAP, alizarin red S staining, RT-PCR analysis and immunohistochemical detection were performed. Statistical significance was established at p <  .05.

RESULTS

The optimized formulation of PRFe-loaded bicomponent hydrogel can be rapidly photocrosslinked using available dental light curing units. Compared to bicomponent hydrogels without PRFe, the PRFe-loaded hydrogel exhibited greater viscoelasticity and higher cytocompatibility to SCAP. Moreover, it promoted cell proliferation and migration in vitro. It also supported the odontogenic differentiation of SCAP as evidenced by its promotion of biomineralization and upregulating the gene expression for ALP, COL I, DSPP and DMP1 as well as facilitated angiogenesis by enhancing VEGFA gene expression.

CONCLUSIONS

The new PRFe-loaded ChitMA/ColMA hydrogel developed within this study fulfils the criteria of injectability, cytocompatibility, chemoattractivity and bioactivity to promote odontogenic differentiation, which are fundamental requirements for scaffolds used in pulp-dentine complex regeneration via cell-homing approaches.

Leukocyte-Rich and Platelet-Rich Fibrin for Skull Base Reconstruction After Endoscopic Endonasal Skull Base Surgery

BACKGROUND

Postoperative cerebrospinal fluid (CSF) leak is one of the most common complications after endoscopic endonasal approach to the skull base.

OBJECTIVE

To analyze the effect of leukocyte-rich and platelet-rich fibrin (L-PRF) as part of a standardized endonasal skull base repair protocol on postoperative infection and CSF leak rate.

METHODS

One hundred three patients who underwent an endoscopic endonasal approach and were reconstructed using a standard technique (Group A) were compared with 139 patients using the same protocol with the addition of L-PRF (Group B). Postoperative intracranial infection and CSF leak at 6 months were analyzed.

RESULTS

In patients with intraoperative CSF leak, postoperative leak occurred in 10.8% in Group A and 2.6% in Group B ( P .024), and in patients with intraoperative high-flow leaks, the incidences were 11.7% and 3.1%, respectively ( P .048). L-PRF reduced postoperative CSF leak by 76% in cases with intraoperative CSF leak (relative risk 0.24, 95% CI 0.06-0.87) and by 73% of patients with high-flow leak (relative risk 0.27, 95% CI 0.07-0.99). In patients undergoing surgery for diagnoses other than adenomas, there were no cases of postoperative leak in Group B, whereas in Group A occurred in 13.4% of those with intraoperative leaks ( P .047) and 15.8% with high-flow intraoperative leaks ( P .033). No significant differences were found in patients with pituitary adenoma. Meningitis occurred in 0.97% in Group A vs 2.16% in Group B ( P .639), without differences between subgroups.

CONCLUSION

L-PRF reduced the rate of postoperative CSF leaks in patients with intraoperative leaks, without differences on postoperative meningitis.

Microstructure and color stability of calcium silicate-based dental materials exposed to blood or platelet-rich fibrin

OBJECTIVES

To investigate the effects of blood and platelet-rich fibrin (PRF), commonly used scaffolds in regenerative endodontic treatment (RET), on the hydration, microstructure, and color stability of three hydraulic calcium silicate cements (HCSCs), OrthoMTA, RetroMTA, and TotalFill-BC-RRM.

MATERIALS AND METHODS

The HCSCs were prepared and placed into polyethylene molds and transferred to Eppendorf tubes containing PRF, blood, or PBS and then incubated for 1 week or 1 month. The microstructure and hydration of the cements were studied by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The chromatic alteration of materials was also measured using a spectrophotometer. The data for color stability were analyzed using 2-way analysis of variance and Tukey post hoc tests.

RESULTS

There was no significant difference between the color stability of cements exposed to PBS (p > 0.05). The chromatic alteration of cements exposed to blood was significantly greater than those exposed to PRF and PBS (p < 0.001). In the presence of blood and PRF, the color change of OrthoMTA was significantly greater than that of RetroMTA and TotalFill (p < 0.05), with no significant difference between RetroMTA and TotalFill (p > 0.05). XRD analysis of all cements revealed a calcium hydroxide peak after 1-week and 1-month exposure to the media; however, OrthoMTA and TotalFill exposed to blood and PRF for 1 month showed weaker calcium hydroxide peaks. SEM images revealed cements exposed to PBS had a different surface microstructure compared to those exposed to blood and PRF. Furthermore, the surface microstructure of HCSCs was influenced by the type of cement radiopacifier (bismuth oxide or zirconium oxide). EDS analysis of the elemental composition in all groups displayed peaks of Ca, O, C, Si, P, and Al.

CONCLUSIONS

Color stability, hydration behavior, and microstructure of HCSCs were affected by exposure to PRF and blood and the type of cement radiopacifier.

CLINICAL RELEVANCE

As some important physicochemical properties of HCSCs could be influenced by the environmental conditions and the type of radiopacifier, alternatives to blood clot and HCSCs containing substitutes for bismuth oxide might be more suitable in RETs.

Regenerative Endodontics-Reviving the Pulp the Natural Way: A Case Report

Regenerative endodontic therapy (RET) offers a novel treatment option for developing teeth with pulp necrosis. In the current instance, RET was used to treat an immature mandibular permanent first molar that had been identified with irreversible pulpitis. The root canals were treated with triple antibiotic paste (TAP) and 1.5% sodium hypochlorite (NaOCl) irrigation. TAP was removed, and 17% ethylenediaminetetraacetic acid (EDTA) was used to treat the root canals during the second visit. As a scaffold, Platelet-rich fibrin (PRF) was applied. Mineral trioxide aggregate (MTA) was applied over PRF, and composite resin was used to repair the teeth. Radiographs taken from the posterior were utilized to assess the healing. The teeth displayed no signs of pain and healing after the six-month follow-up periods, and pulp sensibility tests using a cold and electric pulp tester produced no results. Conservative treatment options should be considered to save immature permanent teeth and assist in the regeneration of the root apex.

Comparative analysis of the effect of 4MATRIX with and without PRF on regeneration of infrabony periodontal pockets

Aim

The aim was to compare the effect in improvement of periodontal pocket depth (PPD) and clinical attachment level (CAL) between application of 4MATRIX and 4 MATRIX combined with PRF in advanced periodontal disease during follow-up of 6, 12 and 18 months.

Methods

Thirty patients of both genders aged 25-50 years were included. The patients were clinically and radiologically diagnosed with generalized advanced chronic periodontitis with the presence of periodontal pockets with a depth of ≥ 5 mm bilaterally in the upper jaw. Both sides were treated with a flap intervention in all patients. On one side a bone substitute 4MATRIX was applied, and the other side was treated with an application 4MATRIX and PRF. The clinical assessment and measurements were performed in four stages, immediately before the intervention, and then 6, 12 and 18 months after the intervention. PPD and CAL were determined in all four timepoints.

Results

PPD was the highest at zero time before the surgery for both groups and was 5.56 ± 0.28 mm. In the postoperative follow-up period, the PPD value decreased gradually with the lowest average value of 5.10 ± 0.18 mm after 18 months in Group I and 4.67 ± 0.13 mm in Group II (p < 0.001, respectively). Moreover, comparing the values of PPD at 6, 12 and 18 months after the surgery, a significant difference was found between the patients from the 4MATRIX vs 4MATRIX + PRF (p < 0.001 respectively). The postoperative follow-up period showed a decrease in CAL value with the lowest value after 18 months. A significant difference in CAL was found between the four measurement times (p < 0.001, respectively). The average level of CAL was the highest before surgical treatment in both groups. The intergroup analysis of CAL after 18 months in group I (4MATRIX) was 5.27 ± 0.17 mm and in group II 4.10 ± 0.14 mm (p < 0.001).

Conclusion

Treatment of adult patients with advanced chronic periodontitis with periodontal pockets of ≥ 5 mm bilaterally in the upper jaw using 4MATRIX and 4MATRIX + PRF showed improvement of PPD and lower CAL loss after 18 months of the treatment. In the group treated with 4MATRIX + PRF patients showed the highest improvement in PPD and CAL loss. The analysis of treatment with 4MATRIX and 4MATRIX + PRF showed the lowest values after 18 months of the treatment.

Analysis of Pulp Tissue Viability and Cytotoxicity of Pulp Capping Agents

The present research study assessed the cell viability and cytotoxic effect of mineral tri-oxide aggregate (MTA), Tetric N-Bond Universal bonding agent, Theracal PT (pulpotomy treatment), and platelet-rich fibrin (PRF) as pulp capping agents on human dental pulp stem cells (hDPSCs). The cells were isolated from the pulp tissue of an extracted healthy permanent third molar. After four passages in Dulbecco’s Modified Eagle’s Medium, the primary cells were employed for the investigation. The test materials and untreated cells (negative control) were subjected to an Methylthiazol-diphenyl-tetrazolium (MTT) cytotoxicity assay and assessed at 24-, 48-, and 72-h intervals. The Wilcoxon matched-paired t-test and Kruskal−Wallis analysis of variance (ANOVA) test were applied (p < 0.05). PRF imparted the highest cell viability at 48 h (p < 0.001), followed by MTA, Theracal PT, and Tetric N-Bond. Similarly, PRF had the highest potential to enhance cell proliferation and differentiation (p < 0.001), followed by Theracal PT, MTA, and the bonding agent at the end of 24 h and 72 h, respectively. Finally, PRF sustained the viability of human primary dental pulp stem cells more effectively than Theracal PT and MTA; however, the application of a Tetric N-Bond as a pulp capping agent was ineffective.

Synthesis, characterization, antioxidant potential, and cytotoxicity screening of new Cu(II) complexes with 4-(arylchalcogenyl)-1H-pyrazoles ligands

Two new Cu(II) complexes based on 4-(arylchalcogenyl)-1H-pyrazoles monodentate bis(ligand) containing selenium or sulfur groups (2a and 2b) have been synthesized and characterized by IR spectroscopy, high-resolution mass spectrometry (HRMS), and by X-ray crystallography. In the effort to propose new applications for the biomedical area, we evaluated the antioxidant activity and cytotoxicity of the newly synthesized complexes. The antioxidant activity of the Cu(II) complexes (2a - 2b) were assessed through their ability to inhibit the formation of reactive species (RS) induced by sodium azide and to scavenge the synthetic radicals 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS⁺). Both copper complexes containing selenium (2a) and sulfur (2b) presented in vitro antioxidant activity. The (1a - 1b and 2a - 2b) compounds did not show cytotoxicity in V79 cells at low concentrations. Furthermore, the antiproliferative activity of free ligands (1a - 1b) and their complexes (2a - 2b) were tested against two human tumor cell lines: MCF-7 (breast adenocarcinoma) and HepG2 (hepatocarcinoma). Also, 2a was tested against U2OS (osteosarcoma). Our results demonstrated that 1a and 1b show little or no growth inhibition activities on human cell lines.The 2a compound exhibited good cytotoxic activity toward human tumor cell lines. However, 2a showed no selectivity, with a selectivity index of 1.12-1.40. Complex 2b was selective for the MCF-7 human tumor cell lines with IC₅₀ of 59 ± 2 μM. This study demonstrates that the Cu(II) complexes 2a and 2b represent promising antitumoral compounds, and further studies are necessary to understand the molecular mechanisms of these effects.

A Bibliometric Analysis of Platelet-Rich Fibrin in Dentistry

Platelet-rich fibrin (PRF), a second-generation platelet concentrate, has been widely recognized in numerous studies for its performance of wound healing and regeneration in dentistry. However, bibliometric analysis of PRF in dentistry is still scarce. Thus, this study aimed to conduct and delineate a bibliometric analysis of the application of PRF and its changing trend in dentistry. All papers concerning PRF up to 30 June 2022 were included in the literature search from the Web of Science Core Collection database. These data were then entered into Microsoft Excel, analyzed by the SAS statistical software, and visualized by the VOSviewer software. A total of 562 articles were retrieved following the exclusive criteria. The results demonstrated that the trend of annual publication increased continually (p for trend < 0.01), more notably in the last five years. The majority of the articles were original (58.01%), followed by reviews (17.08%), and case reports (10.14%). The three major study designs were clinical studies (20.11%), randomized controlled trials (17.62%), and review/meta-analysis (17.08%). PRF was most frequently employed in oral surgery (31.14%), periodontal regeneration (22.42%), and implant therapy (18.68%). Turkey (16.19%), India (12.28%) and China (7.12%) were the top 3 countries publishing PRF studies. By comparing the total number of publications, total citation counts and varying counting methods, a combination of numerous counting methods was suggested for use since each counting method yields different results. Taken together, we hope with these informative findings, researchers could focus on the future direction or advancement in PRF, laying a foundation for evidence-based dentistry.

Advances in Scaffolds Used for Pulp-Dentine Complex Tissue Engineering - A Narrative Review

Pulp necrosis in immature teeth disrupts root development and predisposes roots to fracture as a consequence of their thin walls and open apices. Regenerative endodontics is a developing treatment modality whereby necrotic pulps are replaced with newly formed healthy tissue inside the root canal. Many clinical studies have demonstrated the potential of this strategy to stimulate root maturation and apical root-end closure. However, clinical outcomes are patient-dependent and unpredictable. The development of predictable clinical protocols is achieved through the interplay of the three classical elements of tissue engineering, namely, stem cells, signaling molecules, and scaffolds. Scaffolds provide structural support for cells to adhere and proliferate and also regulate cell differentiation and metabolism. Hence, designing and fabricating an appropriate scaffold is a crucial step in tissue engineering. In this review, four main classes of scaffolds used to engineer pulp-dentine complexes, including bioceramic-based scaffolds, synthetic polymer-based scaffolds, natural polymer-based scaffolds, and composite scaffolds, are covered. Additionally, recent advances in the design, fabrication, and application of such scaffolds are analysed along with their advantages and limitations. Finally, the importance of vascular network establishment in the success of pulp-dentine complex regeneration and strategies used to create scaffolds to address this challenge are discussed.

Do platelet concentrates accelerate orthodontic tooth movement?: a systematic review

PURPOSE

Surgical techniques in orthodontics have received widespread attention in recent years. Meanwhile, biomaterials with high molecular content have been introduced, such as platelet concentrates (PCs), which may accelerate orthodontic tooth movement (OTM) and reduce periodontal damage. The present systematic review aimed to answer the following PICO question: "In patients in whom orthodontic surgical techniques are performed (P), what is the effectiveness of using PCs over the surgical site (I) when compared to not placing PCs (C) to achieve faster tooth movement (O)?"

METHODS

A search was performed in 6 databases. The criteria employed were those described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses declaration. The present review included studies with a control group that provided information about the influence of PCs on the rate of OTM.

RESULTS

The electronic search identified 10 studies that met the established criteria.

CONCLUSIONS

The included studies were very diverse, making it difficult to draw convincing conclusions. However, a tendency was observed for OTM to be accelerated when PCs were used as an adjuvant for canine distalization after premolar extraction when distalization was started in the same session. Likewise, studies seem to indicate an association between PC injection and the amount of canine retraction. However, it is not possible to affirm that the use of PCs in corticotomy shortens the overall treatment time, as this question has not been studied adequately.

TRIAL REGISTRATION

PROSPERO Identifier: CRD42021278542.

Evaluation of the Effectiveness of Laser-Assisted Bleaching of the Teeth Discolored due to Regenerative Endodontic Treatment

Regenerative endodontic treatments (RETs) as a valuable treatment option to save the immature necrotic teeth, have been reported to be associated with discoloration which is an inevitable unfavorable outcome. The present study aimed to compare three laser-assisted protocols with conventional walking bleaching in terms of bleaching efficacy. Seventy-two human incisor teeth underwent regenerative treatment. A triple antibiotic paste containing minocycline, ciprofloxacin, and metronidazole was used as an intracanal medicament. A human blood clot was applied as a scaffold and capped by a hydraulic calcium silicate-based cement. Ten weeks after the RET procedure, a four-session bleaching course started. Teeth were assigned to four groups: (1) 35% hydrogen peroxide gel, (2) 35% hydrogen peroxide gel + Nd: YAG laser, (3) 35% hydrogen peroxide gel + 980 nm diode laser, and (4) 35% hydrogen peroxide gel + 810 nm diode laser. The color changes (ΔE) were measured before and after bleaching sessions. The data were analyzed using Kruskal-Wallis nonparametric test. The statistical significance level was set at 0.05. Significant discoloration, exceeding the perceptibility threshold (ΔE > 3.7) was observed in all of the samples ten weeks after RET. There was no significant difference between groups in terms of RET-induced discoloration values (p > 0.05). Bleaching either by using 35% hydrogen peroxide or 35% hydrogen peroxide activated by different lasers used in this study resulted in significant tooth whitening (p < 0.05). There was no statistically significant difference among the groups in terms of bleaching efficacy (p > 0.05). Internal bleaching by using 35% hydrogen peroxide is as effective as laser-assisted protocols for correction of crown discoloration in teeth that have undergone RET.

Free Skin Grafting to Reconstruct Donor Sites after Radial Forearm Flap Harvesting: A Prospective Study with Platelet-Rich Fibrin (PRF)

Reconstruction of the donor site after radial forearm flap harvesting is a common procedure in maxillofacial plastic surgery. It is normally carried out with split-thickness or full-thickness free skin grafts. Unfortunately, free skin graft transplantation faces wound healing impairments such as necrosis, (partial) graft loss, or tendon exposure. Several studies have investigated methods to reduce these impairments and demonstrated improvements if the wound bed is optimised, for example, through negative-pressure wound therapy or vacuum-assisted closure. However, these methods are device-dependent, expansive, and time-consuming. Therefore, the application of platelet-rich fibrin (PRF) to the wound bed could be a simple, cost-effective, and device-independent method to optimise wound-bed conditions instead. In this study, PRF membranes were applied between the wound bed and skin graft. Results of this study indicate improvements in the PRF versus non-PRF group (93.44% versus 86.96% graft survival, p = 0.0292). PRF applied to the wound bed increases graft survival and reduces impairments. A possible explanation for this is the release of growth factors, which stimulate angiogenesis and fibroblast migration. Furthermore, the solid PRF membranes act as a mechanical barrier ("lubrication" layer) to protect the skin graft from tendon motion. The results of this study support the application of PRF in donor-site reconstruction with free skin grafts.

Changes in Migratory Speed Rate of Human Dental Pulp Stromal Cells Cultured in Advanced Platelet-Rich Fibrin

OBJECTIVE

 Migratory speed rate evaluation of human dental pulp stromal cells (hDP-SCs) is one of the important steps in dental pulp regeneration. Therefore, the aim of the study is to analyze various concentrations of advanced platelet-rich fibrin (A-PRF) culture media toward hDP-SCs' migratory speed rate evaluations.

MATERIALS AND METHODS

 The hDP-SCs were divided into four groups: control: hDP-SCs in Dulbecco's modified Eagle medium + 10% fetal bovine serum group; hDP-SCs in 1% A-PRF group; hDP-SCs in 5% A-PRF group; and hDP-SCs in 10% A-PRF group, which were planted in 24-well (5 × 10⁴ cell/well). The migratory speed rate of all groups was measured by using cell migration assay (scratch wound assay) after 24 hours. Cell characteristics were evaluated under microscope (Inverted microscope, Zeiss, Observer Z1, UK) that can be read through image-J interpretation. This image J represented the measurement of migratory speed rate (nm/h) data. Statistical analysis was conducted using one-way analysis of variance and post hoc Tamhane's test (p < 0.05) (IBM SPSS Statistics Software, version 22.0).

RESULTS

 There was a statistically significant difference in the migratory speed rates of hDP-SCs among various concentration groups of A-PRF (1, 5, and 10%) compared with the control group.

CONCLUSION

The increase in the migratory speed rate of hDP-SCs was highest in 10% A-PRF group.

Regenerative Endodontic Procedures for the Treatment of Necrotic Mature Teeth: A Preliminary Randomised Clinical Trial

AIM

This preliminary randomised, prospective, controlled trial aimed to compare the clinical and radiographic outcomes of two regenerative endodontic procedures (REPs), revitalisation and a platelet-rich fibrin (PRF)-based technique, in the treatment of mature permanent teeth with necrotic pulps.

METHODOLOGY

The trial has been reported according to the Preferred Reporting Items for Randomised Trials in Endodontics 2020 guidelines. The study protocol was registered at the clinical trial registry (ClinicalTrials.gov) with identifier number NCT04158232. Twenty patients with mature necrotic anterior teeth with large periapical lesions were randomly allocated into two groups (n=10): group I, treated with revitalisation with the blood clot (BC) technique, and Group II, treated with a PRF-based technique. The follow-up was for 12 months. Periradicular healing was assessed using standardised radiographs taken at baseline, and at 6 and 12 months after treatment. An electric pulp tester was used to assess whether pulp sensibility had been regained during the follow-up period. Statistical analysis was conducted using Mann-Whitney test and Wilcoxon test for non-parametric data. For parametric data, repeated measures analysis of variance was used. The significance level was set at P≤0.05.

RESULTS

There was a significant increase in periradicular healing in both groups at 6 and 12 months, compared to that at baseline, with no significant difference between the studied groups after 12 months (P=0.143). There was a significant difference between the tooth sensibility readings at baseline, 6-month, and 12-month follow-up timepoints (P<0.001).

CONCLUSIONS

The findings of this preliminary trial indicate the potential for using REPs, such as revitalisation or PRF-based techniques, as treatment options for mature teeth with necrotic pulps. A higher level of evidence obtained through adequately powered clinical trials and longer follow-up periods are required to conclusively validate the different outcomes of REPs.

Comparative evaluation of bioglass nanofiber, dexamethasone-coated bioglass nanofiber, and platelet-rich fibrin, as scaffolds in regenerative endodontic treatment of immature necrotic teeth: A randomized controlled trial

Aim

The aim of this study was to evaluate and compare the regenerative endodontic potential of dexamethasone-coated bioglass nanofiber (Dex-BGnf), bioglass nanofiber (BGnf), and platelet-rich fibrin (PRF) for inducing regeneration in necrotic immature permanent teeth.

Materials and Methods

A total of 36 (n = 12) immature necrotic teeth with or without evidence of periapical lesion were included in the study. Patients were randomly allocated into three groups, based on the scaffolds used: Group I (PRF), II (BGnf), and III (Dex-BGnf). The clinical (electric pulp test) and radiographic evaluations (percentage increase in apical diameter, root length, root dentin thickness, and periapical healing) were compared at 6 and 12 months after the procedure with baseline records.

Statistical Analysis

One-way ANOVA, post hoc Tukey analysis, and Kruskal-Wallis test were used for evaluating the data. A 6- and 12-month improvement analysis was done using paired t-test and Friedman test.

Results

Clinically, all the 36 teeth were asymptomatic, but none gave a positive response to Electric Pulp Test (EPT) in time interval of 12 months. Dex-BGnf showed a statistically significant improvement in terms of increase in root length (P = 0.020) and root dentinal thickness (P = 0.001) when compared to PRF after 12 months.

Conclusion

The study has shown that Dex-BGnf yielded significantly better results than PRF for inducing apexogenesis in necrotic immature teeth.

Platelet-Rich Fibrin Used in Regenerative Endodontics and Dentistry: Current Uses, Limitations, and Future Recommendations for Application

Regenerative endodontics has introduced numerous procedures such as pulp implantation, revascularization, and postnatal stem cell therapy. Revascularization has been successfully implemented clinically nowadays, thus providing dentists with outrageous results. Platelet-rich fibrin (PRF) used either alone or along with bone graft promotes bone growth and vascularization. This matrix promotes migration, cell attachment, and proliferation of osteoblast that leads to bone formation. PRF consists of a packed fibrin complex consisting of leukocytes, cytokines, and glycoproteins such as thrombospondin. The usage of PRF has reported high success rates in surgical cases such as sinus lift procedures, healing of extraction sockets, and management of periapical abscesses. Compared to platelet-rich plasma, PRF is more economical, easy to prepare, and feasible to use in daily clinical practices. Revascularization compromised the induction of a blood clot into the root canal space, which emerged as a clinical triumph. This further led to platelet concentrates as an autologous scaffold on which revascularization could occur. The applications of PRF in regenerative endodontics are numerous, such as an agent for repairing iatrogenic perforation of the pulpal floor and for the revascularization of immature permanent teeth with necrotic pulps. It acts as a matrix for tissue ingrowth. Evidence of progressive thickening of dentinal walls, root lengthening, regression in the periapical lesion, and apical closure was reported. Further studies are needed to clarify the precise mechanism of action of PRF for dental pulp regeneration both in vitro and in vivo. The current review aims at the present uses of PRF in regenerative endodontics dentistry and its application with future recommendations and limitations.

SB, Babu G, Vijayan V. Clinical Application of Platelet-Rich Fibrin in Pediatric Dentistry

Platelet-rich fibrin (PRF) is a fibrin matrix in which platelet cytokines, growth factors, and cells are trapped and may be released after a certain time and that can serve as a resorbable membrane. It can be obtained from blood with the help of a simple process. PRF is basically a concentrate of growth factors that promote wound healing and regeneration, which is used in various disciplines of dentistry to repair various lesions and regenerate dental and oral tissues. Although the use of PRF is well-documented, its use in pediatric dentistry remains unexplored, due to its restrictions and on account of the fact that it is a blood-derived product. PRF has been used globally to enhance tissue healing. This article provides an insight into the use of PRF in pediatric dentistry, its benefits, limitations, and recommendations.

PRP and PRF-Subgroups and Divisions When Used in Dentistry

Blood derivates, such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), are autogenous sources of many growth factors that are involved in the healing and regeneration of tissues, and for this reason, are used in dentistry treatments. This fact also contributes to the growing interest in these biomaterials in regenerative personalized medicine. The multitude of platelet-rich forms creates many possibilities for their use. This semi-systematic review describes and compares the methods of obtaining properties and potential uses of these materials in personalized treatments.

Regenerative Endodontic Procedure of Immature Permanent Teeth with Leukocyte and Platelet-rich Fibrin: A Multicenter Controlled Clinical Trial

INTRODUCTION

The aim of this nonrandomized, multicenter controlled clinical trial was to evaluate the impact of leukocyte-platelet-rich fibrin (LPRF) on regenerative endodontic procedures (REPs) of immature permanent teeth in terms of periapical bone healing (PBH) and further root development (RD).

METHODS

Healthy patients between 6-25 years with an inflamed or necrotic immature permanent tooth were included and divided between the test (= REP + LPRF) and control (= REP-LPRF) group depending on their compliance and the clinical setting (university hospital or private practice). After receiving REP ± LPRF, the patients were recalled after 3, 6, 12, 24, and 36 months. At each recall session, the teeth were clinically and radiographically (by means of a periapical radiograph [PR]) evaluated. A cone-beam computed tomographic (CBCT) imaging was taken preoperatively and 2 and 3 years postoperatively. PBH and RD were quantitatively and qualitatively assessed.

RESULTS

Twenty-nine teeth with a necrotic pulp were included, from which 23 (9 test and 14 control) were analyzed. Three teeth in the test group had a flare-up reaction in the first year after REP. Except for 2 no shows, all the analyzed teeth survived up to 3 years after REP, and, in case of failure, apexification preserved them. Complete PBH was obtained in 91.3% and 87% of the cases based on PR qualitative and quantitative evaluation, respectively, with no significant difference between the groups with respect to the baseline. The PR quantitative change in RD at the last recall session with respect to the baseline was not significant (all P values > .05) in both groups. The qualitative assessment of the type of REP root healing was nonuniform. In the test group, 55.6% of the teeth presented no RD and no apical closure. Only 50% of the 14 teeth assessed with CBCT imaging presented complete PBH. Regarding volumetric measurements on RD 3 years after REP for the change with respect to the baseline in root hard tissue volume, mean root hard tissue thickness, and apical area, the control group performed significantly in favor of RD than the test group (P = .03, .003, and 0.05 respectively). For the volumetric change 3 years after REP with respect to the baseline in root length and maximum root hard tissue thickness, no significant difference (P = .72 and .4, respectively) was found between the groups. The correlation between the PR and CBCT variables assessing RD was weak (root lengthening) to very weak (root thickening).

CONCLUSIONS

REP-LPRF seems to be a viable treatment option to obtain PBH and aid further RD of necrotic immature permanent teeth. Caution is needed when evaluating REP with PR.

Prognosis of Regenerative Endodontic Procedures in Mature Teeth: A Systematic Review and Meta-Analysis of Clinical and Radiographic Parameters

This work aimed to investigate the use of Regenerative Endodontic Procedures (REP) on the treatment of pulp necrosis in mature teeth through systematic review and meta-analysis of evidence on clinical and radiographic parameters before and after REP. A search was performed in different databases on 9 September 2020, including seven clinical studies and randomized controlled trials (RCT). The methodological quality was assessed using Revised Cochrane risk-of-bias (RoB 2) and Before-and-After tools. Meta-analyses were performed to evaluate the success incidences regarding the reduction of periapical lesion and recovery of sensitivity. The certainty of the evidence was assessed using GRADE. Meta-analysis showed a high overall success of 0.95 (0.92, 0.98) I² = 6%, with high periapical lesion reduction at 12 months (0.93 (0.86, 0.96) I² = 37%) and by the end of follow-up (0.91 (0.83, 0.96) I² = 13%). Lower incidences of positive sensitivity response were identified for the electrical (0.58 (0.46, 0.70) I² = 51%) and cold tests (0.70 (0.54, 0.84) I² = 68%). The calculated levels of REP success were similar to those reported for immature teeth. With a very low certainty of evidence, the meta-analysis showed a high incidence of REP’s success for mature teeth with necrotic pulp evidenced by periapical lesion reduction and moderate positive responses to sensitivity tests.

Prospective cohort study of regenerative potential of non vital immature permanent maxillary central incisors using platelet rich fibrin scaffold

Regenerative endodontic procedures have gained momentum as a treatment modality of young immature permanent teeth. Literature reports reveal that platelet-rich fibrin (PRF) stimulates growth factors and induces regeneration. This study was undertaken to assess the regenerative potential of non-vital immature permanent maxillary central incisors using PRF with a follow-up for 2 yrs. 19 patients in the age group of 9–25 yrs with immature, non-vital permanent maxillary central incisors (n = 23) with/without signs and/or symptoms of periapical pathosis and open apex were included in this study. In the first appointment, access opening, canal disinfection and triple antibiotic paste placement were done. In the subsequent visit, PRF was prepared and placed inside the canal. Access was sealed with Mineral trioxide aggregate plug and composite. The patient was reviewed up to 24 mths. The mean difference was statistically analyzed using Friedman test followed by Dunn post hoc test and adjusted by Bonferroni correction (p < 0.05). As per AAE guidelines, the primary and secondary goals were achieved. A significant (p < 0.001) gradual increase in the root length, thickness of dentinal walls and decrease in apical diameter were observed. Within the limitations of this study, PRF placement was clinically and radiographically effective in inducing regeneration of non-vital immature permanent teeth.

The effects and potential applications of concentrated growth factor in dentin-pulp complex regeneration

The dentin-pulp complex is essential for the long-term integrity and viability of teeth but it is susceptible to damage caused by external factors. Because traditional approaches for preserving the dentin-pulp complex have various limitations, there is a need for novel methods for dentin-pulp complex reconstruction. The development of stem cell-based tissue engineering has given rise to the possibility of combining dental stem cells with a tissue-reparative microenvironment to promote dentin-pulp complex regeneration. Concentrated growth factor, a platelet concentrate, is a promising scaffold for the treatment of dentin-pulp complex disorders. Given its characteristics of autogenesis, convenience, usability, and biodegradability, concentrated growth factor has gained popularity in medical and dental fields for repairing bone defects and promoting soft-tissue healing. Numerous in vitro studies have demonstrated that concentrated growth factor can promote the proliferation and migration of dental stem cells. Here, we review the current state of knowledge on the effects of concentrated growth factor on stem cells and its potential applications in dentin-pulp complex regeneration.

Nonsurgical Management of Strip Perforation Using Platelet-Rich Fibrin and MTA by Matrix Concept - A Case Report with One Year Follow-up

Iatrogenic errors happen especially during endodontic treatment even with the experienced clinicians. It is impossible to predict the occurrence of an event. Although many of them can be corrected and managed successfully, few conditions might have the worst prognosis leading to uneventful extraction. The present case report highlights a 1-year follow-up of managed strip perforation in mesial canals of mandibular first molar, nonsurgically using MTA obturation. The present challenging case gives an insight on the importance of regenerative capacity and osteogenic potentiality of bioactive materials, when appropriate tissue engineering concepts are applied.

Long-term follow-up of traumatized immature necrotic permanent teeth treated with regenerative endodontic protocol using platelet-rich fibrin: A prospective case series

The purpose of this prospective case series was to report the long-term clinical and radiographic outcomes of regenerative endodontic procedures (REP) using platelet-rich fibrin (PRF), in traumatized immature permanent teeth with necrotic pulps. Six immature necrotic permanent maxillary central incisors from six patients were treated with REP supplemented with PRF. Patients were recalled at 6, 12, 18, 24, 36, 48, and 60 months. Radiographic changes in the radiographic root area (RRA), apical diameter, root thickness, and root length were quantified. Clinically, tooth survival in terms of tooth retention in the arch and absence of any sign and symptoms of endodontic pathology were noted. All the teeth survived and met the clinical criteria for success throughout the follow-up period. Follow-up radiographs at 5 years revealed complete resolution of the periapical lesions in all patients and the average apical diameter decrease was 30.96%. An average increase of 13.18% for root length, 40.20% for root thickness, and 26.35% for RRA were noted.

Platelet-Rich Fibrin Enhances Surgical Wound Healing in Total Laryngectomy

Autologous growth factor (AGF) is a cytokine that has gained medical research interest because it helps improve and accelerate the wound healing process. Platelet-rich fibrin (PRF) is the latest generation of platelet concentrate that can be obtained through a simple procedure known as AGF referencing. One of the most common complications of total laryngectomy (TL) is pharyngocutaneous fistula. To prevent this complication, health care providers must closely monitor the postoperative wound healing process.This study aimed to investigate the effectiveness of PRF application in enhancing wound healing after TL. A randomized controlled trial was conducted in the Department of Otorhinolaryngology - Head and Neck Surgery, Faculty of Medicine, Dr. Cipto Mangunkusumo Hospital Universitas Indonesia, Jakarta, Indonesia, from June 2019 to December 2019. We included 20 patients who underwent TL for laryngeal squamous cell carcinoma. They were divided into two groups (10 patients who received applied autologous PRF around the esophageal stoma during TL and another 10 patients as the control). These patients were observed for 2 weeks postoperatively. In the bivariate analysis performed using the chi-square test, the pain threshold and edema of postoperative wounds in the PRF-treated group demonstrated significant differences compared with those in the control group. PRF application in TL enhanced the postoperative wound healing process, especially with regard to edema and pain.

Evidence-Based Clinical Efficacy of Leukocyte and Platelet-Rich Fibrin in Maxillary Sinus Floor Lift, Graft and Surgical Augmentation Procedures

Bone augmentation techniques have increasingly been indicated for re-creating adequate bone height and volume suitable for dental implant sites. This is particularly applicable in the severely atrophic posterior maxilla where sinus perforation (ruptured Schneiderian membrane) is a very common complication and sinus floor elevation or lift is frequently considered a standard procedure. The augmentation of the maxillary sinus can be performed with or without grafting biomaterials. Herein, numerous biomaterials and bone substitutes have been proposed, primarily to sustain the lifted space. In addition, cytokines and growth factors have been used to stimulate angiogenesis, enhance bone formation as well as improve healing and recovery period, either as the sole filling material or in combination with bone substitute materials. Within such, is the family of autologous blood extracts, so-called platelet concentrates, which are simply the "product" resulting from the simple centrifugation of collected whole blood samples of the patient, immediately pre-surgery. Platelet-Rich Fibrin (PRF), a sub-family of platelet concentrates, is a three-dimensional (3-D) autogenous biomaterial obtained, without including anti-coagulants, bovine thrombin, additives, or any gelifying agents during the centrifugation process. Today, it is safe to say that, in implant dentistry and oral and maxillofacial surgery, PRFs (particularly, the pure platelet-rich fibrin or P-PRF and leukocyte and platelet-rich fibrin or L-PRF sub-classes) are receiving the most attention, essentially due to their simplicity, rapidness, user-friendliness/malleability, and cost-effectiveness. Whether used as the sole "bioactive" filling/additive material or combined with bone substitutes, the revolutionary second-generation PRFs have been very often associated with promising clinical results. Hence, this review aims to provide a 10-years update on the clinical effectiveness of L-PRF when applied/used as the "sole" biomaterial in maxillary sinus augmentation procedures. An electronic search using specific keywords for L-PRF and maxillary sinus augmentation was conducted in three main databases (PubMed-MEDLINE database, Google Scholar and Cochrane library) for the period between January 2009-February 2020. The quest yielded a total of 468 articles. Based on the pre-established strict inclusion/exclusion criteria, only seven articles were deemed eligible and included in the analysis. Surprisingly, of the 5 studies which used de-proteinized bovine bone mineral (DBBM) in combination with L-PRF, 60% acclaimed no significant effects and only 40% declared positive effects. Of the two articles which had used allogenous bone graft, 50% declared no significant effects and 50% acclaimed positive effects. Only one study had used L-PRF as the sole grafting material and reported a positive effect. Likewise, positive effects were reported in one other study using L-PRF in combination with a collagen membrane. Due to the heterogeneity of the included studies, this review is limited by the inability to perform a proper systematic meta-analysis. Overall, most of the published studies reported impressive results of L-PRF application as a grafting material (sole or adjuvant) in maxillary sinus augmentation and dental implant restorative procedures. Yet, distinct technical processing for L-PRF preparation was noted. Hence, studies should be approached with caution. Here in, in sinus lift and treatment of Schneider membrane, the formation of mature bone remains inconclusive. More studies are eagerly awaited in order to prove the beneficial or detrimental effects of PRFs, in general and L-PRFs, in specific; especially in their tissue regenerative potential pertaining to the promotion of angiogenesis, enhancing of cell proliferation, stimulation of cell migration and autocrine/paracrine secretion of growth factors, as well as to reach a consensus or a conclusive and distinct determination of the effect of leukocytes (and their inclusion) on inflammation or edema and pain; a call for standardization in PRFs and L-PRFs composition reporting and regimenting the preparation protocols.

Platelet rich fibrin versus ozone gel for periodontal regeneration in induced rats' intrabony three-wall periodontal defects

BACKGROUND

The question of whether platelet rich fibrin and ozone can enhance regeneration of periodontal defect was addressed.

MATERIALS AND METHODS

three-wall periodontal defects were surgically created in 30 rats involving mesial aspect of right mandibular first molar. Rats were randomly assigned into three groups: 1) Group I (Positive control group). 2) Group II (Ozone treated group) and 3) Group III (PRF treated group). Two weeks after surgery, five rats from each group were euthanized and the remaining was euthanized 4 weeks post surgery. The degree of periodontal regeneration was evaluated using light microscope and scanning electron microscope. Histomorphometric measurements and anti-PCNA immunohistochemical counting were statistically analyzed.

RESULTS

group I showed intense inflammatory reaction with mild new bone formation. In group II, partial regeneration was seen with moderate new woven bone formation in 2 weeks period. After 4 weeks, almost complete restoration of periodontium was seen. In group III, after 2 weeks, moderate lamellar bone formation was observed. In 4 weeks period, the periodontal regeneration was almost completed. Histomorphometric analysis showed a significant difference between group I and group II. The difference between group I and group III was significant in 2 weeks and highly significant after 4 weeks. That between group II and group III was nonsignificant in 2 weeks and significant in 4 weeks. Anti-PCNA analysis was nonsignificant between groups.

CONCLUSIONS

both Platelet rich fibrin and ozone can improve histological parameters associated with healing of experimental intrabony periodontal defects in rats with the former being superior.

Evaluation of the regenerative potential of dentin conditioning and naturally derived scaffold for necrotic immature permanent teeth in a dog model

This study evaluated the outcome of partial exposure of dentin matrix to ethylenediaminetetraacetic acid (EDTA) and application of platelet-rich fibrin (PRF) scaffold on regeneration of necrotic immature permanent teeth in a dog model. The present study was carried out on 216 permanent immature roots in nine mongrel dogs aged 6-9 months. Pulp necrosis and periapical pathosis were induced in 180 roots. These roots were divided into five equal groups (36 roots each) according to the treatment protocol: group I: blood clot; group II: 17% EDTA solution and blood clot; group III: PRF; group IV: 17% EDTA solution and PRF; and group V: without treatment (positive control). The negative control group (group VI) represented 36 untouched normal roots for normal maturation. The groups were followed up for 1, 2 and 3 months (subgroups). Maturation of the roots was monitored by radiography and histopathology. All data were statistically analysed. Group IV exhibited the highest increase in root length and thickness, decrease in apical diameter, the highest score of vital tissue infiltration and least inflammatory scores. There was a significant difference regarding the increase in root length and thickness and decrease in apical diameter in all subgroups of the experimental and negative control groups (P ≤ .05). PRF has a better regenerative potential than the blood clot during treatment of immature permanent teeth with necrotic pulp. Inclusion of 17% EDTA solution as a final irrigation enhances the regenerative potential of both PRF and blood clot.

A Comparative Evaluation of Revascularization Done in Traumatized Immature, Necrotic Anterior Teeth with and without Platelet-rich Fibrin: A Case Report

The aim of this paper is to present two methods of revascularization done in traumatized immature, nonvital anterior teeth using platelet-rich fibrin (PRF) and natural blood clot as a scaffold material. This was performed after disinfection of the root canal space using tri-antibacterial paste. In one tooth, PRF prepared from autologous blood was placed in the canal and in the other tooth, natural bleeding was induced to obtain a fresh blood clot. The patient was recalled regularly at 1, 3, 6, 9, and 12 months’ interval for evaluation. After 12 months, on clinical examination, both teeth showed negative response to percussion and palpation tests but positive response to cold and electric pulp tests. On radiographic examination, the tooth treated with PRF exhibited comparatively faster root lengthening, complete closure of the root apex, more thickening of the root dentinal walls, and narrowing of root canal space compared to conventionally revascularized tooth.

How to cite this article: Nagaveni NB, Poornima P, Mathew MG, et al. A Comparative Evaluation of Revascularization Done in Traumatized Immature, Necrotic Anterior Teeth with and without Platelet-rich Fibrin: A Case Report. Int J Clin Pediatr Dent 2020;13(1):98–102.

Synthesis, molecular structure and antioxidant activity of bis [L(μ2-chloro)copper(II)] supported by phenoxy/naphthoxy-imine ligands

A new series of Cu(II) complexes [bis[{(μ₂-chloro)-2-MeO-Ph-CH₂-(N=CH)-2,4-tert-butyl-2-OC₆H₂)}Cu(II)] (Cu1); bis[{(μ₂-chloro)-2-MeS-Ph-CH₂-(N=CH)-2,4-tert-butyl-2-(OC₆H₂)}Cu(II)] (Cu2); bis[{(μ₂-chloro)-2-MeO-Ph-CH₂-(N=CH)-2-(OC₁₀H₆)} Cu(II)] (Cu3); bis[{(μ₂-chloro)-2-MeS-Ph-CH₂-(N=CH)-2-(OC₁₀H₆)}Cu(II)] complex (Cu4); bis[{2-MeS-Ph-CH₂-(N=CH)-2,4-tert-butyl-2-(OC₆H₂)}Cu(II)] (Cu5)] have been synthesized and characterized by elemental analysis, IR, UV-Visible and by X-ray crystallography for Cu1, Cu4 and Cu5. In the solid state, Cu1 features of a chloro-bridged dimer complex with κ² coordination of the monoanionic phenoxy-imine ligand onto the copper center. On the other hand, the molecular structure of Cu4 reveals the naphthoxy-imine ligand with pendant S-group coordinated to the copper atom in tridentate meridional fashion. Treatment of [Cu(OAc)₂·H₂O] with two equiv. of [2-MeS-Ph-CH₂-(N=CH)-2,4-tert-butyl-2-(HOC₆H₂)] led to a monomeric complex Cu5, with the ONS-donor Schiff base acting as a bidentate ligand. The redox behavior was explored by cyclic voltammetry. The reduction/oxidation potential of Cu(II) complexes depends on the structure and conformation of the central atom in the coordination compounds. Antioxidant activities of the complexes, Cu1 - Cu5, were determined by in vitro assays such as 1,1-diphenyl-2-picryl-hydrazyl free radicals (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals (ABTS⁺). The dinuclear compounds Cu1-Cu4, from the concentration of 5 μM, presented a good activity in scavenging DPPH radical. In addition, most of the Cu(II) complexes showed ABTS^.+ radical-scavenging activity. The monomeric complex Cu5 at all concentrations tested showed antioxidant inability. The cytotoxicity of the Cu1 and Cu3 was determined in V79 cell line by reduction of 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay.

Injectable Biomaterials for Dental Tissue Regeneration

Injectable biomaterials scaffolds play a pivotal role for dental tissue regeneration, as such materials are highly applicable in the dental field, particularly when compared to pre-formed scaffolds. The defects in the maxilla-oral area are normally small, confined and sometimes hard to access. This narrative review describes different types of biomaterials for dental tissue regeneration, and also discusses the potential use of nanofibers for dental tissues. Various studies suggest that tissue engineering approaches involving the use of injectable biomaterials have the potential of restoring not only dental tissue function but also their biological purposes.

Role of Platelet-Rich Fibrin (PRF) and Platelet-Rich Plasma (PRP) in Oro-Facial Tissue Regeneration: A Narrative Review

Background and Aim:

Regeneration potential of platelet-rich fibrin (PRF) and platelet-rich plasma (PRP) in oral tissues regeneration has revolutionized the clinical dentistry in recent years. The in vivo and in vitro research on PRP and PRF has opened a new avenue in the dentistry and medicinal care. It is a minimally invasive and cost-effective technique that will raise the bar of clinical dentistry. The results presently documented are overwhelming; the potential to use PRF and PRP in the clinical dentistry have improved dental quality, satisfaction, and clinical outcome. The aim of the review was to recapitulate the regenerative and healing potential of platelet extracts in different disciplines of clinical dentistry.

Materials and Methods:

The attempt was to answer the following question: what are the various clinical oral health applications for PRF and PRP available in the published literature? The dual functions (tissue sealants and drug delivery systems to carry biomolecules and chemotactic growth factors) have helped the practitioners to treat the complicated oral conditions and tissues regeneration. The PRF and plasma has emerged as a powerful therapeutic tool for management of soft and hard tissue healing and regenerative procedures, including implant osseointegration. More research is mandatory to use these platelets concentrate to their full potential in various clinical applications.

Conclusion:

PRF is an emerging therapeutic tool in the management of oral soft and hard tissue healing and regenerative procedures.

Vital Pulp Therapy an Insight Over the Available Literature and Future Expectations

Vital pulp therapy (VPT) defined as “treatment which aims at preserving and maintaining the pulp tissue that has been compromised but not destroyed by extensive dental caries, dental trauma, and restorative procedures or for iatrogenic reasons”, offers some beneficial advantages over the conventional root canal treatment such as protective resistance for mastication forces or to prevent the loss of environmental changes sensation ability, which can lead to unnoticeable progression of caries and later fracture. A wide range of materials are suggested in the literature to be used as pulp capping protective dressing materials that varies from ready-made synthetic materials to biological based scaffolds and composites. The aim of the present review is to provide a full understanding of currently used materials to clinicians in order to help in their decision-making process delivering the best available evidence-based treatments to their patients. An extensive search for recent available data regarding direct pulp capping materials and potential suggestions for future use have been made. Newly developed biological based scaffolds showed promising results in dentine regeneration therefore strengthening the tooth structure and overcoming potential drawbacks of use of currently available recommended materials.

The Effects of Leukocyte-Platelet Rich Fibrin (L-PRF) on Suppression of the Expressions of the Pro-Inflammatory Cytokines, and Proliferation of Schwann Cell, and Neurotrophic Factors

This study evaluates the use of L-PRF as an autologous scaffold in nerve regeneration, and Schwann cells (SCs) proliferation and secretion of neurotrophic factors and its anti-inflammatory effect on SC Porphyromonas Gingivalis-Lipopolysaccharide (PG-LPS)-induced inflammatory responses in vitro. SEM was done to investigate various features of L-PRF. L-PRF-extracts was used to investigate the release of growth factors and treatment of SCs line. ELISA was applied to examine the release of IGF-1. The proliferative effect of L-PRF on SCs was assessed with CCK-8 assay. The effect of L-PRF on the mRNA and protein expression of SC neurotrophic factors were analyzed by RT-qPCR and ELISA. CCK-8 assay and RT-qPCR were used to determine the required concentration and the action time of PG-LPS before the anti-inflammatory effect of L-PRF was determined by measuring the changes in IL-1β, IL-6, and TNF-a with RT-qPCR and ELISA. There are different features in L-PRF. Fourteen days was sufficient to release adequate GF. The mRNA expressions of the pro-inflammatory cytokines were notably raised by PG-LPS in 3-hours treatment. L-PRF can increase SC proliferation, neurotrophic factors secretion, and suppress SC PG-LPS-induced inflammatory responses in vitro. L-PRF has the potential as an autologous biological additive for peripheral nerve regeneration in the event of nerve inflammation and injuries.

Effect of five dental pulp capping agents on cell proliferation, viability, apoptosis and mineralization of human dental pulp cells

The aim of the present study was to investigate the effect of calcium hydroxide [Ca(OH)₂], mineral trioxide aggregate (MTA), iRoot BP, platelet-rich fibrin (PRF) and concentrated growth factors (CGF) on the proliferation, viability, apoptosis and mineralization of human dental pulp cells (HDPCs). HDPCs were treated with Ca(OH)₂, MTA, iRoot BP, PRF and CGF exudates. Cell viability, apoptosis, proliferation, cell cycle and alkaline phosphatase (ALP) activity were evaluated in vitro. PRF significantly increased the cell proliferation as compared with that in the MTA and iRoot BP groups on day 3. The CGF group displayed higher proliferation rates as compared with that in the MTA group on days 3 and 7. The MTA group displayed the highest ALP activity on days 1 and 3, and the CGF group on day 7. Ca(OH)₂ inhibited cell proliferation and the percentages of dead and apoptotic cells were relatively higher in the Ca(OH)₂ group on days 1, 3 and 7 compared with those in the other groups. In conclusion, PRF and CGF may be potential pulp-capping materials for vital pulp therapy. Future in vivo studies are required to confirm this.

Effect of platelet-rich fibrin on cell proliferation, migration, differentiation, inflammation, and osteoclastogenesis: a systematic review of in vitro studies

Objective

To systematically assess the effects of platelet-rich fibrin (PRF) on in vitro cellular behavior.

Methods

A systematic electronic search using MEDLINE database was performed. In vitro studies using PRF were considered and articles published up to June 31, 2018 were screened. Eligible studies were selected based on the use of human PRF.

Results

In total, 1746 titles were identified with the search terms, from these 37 met the inclusion criteria and were chosen for data extraction. In addition, 16 new studies, mainly published in 2019, were also included in the analysis resulting in 53 studies. No meta-analysis could be performed due to the heterogeneity of study designs. Included studies show that PRF enhances proliferation, migration, adhesion, and osteogenic differentiation on a variety of cell types along with cell signaling activation. Furthermore, PRF reduces inflammation, suppresses osteoclastogenesis, and increases the expression of various growth factors in mesenchymal cells.

Summary and conclusions

Despite some notable differences of the studies, the overall findings suggest a positive effect of PRF on cell proliferation, migration, adhesion, differentiation, and inflammation pointing towards a therapeutic potential in regenerative dentistry.

Clinical relevance

PRF serves as a reservoir of bioactive molecules to support wound healing and bone regeneration. Although the cellular mechanisms by which PRF supports the clinical outcomes remain unclear, in vitro research provides possible explanations. This systematic review aims to provide an update of the existing research on how PRF affects basic physiological processes in vitro. The overall findings suggest that PRF induces cell proliferation, migration, adhesion, and differentiation along with possessing anti-inflammatory properties further supporting its therapeutic potential in wound healing and bone regeneration.

Autologous platelet-rich-fibrin-induced revascularization sequelae: Two case reports

BACKGROUND

A key requirement for biomimetic regeneration of tissues is a 3D scaffold. The gold standard scaffold for revascularization is the blood clot, however, an adequate blood clot cannot always be achieved in narrow canals or mature roots. Hereby, we document the effects of platelet-rich fibrin (PRF) for the regenerative endodontic treatment (RET) of two immature permanent teeth with necrotic pulps for up to 48 mo.

CASES SUMMARY

The first patient was a 22-year-old female with history of trauma in tooth #9 with a sinus tract and a large periapical lesion. The second was a 9-year-old male presenting with a badly decayed tooth #14. Both cases were treated with RET and PRF prepared from the patients’ blood. PRF and its extract were used as a scaffold for RET. Patients were followed-up to 9 and 48 mo (4 years), respectively. Both patients, were asymptomatic after treatment. At the 9-mo-follow-up of case #1, there was radiographic evidence of periapical bone healing, however, the root apex was still open. In case #2, the roots exhibited apical closure and normal periapical bone architecture at 12-mo follow-up, while no root lengthening was observed. After 48 mo, case #2 showed extensive intracanal calcification in all root canals that complicated conventional root canal treatment.

CONCLUSION

RET with PRF and its extract could be used in revascularization of immature permanent teeth. However, proper case selection to comply with long-term follow-up is necessary and adverse events such as calcification and canal obliteration should be planned for.

Polymeric scaffolds for dental pulp tissue engineering: A review

OBJECTIVES

The purpose of this review is to describe recent developments in pulp tissue engineering using scaffolds and/or stem cells. It is crucial to understand how this approach can revitalize damaged dentin-pulp tissue. Widespread scaffold materials, both natural and synthetic, and their fabrication methods, and stem-progenitor cells with the potential of pulp regeneration will be discussed.

DATA AND SOURCES

A review of literature was conducted through online databases, including MEDLINE by using the PubMed search engine, Scopus, and the Cochrane Library.

STUDY SELECTION

Studies were selected based on relevance, with a preference given to recent research, particularly from the past decade.

CONCLUSIONS

The use of biomaterial scaffolds and stem cells can be safe and potent for the regeneration of pulp tissue and re-establishment of tooth vitality. Natural and synthetic polymers have distinct advantages and limitations and in vitro and in vivo testing have produced positive results for cell attachment, proliferation, and angiogenesis. The type of biomaterial used for scaffold fabrication also facilitates stem cell differentiation into odontoblasts and the resulting biochemistry of tissue repair for each polymer and cell type was discussed. Multiple methods of scaffold design exist for pulp tissue engineering, which demonstrates the variability in tissue engineering applications in endodontics. This review explains the potential of evidence-based tissue engineering strategies and outcomes in pulp regeneration.

Multifunctional Triple-Layered Composite Scaffolds Combining Platelet-Rich Fibrin Promote Bone Regeneration

There has been substantial progress made in the development of bone regeneration materials, driven by the deficiencies that exist in current clinical products, such as finite sources, donor site complications, and potential for disease transmission. To overcome these shortcomings, multifunctional scaffolds should be developed to integrate the relationship among osteoinduction, osteoconduction, and osseointegration. In this study, we fabricated polycaprolactone/gelatin (PG) nanofiber films by electrospinning, to act as barriers against connective tissue migration into bone defect sites; chitosan/poly (γ-glutamic acid)/hydroxyapatite (CPH) hydrogels were formed by electrostatic interaction and lyophilization, to exert osteoconduction; and platelet-rich fibrin (PRF) was extracted from rat abdominal aorta and combined with composite scaffolds, to promote bone induction through the release of growth factors. Hydrogels were immersed in simulated body fluid (SBF) for 1 month to investigate mineralization in vitro. Cytocompatibility, cell barrier effect, and osteogenic differentiation were also explored in vitro. The ability to effectively regenerate bone was analyzed by implantation of triple-layered composite scaffolds into rat calvarial defects in vivo. Size-matched hydrogel filled the defect site, and then, fresh PRF was applied to the hydrogel surface. Finally, P2G3 nanofiber films were applied and attached to the surrounding soft tissue. In short, we fabricated multifunctional triple-layered scaffolds by combining the advantages of osteoinduction, osteoconduction, and osseointegration, which could give full play to the role of PRF in bone regeneration and provide new and pragmatic concepts for bone tissue regeneration in clinical applications.

Effect of autogenous growth factors released from platelet concentrates on the osteogenic differentiation of periodontal ligament fibroblasts: a comparative study

Background

Platelet concentrates have been used in tissue regeneration. The purpose of this study was to examine effects of growth factors released from leukocyte- and platelet-rich fibrin (L-PRF) and concentrated growth factor (CGF) on the osteogenic differentiation of periodontal ligament fibroblasts (PDLFs).

Methods

Leukocyte- and platelet-rich fibrins, CGFs and PDLFs were obtained from New Zealand rabbits. The release of basic fibroblast growth factor (bFGF), bone morphogenetic protein 2 (BMP-2) and transforming growth factor β1 (TGF-β1) from L-PRFs and CGFs was measured at 5 h and 1, 3, 5, 7 days, using the enzyme linked immunosorbent assay. The PDLFs were treated with exudates of L-PRF or CGF. After the treatment, cell counting kit-8 assay was performed at day 1, 3, 5 and 7. Alkaline phosphatase (ALP) assay and Western blotting were applied at day 7. Three blocking antibodies were used to neutralize the proteins of bFGF, BMP-2 and TGF-β1.

Results

Leukocyte- and platelet-rich fibrin and CGF showed different growth factor release pattern, but similar accumulated concentration of these growth factors. PDLFs proliferation was significantly promoted by both L-PRF and CGF at day 1, 3 and 7, and CGF group was superior to L-PRF group at day 1 and 3. Both L-PRF and CGF significantly enhanced PDLFs ALP activity and protein expression of osteogenic markers. The osteopontin level was higher in CGF group than in L-PRF group, but no significant differences were found between two groups for ALP activity. Three blocking antibodies significantly downregulated both L-PRF and CGF induced osteogenic markers expression.

Conclusion

Both CGF and L-PRF can promote the proliferation and osteogenic differentiation of PDLFs. The bFGF, BMP-2 and TGF-β1 are involved in both L-PRF and CGF induced osteogenic differentiation of PDLFs.