RESUMO
Bone tissue regeneration strategies have incorporated the use of natural polymers, such as hydroxyapatite (nHA), chitosan (CH), gelatin (GEL), or alginate (ALG). Additionally, platelet concentrates, such as platelet-rich fibrin (PRF) have been suggested to improve scaffold biocompatibility. This study aimed to develop scaffolds composed of nHA, GEL, and CH, with or without ALG and lyophilized PRF, to evaluate the scaffold's properties, growth factor release, and dental pulp stem cells (DPSC), and osteoblast (OB) derived from DPSC viability. Four scaffold variations were synthesized and lyophilized. Then, degradation, swelling profiles, and morphological analysis were performed. Furthermore, PDGF-BB and FGF-B growth factors release were quantified by ELISA, and cytotoxicity and cell viability were evaluated. The swelling and degradation profiles were similar in all scaffolds, with pore sizes ranging between 100 and 250 µm. FGF-B and PDGF-BB release was evidenced after 24 h of scaffold immersion in cell culture medium. DPSC and OB-DPSC viability was notably increased in PRF-supplemented scaffolds. The nHA-CH-GEL-PRF scaffold demonstrated optimal physical-biological characteristics for stimulating DPSC and OB-DPSC cell viability. These results suggest lyophilized PRF improves scaffold biocompatibility for bone tissue regeneration purposes.
Assuntos
Alginatos , Sobrevivência Celular , Quitosana , Polpa Dentária , Durapatita , Gelatina , Osteoblastos , Fibrina Rica em Plaquetas , Células-Tronco , Alicerces Teciduais , Humanos , Polpa Dentária/citologia , Quitosana/química , Quitosana/farmacologia , Gelatina/química , Fibrina Rica em Plaquetas/química , Fibrina Rica em Plaquetas/metabolismo , Alicerces Teciduais/química , Células-Tronco/efeitos dos fármacos , Células-Tronco/citologia , Células-Tronco/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Durapatita/química , Durapatita/farmacologia , Alginatos/química , Alginatos/farmacologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/citologia , Adesão Celular/efeitos dos fármacos , Engenharia Tecidual/métodos , Células CultivadasRESUMO
ABSTRACT Objective: The aim of this study is to determine the effect of Advanced Platelet-Rich Fibrin on bone density and implant stability in immediately loaded- implant-assisted mandibular overdentures (Split-mouth study). Material and Methods: Ten completely edentulous patients received two implants in the mandibular canine region and locator attachments were used to retain immediately loaded- implant mandibular overdentures. Each patient served in two Groups, one Group for each side. One side of the mandible received an implant with topical application of Advanced Platelet-Rich Fibrin in the implant osteotomy site (Group I) and the other site received an implant without application of Advanced platelet-rich fibrin (Group II). Each patient was examined clinically for implant stability using Osstell Mentor device and radiographically by ultra-low dose CT scan to measure bone density around the implant at baseline, three, six months, and one year. Results: There were no statistically significant differences (P>.05) in bone density and implant stability among the studied Groups during one year follow-up period. Conclusion : Advanced Platelet-Rich Fibrin has no effect on bone density and implant stability in immediately loaded implant-assisted mandibular overdenture.(AU)
RESUMO Objetivo: O objetivo deste estudo é determinar o efeito da Fibrina Rica em Plaquetas Avançada na densidade óssea e estabilidade dos implantes em Overdentures mandibulares com carga imediata (estudo de boca dividida). Material e Métodos: Dez pacientes edêntulos foram submetidos à instalação de dois implantes mandibulares na região dos caninos e pilares locator foram utilizados como sistema de retenção para as overdentures mandibulares com carga imediata. Cada paciente participou nos dois grupos, sendo um grupo para cada lado. Um lado da mandíbula recebeu implante com aplicação tópica de Fibrina Rica em Plaquetas Avançada no local do sítio cirúrgico do implante (Grupo I) e o outro local recebeu implante sem aplicação de Fibrina Rica em Plaquetas Avançada (Grupo II). Cada paciente foi examinado clinicamente quanto à estabilidade do implante usando o dispositivo Osstell Mentor e radiograficamente por tomografia computadorizada de ultrabaixa dose para medir a densidade óssea ao redor do implante no início do estudo, três, seis meses e um ano. Resultados: Não houve diferenças estatisticamente significativas (P>0,05) na densidade óssea e na estabilidade do implante entre os grupos estudados durante o período de acompanhamento de um ano. Conclusão: A Fibrina Rica em Plaquetas Avançada não tem efeito na densidade óssea e na estabilidade de implantes em Overdentures mandibulares com carga imediata (AU)
Assuntos
Humanos , Pessoa de Meia-Idade , Densidade Óssea/efeitos dos fármacos , Revestimento de Dentadura , Carga Imediata em Implante Dentário , Osteotomia Mandibular , Fibrina Rica em Plaquetas/química , Radiografia , Método Duplo-Cego , Dente Canino/cirurgia , Mandíbula/diagnóstico por imagemRESUMO
This study evaluated the impact of rotor angle and time of storage after centrifugation on the in vitro biological properties of platelet-rich fibrin (PRF) membranes. Blood samples (n = 9) were processed with a vertical fixed-angle (V) or a swing-out horizontal (H) centrifuge, with 20-60 min of sample storage after centrifugation. Leukocytes, platelets, and red blood cells were counted, and fibrin architecture was observed by scanning electron microscopy (SEM). The release of FGF2, PDGFbb, VEGF, IL-6, and IL-1ß was measured after incubation on culture media for 7-21 days. Cell content was equivalent in all experimental groups (p > .05). The fibrin matrix was similar for fixed-angle and horizontal centrifugation. Horizontal centrifugation induced a twofold increase in PDGF and 1.7× increase on FGF release as compared to V samples, while IL-1ß was significantly reduced (p < .05). No significant difference was observed on the release of growth factors and cytokines at different times after centrifugation (p < .05). These data suggest that both angles of centrifugation produce PRF membranes with similar structure and cellularity, but horizontal centrifugation induces a higher release of growth factors. Higher times of storage after centrifugation did not impact on cell content and the release of growth factors.
Assuntos
Centrifugação/instrumentação , Centrifugação/métodos , Fibrina Rica em Plaquetas/química , Adulto , Plaquetas/química , Citocinas/química , Eritrócitos , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/química , Leucócitos/química , Masculino , Pessoa de Meia-IdadeRESUMO
This study analyzed the architecture of Platelet-Rich Fibrin (PRF) clots and assessed their elemental composition in order to provide new insight into this biomaterial. Five surplus PRF clots (2,700 RPM, 12â¯min.) donated by patients (63.6⯱â¯12.3 years old) were prepared for use in dental clinical procedures. The internal three-dimensional morphology of the red zones and the thirds of the yellow zones of the clots were analyzed by Variable Pressure Scanning Electron Microscope (VPSEM) after sample preparation by two methods: 1. Fixation (2.5% gluataraldehyde); and 2. Fixation with subsequent partial removal of extracellular elements (8â¯N, HCl). Semi-quantitative elemental analysis was performed by energy-dispersive X-ray spectrometry (EDX). VPSEM analysis showed erythrocytes in both the red zone and the yellow zone, which consisted mainly of fibrin. Removal of extracellular elements enriched the morphology of both zones; the organization of the fibrin was observed to differ in the thirds of the yellow zone, with increasing density and organization to distal. The elements that compose organic substances (C-Carbon, N-Nitrogen, O-Oxygen, Na-Sodium and P-Phosphorus) and halogens (Cl-Chloride and S-Sulfur) were detected; the highest concentrations were of C, followed by O (pâ¯<â¯0.05), in the proximal region of the fibrin. The results of the present study suggest organization of fibrin in the PRF clot, and also reveal the distribution of the elements present in the different regions of the clot. Improved understanding of these characteristics may favor the use of this biomaterial by increasing its efficiency and functionality.
Assuntos
Coagulação Sanguínea , Elementos Químicos , Fibrina Rica em Plaquetas/química , Espaço Extracelular/química , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Espectrometria por Raios XRESUMO
OBJECTIVES: The aim of this study was to describe the histological and clinical outcome of "dentin block" (a mixture of autologous particulate dentin, leukocyte- and platelet-rich fibrin (L-PRF), and liquid fibrinogen) in alveolar ridge preservation. MATERIAL AND METHODS: Ten extraction sockets were grafted with "dentin block," a mixture of particulate autologous dentin with chopped leukocyte-platelet-rich fibrin (L-PRF) membranes at a 1:1 ratio, and liquid fibrinogen as a binder. Two grafted sites were followed at 4 and 5 months, and 6 sites at 6 months. Biopsies were taken from the core of the grafted site for histologic and histo-morphometric analysis. RESULTS: All patients completed the study without any adverse event. The vertical and horizontal dimensions of the alveolar ridge were preserved or even increased after 4, 5, or 6 months and remained stable after 6 months of the implant placement. The histological examination revealed a median relative percentage of bone, dentin, and connective tissue of 57.0, 0.9, and 39.3%, respectively. A comparison of samples at different time points (4, 5, and 6 months) showed a progressive increase in the proportion of bone with a decrease in the proportion of dentin. The bone was compact with normal osteocytes and moderate osteoblastic activity. In 4 out of 10 samples, no dentin was observed; in the other samples, it represented 1-5% (with geometric fragments). CONCLUSIONS: Dentin block showed to be a suitable bone substitute in an alveolar ridges preservation model. CLINICAL RELEVANCE: The promising results of dentin block as a bone substitute in alveolar ridge preservation could have an important clinical impact considering this biomaterial brings together the regenerative potential of three autologous products with excellent biological and clinical behavior, low risk of adverse effects, and feasible acquisition.
Assuntos
Aumento do Rebordo Alveolar , Substitutos Ósseos/uso terapêutico , Dentina/química , Fibrinogênio/química , Fibrina Rica em Plaquetas/química , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Projetos Piloto , Extração Dentária , Alvéolo DentalRESUMO
OBJECTIVES: The aim of the present study was to evaluate the blood cell content, morphological aspects, gene expression of type I collagen, and release of growth factors on an injectable platelet rich fibrin (i-PRF). MATERIALS AND METHODS: Blood samples were collected from 15 volunteers to prepare i-PRF samples. Peripheral blood was used as a control group. Blood clot and i-PRF samples were cultured for 10 days. The supernatant of the samples was collected for ELISA immunoassay quantification of PDGF and VEGF growth factors over periods of 1, 8, 24, 72, and 240 h. I-PRF and blood clot samples were biologically characterized using histological and immunohistochemistry analysis for IL-10, osteocalcin, and TGF-ß. Scanning electron microscopy (SEM) was used to inspect the fibrin network and distribution of blood platelets and leukocytes. Reverse transcriptase polymerase chain reaction (RT-PCR) method was used to evaluate gene expression for type I collagen. RESULTS: A higher concentration of platelets and lymphocytes was recorded in i-PRF than in peripheral blood (p < 0.05). The release of VEGF was higher in blood clot samples (1933 ± 704) than that for i-PRF (852 ± 376; p < 0.001). Immunohistochemistry showed upregulation of TGF-B, IL-10, and osteocalcin in the i-PRF group. RT-PCR showed increased type I collagen gene expression in i-PRF (p < 0.05). SEM images revealed agglomeration of platelets in some regions, while a fibrin networking was noticeable in the entire i-PRF sample. CONCLUSIONS: Injectable platelet rich fibrin becomes a good approach for soft and mineralized tissue healing considering the formation of a three-dimensional fibrin network embedding platelets, leukocytes, type I collagen, osteocalcin, and growth factors. Indeed, the injectable platelet rich fibrin can be indicated in several medical applications regarding bioactivity, simplied technique, and flowable mixing with other biomaterials. CLINICAL RELEVANCE: Morphological, cell, and protein characterization of platelet rich fibrin provides a better understanding of the clinical effects and improvement of clinical guidelines for several medical applications. Once well physicochemical and biologically characterized, the use of an injectable platelet rich fibrin can be extended to other applications in the field of orthopedics, periodontics, and implant dentistry on the repairing process of both soft and mineralized tissues.
Assuntos
Fibrina Rica em Plaquetas/química , Fibrina Rica em Plaquetas/citologia , Adulto , Plaquetas/citologia , Colágeno Tipo I/química , Fibrina/química , Humanos , Interleucina-10/química , Leucócitos/citologia , Masculino , Osteocalcina/química , Fator de Crescimento Transformador beta1/química , Fator A de Crescimento do Endotélio Vascular/químicaRESUMO
Miller's class I gingival recessions (GR) have been treated using coronally advanced flap (CAF) with platelet-rich fibrin membrane (PRF membrane) or connective tissue graft (CTG). The aim of this study was to evaluate the effect of different multiple layers of PRF membranes for the treatment of GR compared with the CTG procedure. Sixty-three Miller class I GR were treated in this study. Twenty-one GR selected randomly were treated with two layers of PRF membranes+CAF in 2PRF+CAF (test group-1), four layers of PRF membranes+CAF in 4PRF+CAF (test group-2), and CTG+CAF in the control group. The plaque index (PI), gingival index (GI), probing depth (PD), keratinized tissue thickness (KTT), clinical attachment level (CAL), recession depth (RD), recession width (RW), and keratinized tissue height (KTH) measurements were performed at baseline and 1, 3, and 6 months after surgery. The post-operative discomfort of patients, assessed with the visual analog scale (VAS) and healing index (HI), was recorded after surgery. PI, GI, and PD scores were similar for all patients at all times. RD and RW scores were similar for each patient at 1 month, but these values were significantly increased in the subsequent periods in test group-1. The increase in KTT was significantly higher in the control group compared with the test groups. Similar root coverage scores were obtained in the test group-2 and control groups, and these scores were significantly higher compared with test group-1. The PRF membrane+CAF technique may be an alternative to the CTG+CAF technique for postoperative patient comfort. However, PRF membranes should use as many layers as possible.
Assuntos
Retração Gengival/tratamento farmacológico , Retração Gengival/cirurgia , Fibrina Rica em Plaquetas/química , Retalhos Cirúrgicos , Adulto , Análise de Variância , Tecido Conjuntivo/transplante , Índice de Placa Dentária , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice Periodontal , Período Pós-Operatório , Valores de Referência , Reprodutibilidade dos Testes , Estatísticas não Paramétricas , Fatores de Tempo , Resultado do Tratamento , Escala Visual Analógica , Adulto JovemRESUMO
Abstract Miller's class I gingival recessions (GR) have been treated using coronally advanced flap (CAF) with platelet-rich fibrin membrane (PRF membrane) or connective tissue graft (CTG). Objective: The aim of this study was to evaluate the effect of different multiple layers of PRF membranes for the treatment of GR compared with the CTG procedure. Material and Methods: Sixty-three Miller class I GR were treated in this study. Twenty-one GR selected randomly were treated with two layers of PRF membranes+CAF in 2PRF+CAF (test group-1), four layers of PRF membranes+CAF in 4PRF+CAF (test group-2), and CTG+CAF in the control group. The plaque index (PI), gingival index (GI), probing depth (PD), keratinized tissue thickness (KTT), clinical attachment level (CAL), recession depth (RD), recession width (RW), and keratinized tissue height (KTH) measurements were performed at baseline and 1, 3, and 6 months after surgery. The post-operative discomfort of patients, assessed with the visual analog scale (VAS) and healing index (HI), was recorded after surgery. Results: PI, GI, and PD scores were similar for all patients at all times. RD and RW scores were similar for each patient at 1 month, but these values were significantly increased in the subsequent periods in test group-1. The increase in KTT was significantly higher in the control group compared with the test groups. Similar root coverage scores were obtained in the test group-2 and control groups, and these scores were significantly higher compared with test group-1. Conclusions: The PRF membrane+CAF technique may be an alternative to the CTG+CAF technique for postoperative patient comfort. However, PRF membranes should use as many layers as possible.