Reemplazo mandibular con prótesis personalizada de titanio posterior a la exéresis de ameloblastoma / Mandibular replacement with a customized titanium prosthesis after ameloblastoma excision

Introducción: El ameloblastoma es un tumor odontogénico epitelial benigno con tendencia a la recurrencia local si no se elimina adecuadamente. Las alternativas reconstructivas incluyen el uso de colgajos libres microvascularizados, placas y prótesis personalizada de titanio. Objetivo: Describir un reemplazo hemimandibular con prótesis personalizada de titanio posterior a la exéresis de ameloblastoma. Presentación del caso: Mujer de 44 años de edad, que presentó un hallazgo radiográfico durante la realización de tratamiento pulporradicular del diente número 37. Al realizársele el reconocimiento físico facial mostró aumento de volumen en región geniana izquierda mientras que el examen intrabucal detectó expansión de las corticales en la arcada posteroinferior del mismo lado. Se realizó una radiografía panorámica y tomografía axial computarizada con la que se constató la presencia de imagen radiolúcida, multiloculada, en forma de "pompas de jabón" extendiéndose desde el cuerpo mandibular hasta el cóndilo del lado izquierdo. Se tomó muestra para biopsia, con la cual se constató que se trataba de ameloblastoma con patrón folicular. Se realizó abordaje cervical, segmentaria mandibular con margen de seguridad y exarticulación. Se reemplazó la porción eliminada con prótesis personalizada de titanio. Se mantuvo el chequeo posoperatorio en el que se comprobó una buena evolución. Conclusiones: La cirugía constituyó el pilar de tratamiento utilizado. Una vez realizada la resección quirúrgica se reconstruyó el defecto con prótesis personalizada de titanio, proceder de gran novedad en nuestro medio y útil para restablecer la función y estética(AU)

Introduction: Ameloblastoma is a benign tumor of odontogenic epithelium with a tendency to local recurrence if not removed appropriately. Reconstruction alternatives include the use of microvascularized free flaps, plates and customized titanium prostheses. Objective: Describe a case of mandibular replacement with a customized titanium prosthesis after ameloblastoma excision. Case presentation: A case is presented of a female 44-year-old patient who presented a radiographic finding during pulporadicular treatment of tooth 37. Facial physical examination found an increase in volume in the left genian region, and intraoral observation detected expansion of the corticals in the lower posterior arch of the same side. Panoramic radiography and computed axial tomography showed a multilocular radiolucid image resembling soap bubbles which extended from the mandibular body to the left condyle. A sample was taken for biopsy, which confirmed the diagnosis of follicular pattern ameloblastoma. Segmental mandibular surgery was performed by cervical approach with a safety margin and exarticulation. The portion removed was replaced with a customized titanium prosthesis. Post-operative control showed a good evolution. Conclusions: Surgery was the basic component of the treatment applied. Surgical resection was followed by reconstruction of the defect with a customized titanium prosthesis, a procedure of great novelty in our environment useful to restore function and esthetic appearance(AU)

Osteosíntesis de múltiples fracturas costales desplazadas en un paciente con tórax batiente / Osteosynthesis of multiple displaced costal fractures in a patient with flail chest

El tratamiento de las fracturas costales debe ser individualizado de acuerdo con la severidad de las lesiones y a la magnitud del trauma. El objetivo de esta investigación es presentar un caso donde se utilizaron láminas de titanio, en un paciente con fracturas múltiples de las costillas. Se reporta el caso de un paciente con múltiples fracturas costales de forma lineal y paralelas de los arcos costales con un tórax batiente, que llega al cuerpo de guardia con dolor torácico moderado y disnea. Aunque aún no existe suficiente evidencia científica a favor de los métodos de fijación costal, se realizó la fijación con láminas de titanio logrando la estabilidad de la pared, aliviando el dolor, mejorando la mecánica ventilatoria y logrando su rápida reincorporación a la sociedad(AU)

The treatment of costal fractures should be individualized according to the severity of the injuries and the magnitude of trauma. The objective of this investigation is to present a case where titanium plates were used in a patient with multiple rib fractures. We report the case of a patient with multiple rib fractures of a linear and parallel shape of the costal arches with a swinging thorax, who arrives the emergency room with moderate chest pain and dyspnea. Although there is still not enough scientific evidence that favors the costal fixation methods, the fixation with titanium plates was performed, achieving the stability of the wall, relieving pain, improving the ventilatory mechanics, and achieving the patient's quick reincorporation to the society(AU)

Complications with PMMA compared with other materials used in cranioplasty: a systematic review and meta-analysis

Abstract Polymethyl methacrylate (PMMA) has been considered a suitable material for cranioplasty. However, no consensus has been reached concerning the best material for cranioplasty with regard to minimizing complications. Thus, this systematic review and meta-analysis aimed to compare the complication rates of PMMA with those of autologous bone and titanium mesh. This review was registered with PROSPERO (CRD42016042725). Systematic searches were conducted on PubMed/MEDLINE, Scopus, and Web of Science. The focus question was, "Do PMMA prostheses used in cranioplasty have complications rates similar to those of autologous bone and titanium mesh?" A meta-analysis of complication rates was performed on the basis of dichotomous outcomes assessed by risk ratio (RR) with corresponding 95% confidence intervals (CI). From 1014 data sources, 11 articles were selected according to eligibility criteria. These articles involved 1,256 individuals and 1,278 cranioplasties using autologous bone (n = 408), PMMA (n = 379), or titanium (n = 151). The follow-up period ranged from 63 days to 54.3 months. No difference was observed between the complication rates of PMMA and autologous bone (p = 0.94; RR, 0.98; 95%CI, 0.54-1.75) or between PMMA and titanium (p = 0.38; RR, 1.59; 95%CI, 0.57-4.48). Sub-analysis of the reasons for craniotomy (trauma/non-trauma) was conducted, which revealed no significant difference (p = 0.91; RR, 0.95; 95%CI, 0.37-2.42). The meta-analysis indicated that the use of PMMA yields complication rates that are near those of autologous bone and titanium mesh.

Análise in vivo da modulação óssea em implantes de titânio com superfície em nanoescala / Analysis in vivo of bone modulation in titanium implants with nanoscale surface

Nas últimas décadas houve um aumento considerável na utilização dos implantes metálicos para aplicações na área da ortopedia e odontologia, por isso as pesquisas têm como foco estudar os mecanismos biológicos de interação osso-implante. A nanotopografia de superfície de implantes osseointegráveis apresenta efeito direto sobre a resposta biológica óssea. No entanto a maneira como afeta a osseointegração in vivo ainda não está totalmente elucidada. O objetivo neste estudo foi comparar in vivo a influência da superfície em nanoescala (nano) confeccionada em implantes de titânio comercialmente puro (Ticp), comparado-a a superfície lisa (controle) em modelo experimental de camundongos osterix-mcherry (Osx-mcherry), os quais expressam proteína fluorescente concomitante com a expressão do gene osterix (Osx). Os animais receberam implantes de superfície lisa no fêmur direito e com nanoescala no fêmur esquerdo. Após diferentes períodos de eutanásia baseados na metodologia empregada foram realizados nas peças e nas células os seguintes testes biológicos: microscopia eletrônica de varredura (MEV) para avaliação da adesão celular e da superfície do implante; histologia e nanotomografia (nanoCT) para observação e quantificação de osso neoformado na interface osso/implante; citometria de fluxo para quantificação de células marcadas pelo gene osterix; PCR em tempo real (qPCR) para avaliação da expressão gênica; coloração fosfatase ácida resistente ao tartarato (TRAP) para contagem de osteoclastos. Nossos resultados mostraram que a maioria dos genes estudados estavam superexpressos nas amostras com superfície em nanoescala sendo que alguns deles apresentaram diferenças estatísticas (Teste t, p < 0.05), tais como: Osx (osterix), Alp (fosfatase alcalina), Prx1(homeobox relacionado emparelhado -1), Dmp1 (Dolicol-fosfatase mannosiltransferase subunidade 1), Bsp (sialoproteína óssea) e Ocn (osteocalcina). Os testes estatísticos ANOVA two way seguido do Teste de Tukey quando necessário, foram utilizados para os demais experimentos e o nível de significância foi estabelecido em p < 0.05. Diferenças estatísticas foram encontradas para o nanoCT e histologia entre as superfícies e períodos avaliados e os melhores resultados foram observados para a nanoescala. A coloração TRAP também mostrou diferenças estatísticas entre as superfícies e períodos estudados, com a superfície lisa mostrando melhores resultados aos 3 dias e a nano aos 5 e 7 dias. Não houve diferença estatística para a citometria de fluxo, porém a superfície em nanoescala mostrou melhores resultados que a lisa em todos os períodos analisados. Concluímos que a superfície em nanoescala possui propriedades osteocondutivas e favorece os eventos biológicos que ocorrem na superfície do implante melhorando o processo de osseointegração(AU)

In the last decades there has been a considerable increase in the use of metal implants for applications in the area of orthopedics and dentistry, so the researches are focused on studying the biological mechanisms of bone-implant interaction. Surface nanotopography of osseointegrated implants has a direct effect on the biological response of bone. However the way it affects osseointegration in vivo is not yet fully elucidated. The aim of this study was to compare the in vivo influence of the nanoscale surface (nano) made on implants of commercially pure titanium (Ticp) with the smooth surface (control), using an experimental model of osterix-mcherry mice (Osx-mcherry), which express fluorescent protein concomitant with osterix gene expression (Osx). The animals received implants with smooth surface in the right femur and nanoscale in the left femur. After different periods of euthanasia based on the methodology used, biological tests were performed in the femur and cells: scanning electron microscopy (SEM) for evaluation of cell adhesion and implant surface; histology and nanotomography (NanoCT) for observation and quantification of neoformed bone at implant interface; flow cytometry for quantification of cells marked by the osterix gene; Real-time PCR (qRT-PCR) for gene expression evaluation; tartrate resistant acid phosphatase staining (TRAP) for osteoclast counts. Our results showed that most genes studied were overexpressed in the nanoscale surface and some of which presented statistical differences(t Test, p <0.05), such as: Osx (osterix), Alp (alkaline phosphatase), Prx1 (related paired homeobox), Dmp1 (Dolicol-phosphatase mannosyltransferase subunit 1), Bsp (bone sialoprotein) and Ocn (osteocalcin). The two-way ANOVA statistical test followed by the Tukey test when necessary were used for the other experiments and the level of significance was set at p <0.05. Statistical differences were found for the nanoCT and histology between surface and periods evaluated and the best results were observed for the nanoscale. The TRAP staining also showed statistical differences between the surfaces and periods studied, with the smooth surface showing better results at 3 days and nano at 5 and 7 days. There was no statistical difference for flow cytometry, but the nanoscale surface showed better results than the smooth surface in all analyzed periods. We conclude that the nanoscale surface has osteoconductive properties and improves the biological events that occur on implants surface improving the osseointegration process(AU)

Efeito de partículas metálicas liberadas dos implantes dentários sobre os tecidos peri-implantares / The effect of metallic particles released from dental implants on peri-implant tissues

Objetivo: realizar uma revisão da literatura sobre os efeitos das partículas metálicas liberadas nos tecidos peri-implantares, como consequência do uso de técnicas terapêuticas empregadas no tratamento de doenças peri-implantares e/ou pela degradação do implante. Material e métodos: foi efetuado um levantamento bibliográfico através de pesquisas em livros, textos e base de dados PubMed entre o período de 1977 a 2015. Os seguintes termos foram explorados: "titanium wear e dental implant", "titanium corrosion e dental implant", "bio-tribocorrosion", "peri-implantitis", "treatment of peri-implantitis", "titanium particles release e dental implant", "titanium ion release e dental implant", e "tratamento da peri-implantite". Foram selecionados 91 artigos científicos, definidos como os mais relevantes sobre o tema. Resultados: há liberação de citocinas pró-inflamatórias, infiltrado de células de resposta inflamatória e ativação dos osteoclastos nos tecidos peri-implantares, em contato com partículas e íons metálicos. Ainda, foram reportadas alterações degenerativas em macrófagos, e neutrófilos que fagocitaram micropartículas de titânio, bem como mutações em células humanas em cultura contendo nanopartículas de TiO2. Conclusão: partículas metálicas liberadas a partir do sistema de implantes têm potencial citotóxico e genotóxico, e são capazes de induzir resposta inflamatória nos tecidos peri-implantares.

Objective: to review the literature regarding the effect of metallic particles released at the peri-implant tissues, as a consequence of therapeutic techniques to treat peri-implant diseases and/or by implant degradation. Material and methods: a search was made at the PubMed from 1977 to 2015. The following terms were combined: titanium wear and dental implant", "titanium corrosion and dental implant", "bio-tribocorrosion", "peri-implantitis", "treatment of peri-implantitis", "titanium particles release and dental implant", "titanium ion release and dental implant", and "peri-implant treatment". 91 scientific articles were selected to define the most relevant topics. Results: there is pro-infl ammatory cytokine release, inflammatory cell infiltrate and osteoclast activation over the peri-implant tissues contacting particles and metallic ions. Also, degenerative changes on macrophages and neutrophils engulfing titanium microparticles were reported, as well as mutations on culture human cells containing TiO2 nanoparticles. Conclusion: metallic particles released from the dental implant system can be cytotoxic and genotoxic in nature and to induce inflammatory response at the peri-implant tissues.

Adenovirus-mediated siRNA targeting TNF-α and overexpression of bone morphogenetic protein-2 promotes early osteoblast differentiation on a cell model of Ti particle-induced inflammatory response in vitro

Wear particles are phagocytosed by macrophages and other inflammatory cells, resulting in cellular activation and release of proinflammatory factors, which cause periprosthetic osteolysis and subsequent aseptic loosening, the most common causes of total joint arthroplasty failure. During this pathological process, tumor necrosis factor-alpha (TNF-α) plays an important role in wear-particle-induced osteolysis. In this study, recombination adenovirus (Ad) vectors carrying both target genes [TNF-α small interfering RNA (TNF-α-siRNA) and bone morphogenetic protein 2 (BMP-2)] were synthesized and transfected into RAW264.7 macrophages and pro-osteoblastic MC3T3-E1 cells, respectively. The target gene BMP-2, expressed on pro-osteoblastic MC3T3-E1 cells and silenced by the TNF-α gene on cells, was treated with titanium (Ti) particles that were assessed by real-time PCR and Western blot. We showed that recombinant adenovirus (Ad-siTNFα-BMP-2) can induce osteoblast differentiation when treated with conditioned medium (CM) containing RAW264.7 macrophages challenged with a combination of Ti particles and Ad-siTNFα-BMP-2 (Ti-ad CM) assessed by alkaline phosphatase activity. The receptor activator of nuclear factor-κB ligand was downregulated in pro-osteoblastic MC3T3-E1 cells treated with Ti-ad CM in comparison with conditioned medium of RAW264.7 macrophages challenged with Ti particles (Ti CM). We suggest that Ad-siTNFα-BMP-2 induced osteoblast differentiation and inhibited osteoclastogenesis on a cell model of a Ti particle-induced inflammatory response, which may provide a novel approach for the treatment of periprosthetic osteolysis.

Comparing coronal discoloration between AH26 and ZOE sealers

Intrinsic tooth discolorations after endodontic treatment are principally attributed to the composition of necrotic pulp tissue, hemorrhage within the pulp cavity, endodontic medicaments and/or filling materials. Residual sealer left in pulp chamber after obturation can cause discoloration. The objective of this in vitro study was to evaluate coronal discoloration created by AH26 and ZOE sealers after four months. Fifty intact human extracted maxillary central incisors were employed. Access cavities were prepared in all samples and root canals were instrumented; coronal orifices were then sealed using self-cure glass ionomer. The teeth were divided into two experimental groups [n=20] according to utilized sealer in pulp chambers including AH26 and Dorifill [ZOE]. The remaining 10 teeth served as negative and positive controls [n=5]. The access cavities were sealed with self-cure glass ionomer. Teeth were kept in incubator for four month. Preliminary digital images of the teeth were taken and then compared with those related to 4-month follow-up. The images were assessed using Photoshop software. Data was analyzed using paired t-test and independent samples t-test. The teeth which were filled with AH26 sealer showed significantly greater discoloration than those filled with ZOE sealer [Dorifill] [P<0.05]. AH26 sealer causes greater discoloration of the crown compared to ZOE sealer. Despite the other disadvantage of AH26 sealer, it seems that Dorifill is more esthetically considerate

Inhibitory effect of (-)-epigallocatechin gallate on titanium particle-induced TNF-alpha release and in vivo osteolysis

Tumor necrosis factor-alpha (TNF-alpha) and inflammatory cytokines released from activated macrophages in response to particulate debris greatly impact periprosthetic bone loss and consequent implant failure. In the present study, we found that a major polyphenolic component of green tea, (-)-epigallocatechin gallate (EGCG), inhibited Ti particle-induced TNF-alpha release in macrophages in vitro and calvarial osteolysis in vivo. The Ti stimulation of macrophages released TNF-alpha in a dose- and time-dependent manner, and EGCG substantially suppressed Ti particle-induced TNF-alpha release. Analysis of signaling pathway showed that EGCG inhibited the Ti-induced c-Jun N-terminus kinase (JNK) activation and inhibitory kappaB (IkappaB) degradation, and consequently the Ti-induced transcriptional activation of AP-1 and NF-kappaB. In a mouse calvarial osteolysis model, EGCG inhibited Ti particle-induced osteolysis in vivo by suppressing TNF-alpha expression and osteoclast formation. Therefore, EGCG may be a potential candidate compound for osteolysis prevention and treatment as well as aseptic loosening after total replacement arthroplasty.

Comparative effects of copper, iron, vanadium and titanium on low density lipoprotein oxidation in vitro

Oxidation of low density lipoprotein [LDL] has been strongly implicated in the phathogenesis of atherosclerosis. The use of oxidants in dietary food stuff may lead to the production of oxidized LDL and may increase both the development and the progression of atherosclerosis. The present work investigated the effects of some elements including: copper [Cu], iron [Fe], vanadium [V] and titanium [Ti] on in vitro LDL oxidation quantitatively. The first LDL fraction was isolated from fresh plasma by single vertical discontinuous density gradient ultracentrifugation. The formation of conjugated dienes and thiobarbituric acid reactive substances and increase in electrophoretic mobility of LDL were monitored as markers of the oxidation of LDL. It was demonstrated that Cu, Fe, V and Ti exhibited strong oxidant activity in this respect [P<0.001]. Oxidation of LDL in the presence of Cu was more and appeared to be in this order Cu>Fe> V>Ti. Discussion: Cu, Fe, V and Ti are redox-active transition metals that may cause oxidative damage to lipids, proteins and DNA molecules. We suggest that these elements may also influence the oxidation of LDL in vivo, which could increase both the development and progression of atherosclerosis

Cytotoxicity of yellow sand in lung epithelial cells.

The present study was carried out to observe the cytotoxicity of yellow sand in comparison with silica and titanium dioxide in a rat alveolar type II cell line (RLE-6TN). Yellow sand (China Loess) was obtained from the loess layer in the Gunsu Province of China. The mean particle diameter of yellow sand was about 0.003 +/- 0.001 mm. Major elements of yellow sand were Si(27.7 +/- 0.6%), Al(6.01 +/- 0.17%), and Ca(5.83 +/- 0.23%) in that order. Silica and yellow sand significantly decreased cell viability and increased [Ca2+]i. All three particles increased the generation of H2O2. TiO2 did not change Fenton activity, while silica induced a slight increase of Fenton activity. In contrast, yellow sand induced a significant increase of Fenton activity. Silica, yellow sand and TiO2 induced significant nitrite formations in RLE-6TN cells. Silica showed the highest increase in nitrite formation, while yellow sand induced the least formation of nitrite. Silica and yellow sand increased the release of TNF-a. Based on these results, we suggest that yellow sand can induce cytotoxicity in RLE-6TN cells and reactive oxygen species, Fenton activity and reactive nitrogen species might be involved in this toxicity.

Estudo da interação entre células endoteliais humanas e biomateriais utilizados em cirurgia buco-maxilo-facial / Interaction of human endothelial cells with biomaterials applied on maxillo-facial surgery

Neste estudo procuramos analisar a interação entre células endoteliais humanas e biomateriais utilizados em cirurgia oral, através de análises histológicas e ensaios imunocitoquímicos. Culturas primárias foram isoladas de veias de cordões umbilicais humanos. As células foram semeadas, em densidade determinada, sobre secções circulares de membrana colágena, placas de titânio e controles; foram mantidas por 1, 7 ou 14 dias. As células proliferaram, atingiram confluência e após 14 dias formaram camada plana e uniforme. Os resultados demonstraram que os materiais estudados permitem a proliferação e a adesão das células endoteliais. Esta adesão é mediada pela interação de integrinas e proteínas.With the present investigation, we examined the behavior of endothelial cells on two different biomaterials, using histological and immunocitochemical methods. The endothelial cells were isolated from umbilical cord veins. Cells, after two passages, were seeded in a standard density on a collagen membrane, on commercially pure titanium in the form of plates and on control surfaces. Then these were maintained for 1, 7 or 14 days. After 14 days, we could observe a confluent monolayer of cells. Our results showed that both studied materials support endothelial cells growth and attachment and this is most related to the binding through integrins and proteins...

L'allergie au titane et les implants dentaires : prevention et traitement

Les cas rapportes dans la litterature ont montre une relation etroite entre les implants en titane et l'apparition de l'allergie. Pour pallier a ce probleme les medecins dentistes; doivent etablir un interrogatoire minutieux et un examen clinique complet pour determiner les patients a risques. Ces derniers devraient subir des tests cutanes ou biologiques afin de prevenir cette allergie. Par ailleurs; en presence de diagnostic positif a l'allergie au titane; les implants devraient etre retires et remplaces par d'autres implants en un materiau alternatif

L'allergie au titane et les implants dentaires : Facteurs de risque

Le titane est actuellement le materiau de choix en implantologie orale. Connu pour son excellente biocompatibilite; un grand nombre de professionnels de sante pensent qu'il ne serait pas responsable de reaction d'hypersensibilite.Neanmoins; il apparait dans de recentes etudes que le titane peut donner lieu a une toxicite et a des reactions allergiques immediates ou retardees ce qui pourrait expliquer les echecs successifs d'implants dentaires qui surviennent chez certains patients

Histological evaluation of the calcitonin effects on bone healing following titanium implant insertion / Avaliaçäo histológica dos efeitos da calcitonina na reparaçäo óssea após a colocaçäo de implante de titânio

O objetivo deste estudo foi foi

Análise da proliferaçäo endosteal após a colocaçäo de "discos" de titânio c.p. em coelhos, tratados por diferentes formas / Analysis of the endosseus proliferation after the titanium c.p. \"discs\" implantation in rabbits, by different treatments

Recentemente, tem tornado aparente que o sucesso do implante endosteal é largamente, se näo totalmente, determinado pela biocompatibilidade do material usado. Esta biocompatibilidade parece estar determinada näo somente pela natureza química do material, mas também pela propriedade micromorfológica da superfície do implante. Os resultados apresentam uma avaliaçäo histológica da cicatrizaçäo inicial da implantaçäo de discos de titânio c.p. com superfície porosa fixados endostealmente. Para testar esta avaliaçäo foram utilizados 12 coelhos machos com peso médio de 3,2 Kg., sendo que cada animal recebeu 2 discos de titânio c.p.. Em todos os animais, os discos de titânio foram utilizados para avaliaçäo histológica de crescimento ósseo...

Caracterizaçäo de superfícies de Titânio cp grau I após diferentes tratamentos / Characterization of cp Titanium surfaces after different treatments

A natureza de superfície de um biomaterial determina os processos envolvidos na resposta biológica a um material implantado e pode ser descrita em termos de energia, química e morfologia superficial. O objetivo desta pesquisa foi analisar os efeitos de diferentes tratamentos preparatórios sobre as superfícies de Ti cp grau I utilizado na fabricaçäo de implantes odontológicos. Esta pesquisa faz parte de um projeto multidisciplinar cujo principal objetivo a longo prazo é definir as características superficiais que determinam uma interaçäo biológica ótima com implantes de Ti cp. Noventa discos de Ti cp grau I foram preparados metalograficamente com papel SiC de granulaçäo 200 e 600, polidos utilizando pontas de diamante de 6,3 e 1/4µ e submetidos a um protocolo de limpeza através de solventes e lavagens com água bidestilada e deionizada...