Effect of radiotherapy on the differentiation and osteogenic activity of mesenchymal stem cells on dental implants / Efeito da radioterapia na diferenciação e atividade osteogênica de células-tronco mesenquimais em implantes dentários

Objective: to evaluate the differentiation and gene expression of transcripts related to osteogenesis in a primary culture of Mesenchymal Stem Cells (MSCs) derived from rat femurs submitted to radiotherapy and the installation of pure titanium implants. Material and Methods: fifty-four rats received titanium implants in both femurs and were divided into three groups: Control: implant surgery (C); Implant + immediate irradiation (IrI), and Implant + late irradiation (IrL). Euthanasia occurred 3, 14, and 49 days after surgery. The bone marrow MSCs from the femurs were isolated and cultivated. The cell viability, total protein content, alkaline phosphatase (ALP) activity, and the formation of mineralization nodules and cellular genotoxicity were analyzed. The gene expression of Alkaline Phosphatase (phoA), Collagen 1 (COL1), Runt-related transcription factor 2 (RUNX2), Osterix (OSX), Osteopontin (OPN), Integrin ß1(ITGB1), Bone Sialoprotein (BSP), Osteonectin (SPARC), Osteocalcin (Bglap), Transforming Growth Factor ß-type (TGF-ß), Granulocyte Macrophage Colony Stimulating Factor (GM-CSF), Interleukin-6 (IL-6), Apolipoprotein E (APOE) and Prostaglandin E2 synthase (PGE2) were evaluated by qRT- PCR. Results: ionizing radiation suppresses the gene expression of essential transcripts for bone regeneration, as well as cellular viability, as observed in the IrI and IrL groups. Conclusion: although this can lead to the loss of osseointegration and failure of the implant, the MSCs showed more activity at 49 days than at 3 and 14 days. (AU)

Objetivo: avaliar a diferenciação e expressão gênica de transcritos relacionados à osteogênese em cultura primária de MSCs derivadas de fêmures de ratos submetidos à radioterapia e instalação de implantes de titânio puro. Material e Métodos: cinquenta e quatro ratos receberam implantes de titânio em ambos os fêmures e foram divididos em três grupos: Controle: cirurgia de implante (C); Implante + irradiação imediata (IrI) e Implante + irradiação tardia (IrL). A eutanásia ocorreu 3, 14 e 49 dias após a cirurgia. As MSCs de medula óssea dos fêmures foram isoladas e cultivadas. Foram analisadas a viabilidade celular, teor de proteína total, atividade da fosfatase alcalina (ALP), formação de nódulos de mineralização e genotoxicidade celular. A expressão gênica de Fosfatase Alcalina (phoA), Colágeno 1 (COL1), fator de transcrição relacionado a Runt 2 (RUNX2), Osterix (OSX), Osteopontina (OPN), Integrina ß1 (ITGB1), Sialoproteína Óssea (BSP), Osteonectina (SPARC), Osteocalcina (Bglap), Fator de Crescimento Transformador tipo ß (TGF-ß), Fator Estimulante de Colônia de Granulócitos-Macrófagos (GM-CSF), Interleucina-6 (IL-6), Apolipoproteína E (APOE) e Prostaglandina E2 sintase (PGE2) foram avaliados por qRT-PCR. Resultados: a radiação ionizante suprime a expressão gênica de transcritos essenciais para a regeneração óssea, bem como a viabilidade celular, como observado nos grupos IrI e IrL. Conclusão:embora isso possa levar à perda da osseointegração e falha do implante, as MSCs apresentaram maior atividade aos 49 dias do que aos 3 e 14 dias (AU)

Fibrina rica en plaquetas aplicada en conjunto con biomodificación alveolar en la regeneración ósea guiada. Reporte de caso / Platelet rich fibrin applied in conjunction with alveolar biomodification in guided bone regeneration. Case report

Resumen Debido a los diferentes problemas existentes a la hora de realizar procedimientos implantológicos por la calidad del remanente óseo y el estado de los tejidos periodontales en la zona a rehabilitar, existen opciones de regeneración ósea inducida que muestran tasas de éxito considerablemente favorables al ser empleadas en casos donde es necesario una regeneración ósea extensa capaz de soportar un implante dental. El objetivo del presente estudio es describir el éxito en la regeneración ósea por medio de alternativas combinadas de fibrina rica en plaquetas y modificación biológica con tetraciclina. Reporte del caso clínico: paciente femenina de 67 años que consulta por inflamación, supuración y dolor en la zona antero-superior. Es diagnosticada como absceso periapical crónico, se hace cirugía de extracción de órganos dentales, posterior a eso se hace descontaminación y adaptación de los alveolos con tetraciclina para realizar la regeneración ósea guiada con fibrina rica en plaquetas, hueso tipo Lumina Bone Porous y Lumina Coat, luego se espera el proceso de evolución para colocación de implantes dentales. El éxito obtenido con el uso de fibrina rica en plaquetas y la biomodificacion ósea como coadyuvante en la desinfección de la zona a tratar, logró mostrar resultados altamente favorables en el proceso de regeneración ósea guiada.

Abstract As the different problems that exist when carrying out implant procedures due to the quality of the bone remnant and the state of the existing periodontal tissues in the area to be rehabilitated, there are induced bone regeneration options that show considerably favorable success rates as they are used in cases where extensive bone regeneration is necessary to support a dental implant. The objective of the present study is to describe the success in bone regeneration using combined alternatives of platelet-rich fibrin and biological modification with tetracycline. Report of the clinical case: 67-year-old female patient consulted for inflammation and suppuration and pain in the upper antero-superior area, she was diagnosed as chronic periapical abscess, dental organ extraction surgery was performed, after that decontamination and adaptation of the alveoli was performed with tetracycline to perform guided bone regeneration with platelet-rich fibrin, Coat membrane and Lumina bone criteria, then wait for the evolution process to place dental implants. The success obtained with the use of FRP and bone biomodification as an adjuvant in the disinfection of the area to be treated achieved to show highly favorable results in the guided bone regeneration process.

Analysis of the biocompatibility of a biocelulose and a poly L- lactic acid membrane

The use of selective barriers as resorbable membranes has become a routine clinical procedure for guided bone regeneration. Therefore, the production of membranes with a low inflammatory potential during their resorption process has become the goal of a considerable number of researches. Aim: The purpose of the present study was to evaluate the biocompatibility of poly (L- lactic acid) (PLLA) and biocelulose membranes (BC) inserted in the subcutaneous tissue on the dorsum of rats. Methods: Fifteen animals underwent surgical procedures for the insertion of 4 types of membranes: COL (Collagen membrane) ­ Control Group; BC (Biocellulose membrane); BCAg (Biocellulose membrane impregnated with Silver); PLLA (Poly (L-lactic acid) membrane). All membrane types were inserted into each animal. Animals were euthanized after 3, 7, and 15 days of the surgical procedure. Descriptive histological analyses were carried out to investigate host tissue reaction to membrane presence by assessing the anti-inflammatory process composition associated with the membrane resorption and the presence of foreign-body reaction or encapsulation. Results: The BC membranes showed a higher degree of inflammation and poor pattern of integration with the surrounding tissues than the PLLA and COL membranes. Conclusion: The PLLA and COL membranes present better biocompatibility than the BC membranes

Estrés agudo y crónico en la reparación ósea: un enfoque actualizado desde las Neurociencias / Acute and chronic stress in bone repair: an updated approach from the Neurosciences

Los mecanismos moleculares fisiológicos asociados a la respuesta ante el estrés agudo y crónico permiten entender los cambios que éstos pueden producir en los diversos tejidos del cuerpo. Diversas investigaciones resaltan el papel del estrés crónico en el desarrollo de disfunciones que afectan el equilibrio corporal; sin embargo, hay que considerar que los mecanismos relacionados con el estrés agudo, también pueden influir en el desarrollo de patologías y de la progresión de las manifestaciones deletéreas del estrés crónico. Por otro lado, uno de los tejidos más estudiados en los últimos años ha sido el tejido óseo, ya que éste se encuentra influenciado por factores nerviosos, endocrinos e inmunológicos. Esta revisión busca analizar las bases neurocientíficas de los mecanismos moleculares del estrés y su relación en el proceso de reparación ósea. Para esto, se realizó una búsqueda de la literatura en las bases de datos de Pubmed, Scopus y ScienceDirect, concluyendo que el estrés modifica la liberación de neurotransmisores, la acción del sistema nervioso autónomo, la liberación de hormonas corticotrópicas y la actividad de diversas citocinas; lo que conlleva al desequilibrio de los procesos de regulación y reparación del tejido óseo sometido a carga o lesión.

The physiological molecular mechanisms associated with the response to acute and chronic stress allow us to understand the changes that these can produce in the various tissues of the body. Various investigations highlight the role of chronic stress in the development of dysfunctions that affect body balance; However, it must be considered that the mechanisms related to acute stress can also influence the development of pathologies and the progression of the deleterious manifestations of chronic stress. On the other hand, one of the most studied tissues in recent years has been bone tissue, since it is influenced by nervous, endocrine and immunological factors. This paper seeks to analyze the neuroscientific bases of the molecular mechanisms of stress and their relationship in the bone repair process. Therefore, a literature search was carried out in the Pubmed, Scopus and ScienceDirect databases. Concluding that stress modifies the release of neurotransmitters, the action of the autonomic nervous system, the release of corticotropic hormones and the activity of various cytokines; which leads to the imbalance of the regulation and repair processes of the bone tissue subjected to load or injury.

Aplicações da dentina autógena na regeneração óssea: revisão integrativa de literatura / Applications of dentine in bone regeneration: integrative literature review

A dentina e o osso alveolar apresentam muita semelhança em sua composição. Sendo assim, podemos considerar a utilização da dentina como recurso alternativo nas intervenções que buscam a regeneração tecidual óssea. Objetivo: o presente estudo realizou uma revisão integrativa da literatura sobre o uso da dentina como biomaterial para regeneração óssea. Metodologia: foi realizada uma busca por artigos, nas bases de dados Medline, via PubMed; Scielo, LILACS, BASE, Scopus e Science Direct, queavaliassem ou descrevessem o uso da dentina como biomaterial para regeneração óssea. Foram utilizados os seguintes descritores: "Dentin" AND "Bone Regeneration", sem delimitação de tempo. Os critérios de inclusão foram: estudos clínicos publicados em periódicos, oriundos de dados primários, sobre o uso de dentina como biomaterial. Os critérios de exclusão foram: revisões de literatura, estudos in vitro e em animais, estudos que não fosse possível o acesso na íntegra e estudos que associassem o uso da dentina com outros biomateriais sem que fosse possível relacionar os resultados apenas pelo uso da dentina. Resultados: vinte e três estudos foram selecionados para a presente revisão. As pesquisas demonstraram que há uma heterogenicidade relacionada ao tamanho da partícula de dentina obtida, que pode ser decorrente de diferentes métodos de processamento. Conclusão: a reutilização da dentina como biomaterial pode ser uma alternativa promissora ao enxerto autógeno. Sugere-se, então, que protocolos de processamento da partícula de dentina sejam melhor estabelecidos e estudos longitudinais precisam ser realizados para a garantia de procedimentos seguros, eficazes e práticos.

The dentin and the alveolar bone are very similar in composition, therefore, it's usage as an alternative resource in interventions that seek tissue regeneration can be considered. Objective: the aim of the present study was to carry out an integrative review of the literature on the use of dentin as a biomaterial for bone regeneration. Methodology: a search for articles was carried out in the Medline databases, via PubMed; Scielo, LILACS, BASE, Scopus and Science Direct, which evaluated or described the use of dentin as a biomaterial for bone regeneration. The following descriptors were used: "Dentin" AND "Bone Regeneration", without time limits. The inclusion criteria were: clinical studies published in journals, derived from primary data, on the use of dentin as a biomaterial. Exclusion criteria were: literature reviews, in vitro and in animal studies, studies that were not possible to be accessed in full and studies that associated the usage of dentin with other biomaterials and that it was not possible to relate the results just by using the dentin. Results: twenty-three studies were selected for the present review. Researches have shown that there is heterogeneity related to the size of the obtained dentin particle, which may be due to different processing methods. Conclusion: the reuse of dentin as a biomaterial can be a promising alternative to autogenous graft. It is suggested, then, that dentin particle processing protocols should are better established and longitudinal studies need to be carried out to the in order to ensure safe, effective and practical procedures.

Células madre en odontología: nuevas perspectivas / Stem cells in dentistry: new perspectives

En el campo de la odontología, prevalecen actualmente alternativas terapéuticas con una filosofía conservadora. Sin embargo, con el advenimiento de los tratamientos con células madre (CM), se amplían las posibilidades terapéuticas, que buscan la combinación y el equilibrio entre la intervención tradicional y las posibilidades de reposición de estructuras anatómicas dañadas, a través de la regeneración de tejidos utilizando células madre o sus derivados (AU)

In the dentistry field, therapeutic alternatives with a conservative philosophy currently prevail. However, with the advent of stem cell (SC) treatments, therapeutic possibilities are expanding, seeking a combination and balance between traditional intervention and the pos- sibility of replacing damaged anatomical structures through tissue regeneration, using stem cells or their derivatives (AU)

Biología del tejido óseo y cambios morfológicos en su regeneración / Biology of bone tissue and morphological changes in its regeneration

Introducción: La regeneración ósea permite la reintegración y conformación de tejidos posteriores a la extracción o corrección de un defecto óseo. Es considerada una técnica de estimulación para la formación de hueso nuevo, donde se favorece la construcción y la preservación del coágulo con el fin de evitar la infiltración en la zona de reparación, de componentes celulares (células epiteliales y conjuntivas). Objetivos: Describir los cambios a nivel morfológico durante el proceso de regeneración ósea y mencionar distintas técnicas de preservación ósea y los factores necesarios para su realización. Presentación de caso: Paciente femenina con periodontitis apical asintomática en órganos dentarios 34 y 37, que se sometió a preservación alveolar mediante la práctica de exodoncia atraumática y regeneración ósea con xenoinjerto, colocación de membrana colágeno e implante posextractivo inmediato. Principales comentarios: La colocación inmediata de implantes posexodoncia permite una buena preservación del alveolo, siempre y cuando las condiciones clínicas del paciente así lo permitan, por ejemplo, la ausencia de procesos infecciosos agudizados como en el presente caso. La regeneración ósea, en el defecto producido por el proceso inflamatorio periapical, implicó una correcta detoxificación de la zona a través del curetaje y la aplicación de antibióticos. La respuesta inmunológica exagerada ante injertos óseos no es frecuente; sin embargo, en este caso llevó a una pérdida parcial del sustituto óseo sin comprometer el pronóstico de los implantes(AU)

Introduction: Bone regeneration allows the reintegration and conformation of tissues after the extraction or correction of a bone defect. It is considered a stimulation technique for the formation of new bone, where the construction and preservation of the clot is favored in order to avoid infiltration in the repair area of cellular components (epithelial and conjunctiva cells). Objective: Describe the changes at the morphological level during the bone regeneration process and mention different bone preservation techniques and the necessary factors for their implementation. Case presentation: Female patient with asymptomatic apical periodontitis in dental organs 34 and 37, who underwent alveolar preservation through the practice of atraumatic exodontics and bone regeneration with xenograft, collagen membrane placement and immediate post-extraction implant. Main comments: The immediate placement of post-exodontic implants allows a good preservation of the alveolus, as long as the clinical conditions of the patient allow it, for example, the absence of exacerbated infectious processes as in the present case. Bone regeneration, in the defect produced by the periapical inflammatory process, involved a correct detoxification of the area through curettage and the application of antibiotics. Exaggerated immune response to bone grafts is not common; however, in this case it led to a partial loss of bone substitute without compromising the prognosis of the implants(AU)

Influencia de diferentes materiales de relleno en alvéolos post exodoncia de ratas ovariectomizadas (OVX) / Influence of different graft materials on post extraction sockets of ovariectomized rats (OVX)

RESUMEN: El objetivo del presente estudio fue establecer la influencia de diferentes materiales en el proceso de regeneración ósea de alveolos post exodoncia de ratas hembra adultas ovariectomizadas (OVX). Para ello, se utilizaron 40 ratas sprague dawley, divididas en grupo experimental (OVX) (n=20) y grupo control (Sin ovariectomía) (n=20). Todas las ratas del grupo experimental fueron sometidas a ovariectomía bilateral para simular un estado de osteoporosis inducida por déficit de estrógeno. Posterior a 12 semanas post OVX, las ratas de ambos grupos fueron divididas en 4 subgrupos, en los cuales fue extraído el primer molar superior derecho de cada rata. Posteriormente, las terapias realizadas en los alveolos post-exodoncia fueron: A: (N=5) Alveolo no rellenado para ser utilizado como control negativo. B: (N=5) Aplicación de injerto bifásico (HA+BTCP). C: (N=5) Aplicación de PRF. D: Aplicación de una combinación de injerto bifásico + PRF. Luego de tres semanas se realizó la eutanasia de los animales y obtención de las muestras para los análisis respectivos. Todos los animales sobrevivieron al final del estudio sin ninguna complicación postoperatoria. Los resultados cuantitativos del área ósea interradicular del segundo molar superior, mostraron diferencias estadísticamente significativas entre grupo control y grupo OVX. Mientras que no se observaron diferencias en la descripción histológica ni en el análisis cuantitativo de fibras colágenas tipo I y III. Es posible concluir que el modelo de osteoporosis inducida por déficit de estrógeno modificaría también la microarquitectura ósea de la Maxila. No obstante, nuevos estudios son necesarios para continuar con el estudio de biomateriales para regeneración ósea en modelos de osteoporosis inducida.

SUMMARY: The aim of the present study was to establish the influence of different materials on the process of bone regeneration in post-extraction sockets of ovariectomized (OVX) adult female rats. For this, 40 Sprague Dawley rats were used, divided into an experimental group (OVX) (n=20) and a control group (without ovariectomy) (n=20). All rats in the experimental group underwent bilateral ovariectomy to simulate a state of estrogen deficiency osteoporosis. After 12 weeks post OVX, rats from both groups were divided into 4 subgroups, in which the upper right first molar of each rat was extracted. Subsequently, the therapies performed in the post-extraction sockets were A: (N=5) Unfilled alveolus to be used as a negative control. B: (N=5) Biphasic graft application (HA+BTCP). C: (N=5) PRF application. D: Application of a combination of biphasic graft + PRF. After three weeks, the animals were euthanized, and the samples were obtained for the respective analyses. All animals survived to the end of the study without any postoperative complications. The quantitative results of the interradicular bone area of ??the upper second molar showed significant differences between the control group and the OVX group. While no differences were observed in the histological description or in the quantitative analysis of collagen fibers type I and III. It is possible to conclude that the model of osteoporosis induced by estrogen deficiency would modify the bone microarchitecture of the Maxilla. However, new studies are necessary to continue with the study of biomaterials for bone regeneration in models of induced osteoporosis.

Análise comparativa entre técnicas cirúrgicas de enxertia óssea em reabilitação de maxila atrófica: transplante celular odontológico (TCO) e técnica convencional de enxertia óssea ­ relato de caso clínico / Comparative analysis between surgical techniques of bone grafting in rehabilitation of atrophic maxilla: dental cell transplantation (OCT) and conventional bone grafting technique - a case report

A reabilitação de maxila atrófica se apresenta ainda nos dias de hoje como um desafio anatômico/fisiológico para os profissionais da área odontológica que visam buscar a instalação de implantes para futuras reabilitações protéticas, tendo em vista o grau de dificuldade de reconstituição do rebordo alveolar perdido. Com o intuito de reabilitar essas maxilas frente às adversidades, diferentes técnicas são propostas tais como enxertos ósseos autógenos, homógenos, substitutos ósseos alógenos, xenógenos e aloplásticos e suas respectivas técnicas. O objetivo deste trabalho foi apresentar um relato de caso clínico, no qual duas técnicas de reconstituição de rebordo alveolar de hemi-arco foram realizadas na mesma maxila utilizando biomaterial em bloco, visando comparar os resultados histológicos e clínicos. Após 5 meses da realização da enxertia, foi coletado material dos enxertos alveolares bilateralmente utilizando-se brocas trefinas para estudo histológico. Através da metodologia empregada, pode-se observar maior formação de estrutura óssea no lado em que foi praticada a metodologia transplantes celular odontológico (TCO), que preconiza a associação de sangue medular mandibular ao biomaterial, em relação a técnica contralateral em que utilizou a metodologia convencional, que preconiza a associação ao biomaterial do sangue periférico. Pode-se observar através da metodologia empregada que a utilização de biomateriais potencializados com sangue medular mandibular apresentou maior crescimento de estrutura óssea, incrementando em torno de 35% a mais na neoformação.de osso vital.

The rehabilitation of atrophic maxilla is still presented today as an anatomical/physiological challenge for professionals in the dental field who aim to seek the installation of implants for future prosthetic rehabilitations, in view of the degree of difficulty in reconstituting the lost alveolar ridge. In order to rehabilitate these jaws in the face of adversity, different techniques are proposed such as autogenous, homogenous bone grafts, allogeneic, xenogenous and alloplastic bone substitutes and their respective techniques. The aim of this study was to present a clinical case report, in which two hemi-arch alveolar ridge reconstruction techniques were performed in the same maxilla using biomaterial en bloc, in order to compare the histological and clinical results. After 5 months of grafting, material was collected from the alveolar grafts bilaterally using trephine burs for histological study. Through the used methodology, it was possible to see greater bone formation of structure on the side in which the dental cell transplantation (TCO) methodology was practiced, which advocates the association of mandibular medullary blood to the biomaterial, in relation to the contralateral technique in which the methodology was used conventional method, which advocates the association with peripheral blood biomaterial. It can be observed through the used methodology that the use of biomaterials potentiated with mandibular medullary blood showed greater growth of bone structure, increasing around 35% more in the neoformation of vital bone.

Vertical bone augmentation with guided bone regeneration: a scoping review / Aumento óseo vertical con regeneración ósea guiada: scoping review

Introduction: There are multiple techniques for vertical bone augmentation. Guided bone regeneration is one of them; however, the literature is diverse and includes different study designs, which makes it difficult to synthesize results. Objective: To analyze the general technical characteristics, clinical results, and complications of vertical bone augmentation performed with guided bone regeneration in humans. Material and Methods: This scoping review was based on the PRISMA-ScR guidelines. A search was performed in the Pubmed, Scielo, and Worldcat databases. Papers published from 1990 to April 2020 were included in the study. Research articles not conducted in humans or published in languages other than English and Spanish were excluded. Title and abstract were screened by two reviewers, then full studies were extracted, and data tabulated. Results: 89 studies were included. The highest percentage reported having obtained a vertical bone increase of less than 5 mm and having used non-resorbable membranes. The most frequent type of graft is autogenous and combinations of grafts, the most common being autogenous with xenograft. All studies that reported bone stability of implants in regenerated bone were favorable, as was implant survival, reporting values between 83.8% and 100%. Membrane exposure is the most frequently reported complication, followed by infection or abscesses, and tissue dehiscence. Conclusion: Vertical bone regeneration is a reliable technique, with high predictability and low incidence of complications compared to other vertical bone augmentation techniques.

Introducción: Existen múltiples técnicas para el aumento óseo vertical siendo una opción la regeneración ósea guiada, sin embargo, la literatura es diversa y con distintos diseños que dificultan la síntesis de resultados. Objetivo: Analizar las características generales técnicas, resultados clínicos y complicaciones del aumento óseo vertical realizado con regeneración ósea guiada en humanos. Material y Métodos: Esta revisión de alcance se basó en la guía PRISMA-ScR. Se realizó una búsqueda en las bases de datos Pubmed, Scielo y Worldcat. Fueron incluidos aquellos publicados desde el año 1990 hasta abril de 2020. Se excluyeron los estudios no realizados en humanos o publicados en idiomas distintos al inglés y español. Dos revisores examinaron título y resumen, luego los estudios completos se extrajeron y se ordenaron los datos en tablas. Resultados: 89 estudios fueron incluidos. El mayor porcentaje reportó haber obtenido un aumento óseo vertical menor a 5 mm y haber utilizado membranas no reabsorbibles. El tipo de injerto que más frecuente es el autógeno y las combinaciones de injertos, siendo el más común autógeno con xenoinjerto. Todos los estudios que reportaron estabilidad ósea de implantes en hueso regenerado fueron favorables, al igual que la supervivencia de implantes, reportando valores entre 83,8% y 100%. La exposición de membrana es la complicación que más se repite en los estudios, seguido por infección o abscesos y dehiscencia de tejidos. Conclusión: La regeneración ósea vertical es una técnica confiable, con alta predictibilidad y baja incidencia de complicaciones en comparación a otras técnicas de aumento óseo vertical.

3D spheroid cell cultures and their role in bone regeneration: a systematic review / Cultivos de esferoides 3D y su papel en la regeneración ósea: una revisión sistemática

Abstract Recently, the 3D spheroid cell culture application has been extensively used in the treatment of bone defects. A wide variety of methodologies have been used, which has made the comparison of results complex. Therefore, this systematic review has two aims: (i) to perform an analysis focused on the role of 3D spheroid cell culture in bone regeneration strategies; and (ii) address the main challenges in clinical application. A search of the following keywords "3D cell culture", "spheroid", and "bone regeneration" was carried out in the PubMed, Scopus, and ScienceDirect databases and limited to the years 2010-2020. Studies were included if their primary objective was the behavior of cell aggregates to formed spheroids structures by different 3D cell culture techniques focused on the regeneration of bone tissue. To address the risk of bias for in vitro studies, the United States national toxicology program tool was applied, and descriptive statistics of the data were performed, with the SPSS V.22 program. A total of 16 studies were included, which met the established criteria corresponding to in vitro and in vitro/in vivo studies; most of these studies used stem cells for the 3D cell spheroids. The most often methods used for the 3D formation were low adherence surface and rotational methods, moreover, mesenchymal stem cells were the cell line most frequently used because of their regenerative potential in the field of bone tissue engineering. Although the advances in research on the potential use of 3D spheroids in bone regeneration have made great strides, the constant innovation in cell spheroid formation methodologies means that clinical application remains in the future as strategy for 3D tissue bioprinting.

Resumen Recientemente, la aplicación del cultivo 3D de esferoides se ha utilizado ampliamente en el tratamiento de defectos óseos. La variedad de metodologías para lograr los cultivos 3D de esferoides ha hecho compleja la comparación de resultados. Por tanto, esta revisión sistemática tiene dos objetivos: (i) realizar un análisis centrado en el papel de los cultivos 3D de esferoides en las estrategias de regeneración ósea; y (ii) abordar los principales desafíos en la aplicación clínica. Se realizó una búsqueda de las siguientes palabras clave "cultivo celular 3D", "esferoide" y "regeneración ósea" en las bases de datos PubMed, Scopus y ScienceDirect y se limitó a los años 2010-2020. Se incluyeron los estudios si su principal objetivo era el comportamiento de agregados celulares para generar las estructuras esferoidales desarrollados por diferentes técnicas de cultivo celular 3D enfocadas a la regeneración del tejido óseo. Para abordar el riesgo de sesgo de los estudios in vitro, se aplicó la herramienta del programa nacional de toxicología de Estados Unidos y se realizaron estadísticas descriptivas de los datos, con el programa SPSS V.22. Se incluyeron un total de 16 estudios, que cumplieron con los criterios establecidos correspondientes a estudios in vitro e in vitro/in vivo; la mayoría de estos estudios utilizaron células troncales para generar los esferoides celulares 3D. Los métodos más utilizados para la formación de los esferoides 3D fueron la superficie de baja adherencia y los métodos de rotación, asimismo, la línea celular de células troncales mesenquimales fueron las más utilizadas debido a su gran potencial regenerativo en el campo de la ingeniería de tejidos óseos. Aunque los avances en la investigación sobre el uso potencial de los cultivos celulares de esferoides 3D en la regeneración ósea han logrado grandes avances, la constante innovación en las metodologías de la generación de esferoides 3D deja claro que la aplicación clínica de estos permanecerá en el futuro como estrategia en la bioimpresión tisular.

The influence of haematogenous bone marrow on the early osseointegration of a titanium implant which penetrates the endosteum / La influencia de la médula ósea hematógena en la osteointegración temprana de un implante de titanio que penetra en el endostio

SUMMARY: The utility of metallic bio-medical implants in osseous or dental affections is irrefutable. The paper aims to test the tolerance of the bone marrow to titanium implants. Titanium implants were inserted in the femur of 11-months old rabbits. The implants penetrated the endosteum, half of their length getting into the haematogenous bone marrow. Seven days after the insertion we collected bone fragments containing the implant. The CT exam revealed a significant decrease in the density of the bone at the interface with the implant and a more discrete one aloof from the insertion area. The histologic exam after 7 days revealed osseous reparatory processes only in the endosteal area from where it expanded on the surface of the implant which was inside the marrow. The presence and intensity of the osseous reparatory processes after only seven days post-implant demonstrates that the marrow actively participates in bone regeneration and implants osseointegration.

RESUMEN: La utilidad de los implantes biomédicos metálicos en afecciones óseas o dentales es irrefutable. El documento tiene como objetivo probar la tolerancia de la médula ósea a los implantes de titanio. Se insertaron implantes de titanio en el fémur de conejos de 11 meses. Los implantes penetraron en el endostio y la mitad de su longitud penetró en la médula ósea hematógena. Siete días después de la inserción, recolectamos fragmentos de hueso que contenían el implante. El examen de TC reveló una disminución significativa en la densidad del hueso en la interfaz con el implante y una más discreta alejada del área de inserción. El examen histológico a los 7 días reveló procesos de reparación ósea solo en el área endóstica desde donde se expandió en la superficie del implante que estaba dentro de la médula. La presencia e intensidad de los procesos de reparación ósea después de solo siete días del implante demuestra que la médula ósea participa activamente en la regeneración ósea y en la osteointegración de los implantes.

Regeneração óssea guiada de alveolos de extração dentária - uma revisão / Guided bone regeneration of alveoli tooth extraction - a review

O osso é um tecido conjuntivo especializado, vascularizado e dinâmico que se modifica ao longo do organismo. Quando lesado, possui uma capacidade única de regeneração e reparação sem a presença de cicatrizes, mas em algumas situações devido tamanho do defeito ósseo não se regenera por completo. Assim, se faz necessária a realização de procedimentos de regeneração óssea guiada. Para isso, o implantodontista deve conhecer as bases biológicas da regeneração óssea guiada alveolar e suas indicações. Nesta revisão foram abordadas indicações, vantagens e tipos de biomateriais utilizados para preenchimento do alvéolo dentário imediatamente após a extração dentária sempre que o objetivo for à reabilitação através da instalação de implantes. Mesmo este, biomateriais, apresentando inúmeras qualidades, estudos ainda devem ser feitos a fim de obter a cada dia, um material sintético compatível com o tecido ósseo perdido em quantidades adequadas sem necessitar de cirurgias extra-bucais.

Bone is a specialized vascularized connective tissue that dynamic changes throughout the body. When injured, it has a unique ability to regenerate and repair without the presence of scars, but in some situations due to size of the bone defect does not regenerate completely. Thus, it is necessary to perform guided bone regeneration procedures. For this, the implant dentistry must know the biological bases of alveolar guided bone regeneration and its indications. In this review were addressed indications, advantages and types of biomaterials used for filling the tooth socket immediately after the tooth extraction whenever the goal is rehabilitation through implants installation. Even this, biomaterials, having several qualities, further studies must be done to obtain each day, a synthetic material compatible with the bone tissue lost in proper amounts without the need of extra-oral surgery.

Glass ionomer heated or not to identify bone defect created in rat calvaria / Ionômero de vidro aquecido ou não para identificação de defeitos ósseos criados em calvárias de ratos

Introduction: Some experimental models have been used to evaluate the use of biomaterials in bone regeneration. Among them are the critical size defects (CSD) created in rat calvaria. An experimental model has been described in the literature, in which "L" markings are performed on the margins of the bone defects in order to assist in the precise identification of these defects during laboratory processing and analysis of the results. In the proposed model, the "L" markings are filled with amalgam. Objective: The purpose of the present study was to evaluate the amalgam replacement of an experimental bony defect model in rat calvaria by heated or unheated glass ionomer. Material and method: 24 rats were used. A 5 mm CSD was created at each animal calvaria. Two "L" shaped markings were made 2 mm from the margins of the bone defect, filled with amalgam (Group AM), heated glass ionomer cement (Group GIh) or not (Group GI). The animals were euthanized 15 days postoperatively. The areas of the surgical defect and the L-shaped marking were histomorphometrically analyzed and the data were analyzed statistically (p <0.05). Result: There were no significant clinical, histological or methodological differences among the experimental groups. Conclusion: It can be concluded that GI can replace AM in the proposed experimental model and GI heating did not promote additional benefits.

Introdução: Alguns modelos experimentais têm sido usados para avaliar o uso de biomateriais na regeneração óssea. Entre eles estão os defeitos de tamanho crítico (DTC) criados em calvárias de ratos. Um modelo experimental foi descrito na literatura onde marcações em L são realizadas nas margens do defeito ósseo para auxiliar na identificação precisa desses defeitos durante o processamento laboratorial e análise dos resultados. No modelo experimental proposto, as marcações em "L" são preenchidas com amálgama. Objetivo: Avaliar a substituição do amálgama por ionômero de vidro aquecido ou não em um modelo experimental para identificação de defeito ósseo criado em calvária de ratos. Material e método: Foram utilizados 24 ratos. Um DTC de 5 mm de diâmetro foi criado na calvária de cada animal. Duas marcações em "L" foram realizadas a 2 mm das margens do defeito ósseo, preenchidas com amálgama (Grupo AM), ionômero de vidro aquecido (Grupo CIVaq) ou não (Grupo CIV). Os animais foram eutanasiados aos 15 dias pós-operatórios. A área do defeito cirúrgico e das marcações em "L" foram histomorfometricamente avaliadas e os dados estatisticamente analisados (p<0,05). Resultado: Não houve diferença estatisticamente significativa entre os grupos experimentais para as análises metodológicas, clínicas ou histomorfométrica realizadas. Conclusão: Dentro dos limites deste estudo, pode-se concluir que CIV pode substituir o AM no modelo experimental proposto e o aquecimento do CIV não promoveu benefícios adicionais.

A hierarchical vascularized engineered bone inspired by intramembranous ossification for mandibular regeneration / 国际口腔科学杂志·英文版

Mandibular defects caused by injuries, tumors, and infections are common and can severely affect mandibular function and the patient's appearance. However, mandible reconstruction with a mandibular bionic structure remains challenging. Inspired by the process of intramembranous ossification in mandibular development, a hierarchical vascularized engineered bone consisting of angiogenesis and osteogenesis modules has been produced. Moreover, the hierarchical vascular network and bone structure generated by these hierarchical vascularized engineered bone modules match the particular anatomical structure of the mandible. The ultra-tough polyion complex has been used as the basic scaffold for hierarchical vascularized engineered bone for ensuring better reconstruction of mandible function. According to the results of in vivo experiments, the bone regenerated using hierarchical vascularized engineered bone is similar to the natural mandibular bone in terms of morphology and genomics. The sonic hedgehog signaling pathway is specifically activated in hierarchical vascularized engineered bone, indicating that the new bone in hierarchical vascularized engineered bone underwent a process of intramembranous ossification identical to that of mandible development. Thus, hierarchical vascularized engineered bone has a high potential for clinical application in mandibular defect reconstruction. Moreover, the concept based on developmental processes and bionic structures provides an effective strategy for tissue regeneration.

Alendronato de sódio tópico associado ao osso bovino liofilizado no reparo ósseo / Topical alendronate associated with lyophilized bovine bone in bone repair

Introdução: O osso bovino inorgânico é o enxerto mais utilizado na Odontologia, tendo como desvantagem longo tempo de integração ao leito receptor. Os bifosfonatos têm sido utilizados para modular a quantidade e a qualidade do osso regenerado e diminuir o tempo de integração do enxerto. Objetivo: Avaliar o efeito do bifosfonato alendronato de sódio (ALN) 0,5%, associado ou não ao osso bovino inorgânico, na reparação de defeitos ósseos. Material e método: Dois defeitos ósseos foram confeccionados na calvária de 12 coelhos, sendo a cavidade esquerda/experimental preenchida com: GI = osso bovino inorgânico (Bio-Oss®); GII = Bio-Oss® + ALN 0,5%; GIII = ALN 0,5%; e a cavidade direita por coágulo sanguíneo (controle). Os animais foram mortos aos 60 dias pós-operatórios. Por meio de análise histomorfométrica calculou-se o percentual de osso neoformado e remanescente do biomaterial em relação à área total do defeito. Resultado: Osso neoformado: GI = 38,16 ± 15,44%; GII = 55,77 ± 16,75%; GII I = 60,28 ± 11,45%. Controle = 45,11 ± 11,09%. Remanescente do enxerto: GI = 7,02 ± 5,36% e GII = 16,59 ± 9,56%. Não houve diferença quanto ao percentual de osso neoformado entre os grupos (ANOVA p = 0,15512; teste de Tukey F = 2,089). O percentual de remanescente do enxerto também foi estatisticamente semelhante entre os grupos GI e GII (teste de Tukey F = 5,019). Conclusão: O uso tópico da solução de ALN 0,5% isoladamente ou associado ao osso bovino liofilizado não alterou o percentual de neoformação óssea nem a degradação dos grânulos do enxerto.

Introduction: Inorganic bovine bone is the most used graft in dentistry, with the disadvantage of long integration time into the receptor bed. Bisphosphonates have been used to modulate the quantity and quality of regenerated bone and decrease graft integration time. Objective: To evaluate the effect of alendronate sodium bisphosphonate (ALN) 0.5%, associated or not with Inorganic bovine bone, in the repair of bone defects. Material and method Two bone defects were made in the calvaria of 12 rabbits, and the left/experimental cavity was filled with: GI = Inorganic bovine bone (Bio-Oss®); GII = Bio-Oss® + 0.5% ALN; GIII = 0.5% ALN; and the right cavity/blood clot control. The animals were killed at 60 days after surgery. Through histomorphometric analysis, the percentage of newly formed bone and remnant biomaterial relative to the total area of the defect was calculated. Result: Neoformed bone: GI = 38.16 ± 15.44%, GII = 55.77 ± 16.75%; GIII= 60.28 ± 11.45%; Control=45,11 ± 11,09%. Graft remnant: GI = 7.02 ± 5.36% and GII = 16.59 ± 9.56%. There was no difference in the percentage of newly formed bone between the groups (ANOVA p = 0.15512; Tukey's test F = 2.089). The percentage of graft remnant was also statistically similar between groups GI and GII (Tukey's test F = 5019). Conclusion: Topical use of 0.5% ALN solution alone or associated with lyophilized bovine bone did not change the percentage of bone neoformation, nor the degradation of graft granules.

The Evaluation of Bone Regeneration Following Socket Preservation with Concentrated Growth Factor (CGF) and Poly Lactic-Co-Glycolic Acid (PLGA) Scaffold in Rabbits

ABSTRACT@#Various grafting materials are utilised to facilitate regeneration. There is currently a paradigm shift towards applying poly lactic-co-glycolic acid (PLGA), which is regarded as an excellent scaffold for tissue engineering. Concentrated growth factor (CGF) has also been reported to promote wound healing. Nevertheless, the role of PLGA microspheres as a substitute for bone graft material with CGF in bone regeneration remains unclear. This study was designed to evaluate the effect of CGF with PLGA on bone formation and the expression of alkaline phosphatase (ALP) following socket preservation. PLGA microspheres were prepared using double solvent evaporation method and observed under scanning electron microscopy (SEM). A 6 mL of rabbit’s blood was collected from the marginal ear vein and centrifuged to obtain CGF. Blood was also collected for ALP assessment from 24 New Zealand White (NZW) male rabbits subjected to the first upper left premolar extraction. Sockets were filled with CGF, PLGA, CGF+PLGA or left empty and observed with microscopic computed tomography (micro-CT) at four weeks and eight weeks. The SEM image revealed a spherical shape with interconnected pores on the surface of the PLGA particles. Repeated measures ANOVA were used to evaluate the effect of time and treatment (p < 0.05) with significant differences in bone width, height, volume, volume fraction and expression of ALP was observed with CGF+PLGA. Both CGF and PLGA have the potential as the alternative grafting materials and this study could serve as an ideal benchmark for future investigations on the role of CGF+PLGA in bone regeneration enhancement.

The osteogenesis of Ginsenoside Rb1 incorporated silk/micro-nano hydroxyapatite/sodium alginate composite scaffolds for calvarial defect / 国际口腔科学杂志·英文版

Ginsenoside Rb1, the effective constituent of ginseng, has been demonstrated to play favorable roles in improving the immunity system. However, there is little study on the osteogenesis and angiogenesis effect of Ginsenoside Rb1. Moreover, how to establish a delivery system of Ginsenoside Rb1 and its repairment ability in bone defect remains elusive. In this study, the role of Ginsenoside Rb1 in cell viability, proliferation, apoptosis, osteogenic genes expression, ALP activity of rat BMSCs were evaluated firstly. Then, micro-nano HAp granules combined with silk were prepared to establish a delivery system of Ginsenoside Rb1, and the osteogenic and angiogenic effect of Ginsenoside Rb1 loaded on micro-nano HAp/silk in rat calvarial defect models were assessed by sequential fluorescence labeling, and histology analysis, respectively. It revealed that Ginsenoside Rb1 could maintain cell viability, significantly increased ALP activity, osteogenic and angiogenic genes expression. Meanwhile, micro-nano HAp granules combined with silk were fabricated smoothly and were a delivery carrier for Ginsenoside Rb1. Significantly, Ginsenoside Rb1 loaded on micro-nano HAp/silk could facilitate osteogenesis and angiogenesis. All the outcomes hint that Ginsenoside Rb1 could reinforce the osteogenesis differentiation and angiogenesis factor's expression of BMSCs. Moreover, micro-nano HAp combined with silk could act as a carrier for Ginsenoside Rb1 to repair bone defect.

Immunomodulatory effects and mechanisms of distraction osteogenesis / 国际口腔科学杂志·英文版

Distraction osteogenesis (DO) is widely used for bone tissue engineering technology. Immune regulations play important roles in the process of DO like other bone regeneration mechanisms. Compared with others, the immune regulation processes of DO have their distinct features. In this review, we summarized the immune-related events including changes in and effects of immune cells, immune-related cytokines, and signaling pathways at different periods in the process of DO. We aim to elucidated our understanding and unknowns about the immunomodulatory role of DO. The goal of this is to use the known knowledge to further modify existing methods of DO, and to develop novel DO strategies in our unknown areas through more detailed studies of the work we have done.

Multi-functional osteoclasts in matrix-based tissue engineering bone / 中华创伤杂志(英文版)

The repair of bone defects, especially for the large segment of bone defects, has always been an urgent problem in orthopedic clinic and attracted researchers' attention. Nowadays, the application of tissue engineering bone in the repair of bone defects has become the research hotspot. With the rapid development of tissue engineering, the novel and functional scaffold materials for bone repair have emerged. In this review, we have summarized the multi-functional roles of osteoclasts in bone remodeling. The development of matrix-based tissue engineering bone has laid a theoretical foundation for further investigation about the novel bone regeneration materials which could perform high bioactivity. From the point of view on preserving pre-osteoclasts and targeting mature osteoclasts, this review introduced the novel matrix-based tissue engineering bone based on osteoclasts in the field of bone tissue engineering, which provides a potential direction for the development of novel scaffold materials for the treatment of bone defects.