<p>Efforts to create a reliable, long–term implantable glucose sensor have been stymied by the effects of the foreign body response and wound healing that introduce delayed response times as well as unpredictable sensor performance. Loss of vascularization from fibrotic encapsulation around implanted sensors is purported as a key contributor to sensor failure, as glucose and oxygen transport to the sensor becomes impeded. Improving sensor performance by increasing angiogenesis and/or reducing capsule thickness using tissue-modifying textured coatings is attractive because texturing is not dependent upon a depletable drug reservoir. A significant range of materials and pore sizes are capable of promoting angiogenesis and reducing capsule thickness, provided pores have open-architecture with dimensions sufficiently large enough to allow inflammatory cell infiltration. </p><p><br></p><p>Poly–L–lactic acid was gas foamed/salt leached with ammonium bicarbonate to produce porous coatings for Medtronic MiniMed SOF–sensor glucose sensors. Coating properties included 30μm pore diameters, 90% porosity, and 50μm wall thickness. Cytotoxicity, degradation, and sensor response time studies were performed to ensure the porous coatings were non–toxic and negligibly retarded glucose diffusion prior to <italic>in vivo</italic> testing. Histology was used to evaluate angiogenesis and collagen deposition adjacent to porous coated and bare (i.e. smooth, uncoated) non–functional sensor strips after three weeks in the rat dorsal subcutis. Functional Medtronic glucose sensors, with and without porous coatings, were percutaneously implanted in the rat dorsum to assess if the angiogenic–inducing properties observed around the non–functional porous coated sensor strips translated into stable, non–attenuated sensor signals over two and three weeks. MiniLink<super>TM </super>transmitters were attached to the rats, permitting continuous glucose monitoring. Vessel counts and collagen deposition adjacent to sensors were determined from histological analysis. A one–sided dorsal window model was developed to further evaluate the interplay between vascularization and sensor performance Sensors were inserted beneath the windows, allowing visualization of microvascular changes adjacent to sensor surfaces, with simultaneous evaluation of how vascular changes impacted interstitial glucose monitoring. </p><p><br></p><p>Porous coating did have angiogenic–inducing effects on the surrounding tissue. When fully implanted in the rat dorsum, sensor strips with porous coatings induced three–fold more vessels within 100μm<super>2</super> of the sensor strip surface after three weeks and two-fold more cumulative vessel lengths within 1mm<super>2</super> after two weeks, compared to bare surfaces. In contrast, when percutaneously implanted in the rat dorsum, porous coated and bare sensors were equally highly vascularized, with two–fold more vessels than fully implanted bare sensors. </p><p><br></p><p>Despite increased angiogenesis adjacent to percutaneous sensors, sensor signal attenuation occurred over 14 days, suggesting that angiogenesis plays a secondary role in maintaining sensor function. Percutaneously implanted porous coated sensors had greater reductions in baseline current (20 to 50+%) over two weeks than bare sensors (10 to 30%). Mechanical stresses imposed by percutaneous tethering may override the beneficial effects of porous coatings. Furthermore, integration of the porous coating with the surrounding tissue may have increased tissue tearing at the porous coating–tissue, increasing inflammation and collagen deposition resulting in greater signal attenuation compared with bare sensors. Future investigations of the role mechanical irritation has on wound healing around percutaneous glucose sensors are warranted.</p> / Dissertation

Head injuries are a major health concern for sport participants as 90% of emergency department visits for sport-related brain injuries are concussion related (Canadian Institute for Health Information, 2016). Recently, reports have shown a higher incidence of sport-related concussion in female athletes compared to males (Agel et al., 2007). Few studies have described the events by which concussions occur in women’s hockey (Delaney et al., 2014, Brainard et al., 2012; Wilcox et al., 2014), however a biomechanical analysis of the risk of concussion has not yet been conducted. Therefore, the purpose of this study was to identify the riskiest concussive events in elite women’s hockey and characterize these events through reconstructions to identify the associated levels of peak linear and angular acceleration and strain from finite element analysis. 44 head impact events were gathered from elite women’s hockey game video and analyzed for impact event, location and velocity. In total, 27 distinct events based on impact event, location and velocity were reconstructed using a hybrid III headform and various testing setups to obtain dynamic response and brain tissue response. A three-way Multivariate Analysis of Variance (MANOVA) was conducted to determine the influence of event, location and velocity. The results of this study show that head-to-ice impacts resulted in significantly higher responses compared to shoulder-to-head collisions and head-to boards impacts however, shoulder and boards impacts were more frequent. All events produced responses comparable to proposed concussion threshold values (Zhang et al., 2004). This research demonstrates the importance of considering the event, the impact characteristics, the magnitude of response, and the frequency of these impacts when attempting to capture the short and long term risks of brain trauma in women’s hockey.

O Cimento de Ionômero de Vidro (CIV) é um material restaurador utilizado na Odontologia Minimamente Invasiva pois, além de apresentar propriedade adesiva à estrutura dental, apresenta propriedades tais como liberação e absorção de íons flúor, compatibilidade biológica com os tecidos bucais e coeficiente de expansão térmica similar ao da dentina. No entanto, o CIV apresenta baixa resistência mecânica, alta suscetibilidade à perda e ao ganho de água nas primeiras 24 horas (sinérese e embebição), período prolongado de presa e polimento ruim. Apesar desse material ter sido introduzido na Odontologia há mais de 40 anos, sua fórmula original vem sofrendo alterações, com o objetivo principal de aprimorar as propriedades mecânicas e alcançar melhores resultados clínicos. Dentre os CIV convencionais, destaca-se o EQUIA&reg; Forte Fil (GC Corporation, Tokyo, Japan), material elaborado com o objetivo de aprimorar as características físicas e estéticas do seu antecessor EQUIA&reg; Fil. No entanto, até o momento não existem trabalhos biológicos avaliando o desempenho do EQUIA&trade; Forte e Ketac&trade; Universal Aplicap&trade;. O objetivo deste estudo foi avaliar a resposta do tecido conjuntivo subcutâneo de camundongos isogênicos após implante de diferentes cimentos de ionômero de vidro (EQUIA&reg; Forte Fil, EQUIA&reg; Fil e Ketac&trade; Universal Aplicap&trade;). Foram utilizados 87 camundongos isogênicos da linhagem BALB/c divididos em 12 grupos, sendo 9 experimentais (Ketac, E. Fil e E. Forte nos períodos de 7, 21 e 63 dias) e 3 controles (tubos de polietileno vazios, nos mesmos períodos). Decorridos os períodos experimentais, a porção do tecido conjuntivo subcutâneo circundante ao material implantado foi removida e submetida ao processamento histotécnico e à coloração com hematoxilina e eosina. Foi realizada a descrição da reação tecidual em contato com cada material, análise semi-quantitativa do fibrosamento e do infiltrado inflamatório e análise quantitativa da espessura do tecido reacional granulomatoso em contato com o material testado ou tubo de polietileno. Os dados foram analizados estatisticamente (&alpha;=0,05), utilizando o teste de Kruskal-Wallis, seguido pelo Pós-teste de Dunn. Inicialmente, o fibrosamento não foi diferente entre os materiais testados (p>0,05), porém passou a ser diferente aos 21 dias, com o controle apresentando o estágio mais avançado de fibrosamento, e chegando ao final do experimento com o Grupo EQUIA&reg; Forte Fil com estágio mais avançado de fibrosamento, em comparação ao grupo EQUIA&reg; Fil (p<0,05). O infiltrado inflamatório, por sua vez, não apresentou diferença entre os materiais testados ao longo dos períodos experimentais (p>0,05). A área do tecido reacional granulomatoso foi maior para o Grupo E. Forte, diferindo do controle em todos os períodos avaliados (p<0,05). De acordo com os resultados obtidos, concluiu-se que todos os cimentos à base de ionômero de vidro testados apresentaram compatibilidade tecidual, de acordo com os diferentes parâmetros avaliados / The Glass Ionomer Cement (GIC) is a restorative material used in Minimally Invasive Dentistry. Besides it presenting adhesive properties to the dental structure, GIC has properties such as release and absorption of fluoride ion, biological compatibility with buccal tissues and expansion coefficient similar to that of dentin. However, GIC presents low mechanical resistance, high susceptibility to loss and water gain in the first 24 hours (syneresis and imbibition), prolonged setting time and poor polishing. Although this material was introduced in Dentistry more than 40 years ago, its original formula has undergone changes, with the main objective of improving the mechanical properties and achieving better clinical results. Among the conventional GIC, we highlight EQUIA&reg; Forte Fil, a material developed with the aim of improving the physical and aesthetic characteristics of its predecessor EQUIA&reg; Fil. However, there are no biologic researches evaluating the performance of EQUIA&reg; Forte and Ketac&trade; Universal Aplicap&trade;. The aim of this study was to evaluate the subcutaneous connective tissue response of isogenic mice after implanting different glass ionomer cements (EQUIA&reg; Forte Fil, EQUIA&reg; Fil and Ketac&trade; Universal Aplicap&trade;). Eighty-seven isogenic mice of the BALB/c were divided into 12 groups, 9 were experimental (Ketac, E. Fil and E. Forte at 7, 21 and 63 days) and 3 controls (empty polyethylene tubes at the same experimental time). After the experimental periods, the portion of the subcutaneous connective tissue surrounding the implanted material was removed and subjected to histotechnical processing and staining with hematoxylin and eosin. A description of the tissue reaction in contact with each material, semi-quantitative analysis of f collagen fiber formation and inflammatory infiltrate and quantitative analysis of the tissue thickness of the granulomatous reaction tissue in contact with the tested material or polyethylene tube were performed. Data were analyzed statistically (&alpha;=0.05) using the Kruskal-Wallis test, followed by the Dunn Post test. Initially, the collagen fiber formation was not different between the tested materials (p>0.05), but it became different at 21 days, with the control presenting the most advanced stage of collagen fiber formation, and reaching the end of the experiment with the EQUIA&reg; Forte Fil group with a more advanced stage of collagen fiber formation, compared to the EQUIA&reg; Fil group (p<0.05). Inflammatory infiltrate, on the other hand, showed no difference between the materials tested during the experimental periods (p>0.05). The tissue thickness was larger for the EQUIA&reg; Forte Fil group, differing from the control group in all evaluated periods (p<0.05). According to the results obtained, it was concluded that all the glass ionomer - based cements tested showed tissue compatibility, according to the different parameters evaluated

O presente estudo teve como objetivo avaliar in vivo a capacidade de selamento de três materiais obturadores constituídos de cimentos endodônticos resinosos, sendo dois (AH Plus e EndoRez) associados a cones de guta-percha, e um (Real Seal) a cones de Resilon, em pré-molares de cães, expostos ao meio bucal, após o preparo para colocação de pino protético. Objetivou, também, avaliar a correlação entre a situação inflamatória dos tecidos periapicais e a infiltração microbiana. Para tal, foi realizado o preparo químico-mecânico de 80 dentes (160 canais), sendo dez (20 canais) em cada cão. Antes da obturação, os canais foram distribuídos, aleatoriamente, em sete grupos. Nos grupos I – GI (n=32) e controle negativo I – C-I (n=16), os canais foram obturados com cones de guta-percha e AH Plus; nos grupos II – GII (n=32) e controle negativo II – C-II (n=16), com cones de guta-percha e EndoRez; e nos grupos III – GIII (n=32) e controle negativo III – C-III (n=16), com cones de Resilon e Real Seal. Os canais do grupo controle positivo – C+ (n=16) não foram obturados. Imediatamente após a obturação, realizou-se a desobturação parcial dos canais, restando 4 mm de material na região apical. Os dentes foram selados, provisoriamente, com amálgama de prata, durante 72 horas. Após esse período, o selamento coronário de todos os canais, com exceção dos pertencentes aos grupos C-, foi removido, ficando expostos ao meio bucal por 90 dias. Os animais foram mortos, e as mandíbulas e maxilas removidas e seccionadas, separando-se o lado esquerdo do direito. Nos dentes das hemi-arcadas do lado esquerdo, o selamento dos canais dos grupos C- foi removido e o espaço protético irrigado, abundantemente, com água destilada. Após, foram secos e preenchidos com tinta nanquim. Os dentes foram, novamente, selados e, passadas 96 horas, extraídos. A seguir, as raízes foram separadas, armazenadas em tubos de ensaio e diafanizadas. Os espécimes do lado direito foram processados histologicamente, empregando-se as colorações de Hematoxilina e Eosina de Harris (HE) e Brown e Brenn (BB). A infiltração de corante foi medida com auxílio de lupa esteroscópica, com aumento de 10x. A análise dos cortes histológicos foi realizada em microscópio óptico, classificando-se o estado inflamatório dos tecidos periapicais e a infiltração microbiana em escores de 1 a 4. Os resultados da infiltração de corante evidenciaram que todos os grupos apresentaram menor infiltração que o grupo C+ (p<0,001) e que os grupos GI, GII e GIII não diferiram significativamente (P>0,05). O grupo GII apresentou diferenças significativas em relação ao seu grupo controle negativo, mostrando maior infiltração de corante (P<0,001). Na análise histológica, todos os materiais testados apresentaram menor grau de reação inflamatória e de infiltração microbiana, quando comparados com o grupo C+ (P≤0,001). Além disso, não foram observadas diferenças significativas entre os grupos GI, GII e GIII, bem como destes com seus respectivos controles (P>0,05). O teste de correlação de Spearman mostrou uma forte correlação entre resposta inflamatória e infiltração microbiana (rs= 0,57; P<0,001). A partir do exposto, concluiu-se que os materiais testados não apresentaram diferenças significativas entre si e que a resposta inflamatória periapical apresentou correlação direta com a infiltração coronária microbiana. / The aim of this study was to assess in vivo the sealing ability of three resin-containing endodontic sealers, two associated with gutta-percha points (AH Plus and EndoRez) and one associated with Resilon points (RealSeal). Mongrel dogs had their premolars prepared and filled, then post-prepared, which space became exposed to the oral environment. The correlation between inflammatory condition and level of microbial leakage was also tested. For that purpose, 80 teeth (160 root canals), being 10 (20 root canals), for each dog, were chemo-mechanically prepared and randomly divided into the following groups: GI (n=32) and C-I (negative control; n=16): root filling with gutta-percha and AH-Plus; GII (n=32) and C-II (n=16): root filling with gutta-percha and Endorez; GIII (n=32) and C-III (n=16): root filling with Resilon and RealSeal; C+ (positive control; n=16): no root filling. Immediately following filling procedures, post space preparation was done leaving 4mm of filling material apically. Teeth had their crowns provisionally sealed with amalgam for 72 hours. Then, coronal seal was removed (except for C-) and remained exposed to the oral environment for 90 days. The dogs were sacrificed and their mandible and maxilla were removed and sectioned, separating right and left sides. In the specimens from the left side, the C- teeth had their seal removed, and all teeth had their post space irrigated with distilled water, then filled with India ink. Following 96 hours, the teeth were extracted. Roots were labeled as to the groups and subjected to clearing process in test tubes. The specimens from the right side were histologically processed and stained with Hematoxicilin and Eosin (HE) and Brown and Brenn (BB). The ink leakage was measured three dimensionally under stereoscope microscopy (10x). Histological sections were assessed under light microscopy by a senior observer blinded as to the groups and the inflammatory state was classified using scores varying from 1 to 4 in an ascending severity. The same severity scoring applied to the microbial leakage, being the severity scored as to the depth of microbial penetration within the dentinal tubules. The results showed that all the test groups displayed less leakage than C+ group (P<0,001). GI, GII and GIII did not differ statistically amongst them. Sealing ability of GII differed significantly to its control group – C-II (P<0,001).Histological analysis showed that all test groups displayed lower inflammatory reaction and microbial leakage when compared to C+ group (P≤0,001). No significant differences were found amongst GI, GII and GIII and their respective controls (p>0,05). Spearman correlation test showed a strong correlation between inflammatory response and microbial leakage (rs= 0,57; P<0,001). It could be concluded that the tested materials did not differ amongst themselves and that the periapical tissue response correlated directly with the microbial coronal leakage.

Made available in DSpace on 2016-08-17T18:39:42Z (GMT). No. of bitstreams: 1 4169.pdf: 1866763 bytes, checksum: 38d468ca7232537d6952ee24e68d0593 (MD5) Previous issue date: 2011-08-29 / Universidade Federal de Minas Gerais / Due to limited availability of autogenous bone and of the risks associated with the use of bone allografts, new synthetic materials have been developed in order to replace the bone tissue lost due to trauma or pathological process. The bioactive materials in the form of scaffolds are synthetic materials promising for bone grafting. Several studies suggest that these biomaterials are able to stimulate the proliferation of osteoblasts and osteogenesis at the site of fracture. However, the feasibility of these biomaterials to a clinical application requires the investigation of their biocompatibility. In this context, this study aimed to evaluate the biocompatibility of a scaffold synthesized from a fully crystallized glass-ceramic bioactive quaternary system P2O5-Na2O-CaO-SiO2 (Biosilicate®), through histopathological analysis of the biomaterial implanted in the subcutaneous tissue of rats and the cytotoxicity and genotoxicity analysis of the biomaterial in cell cultures (OSTEO-1 and L929 cells). Histopathologic analysis of the biomaterial was performed using 65 Wistar rats male (210- 260 g), randomly divided into two groups, Control group (n = 3 animals per period) and Biosilicate group (n = 10 animals per period), evaluated at 7, 15, 30, 45 and 60 days after surgery. The animals of Biosilicate group underwent surgery and received a subcutaneous implant of Biosilicate® scaffolds. The animals of Control group underwent surgery but did not receive any biomaterial implant. The cytotoxicity analysis was performed to assess the effect of products leaching from Biosilicate® scaffolds (extracts) on cellular proliferation (MTT). The extracts were evaluated in various concentrations (100, 50, 25 and 12.5%) in experimental periods of 24, 72 and 120 hours in two cell lines (OSTEO-1 and L929). The genotoxicity analysis (comet assay) was performed to assess DNA damage in cells OSTEO-1 and L929 grown in contact with the Biosilicate® scaffolds in different periods of 24, 72 and 96 horas. The statistical analysis of parametrics data was performed by analysis of variance (ANOVA) followed by Tukey post-hoc and the analysis of nonparametrics data was performed by Mann-Whitney test. Both statistical tests were performed with a significance level of 5%. The results of histopathological analysis showed that the animals of the Control group did not present inflammation process, necrotic tissue and fibrous tissue. The animals of Biosilicato group showed a granulation tissue after 7 days of implantation. In the other periods (15, 30, 45 and 60 days) a chronic inflammation process of foreign body, marked by the presence of fibrous tissue and giant cells was observed. No infection or necrotic tissue was observed in any animal. In the analysis of cytotoxicity, it was observed that extracts of Biosilicato® scaffolds did not have any significant effect in reducing cell proliferation OSTEO-1 and L929, and that lower concentrations of the extracts (12.5 and 25%) stimulated the proliferation of both cells in periods of 72 and 120 hours. The analysis of genotoxicity showed that the Biosilicate® scaffolds did not induce DNA damage in the cell lines tested in all experimental periods. The results of this study showed that the Biosilicate® scaffolds presented biocompatibility in vivo and in vitro. / Devido a limitada disponibilidade de osso autógeno e dos riscos associados ao uso de osso alógeno, novos materiais sintéticos vêm sendo desenvolvidos com o objetivo de substituir o tecido ósseo perdido em decorrência de traumatismos ou processos patológicos. Os materiais bioativos na forma de scaffolds são materiais sintéticos promissores para enxertia óssea. Vários estudos sugerem que estes biomateriais são capazes de estimular a proliferação de osteoblastos e a osteogênese no local da fratura. No entanto, a viabilização destes biomateriais a uma aplicação clínica requer o emprego de testes que avaliem a sua biocompatibilidade. Dentro deste contexto, o presente estudo teve como objetivo avaliar a biocompatibilidade do scaffold sintetizado a partir de uma vitrocerâmica bioativa totalmente cristalizada do sistema quaternário P2O5-Na2O-CaO-SiO2 (Biosilicato®), por meio da análise histopatológica do biomaterial implantado no tecido subcutâneo de ratos, e pelas análises de citotoxicidade e genotoxicidade do biomaterial em cultura de células da linhagem OSTEO-1 e L929. A análise histopatológica do biomaterial foi realizada utilizando 65 ratos machos da linhagem Wistar (210-260 g), distribuídos aleatoriamente em dois grupos, Controle (n = 3 animais por período) e Biosilicato (n = 10 animais por período), avaliados em períodos distintos de 7, 15, 30, 45 e 60 dias. Os animais do grupo Biosilicato foram submetidos a uma cirurgia no tecido subcutâneo e receberam um implante de scaffold de Biosilicato®. Os animais do grupo Controle foram submetidos à mesma cirurgia, mas não receberam o implante do biomaterial. A análise de citotoxicidade foi realizada para avaliar os efeitos dos produtos da lixiviação dos scaffolds de Biosilicato® (extratos) na proliferação celular pelo ensaio MTT. Os extratos foram avaliados em várias concentrações (100, 50, 25 e 12,5%) em períodos experimentais de 24, 72 e 120 horas, utilizando duas linhagens celulares (OSTEO-1 e L929). A análise de genotoxicidade (ensaio cometa) foi realizada para avaliar os danos no DNA de células OSTEO-1 e L929 cultivadas em contato com scaffolds de Biosilicato® em períodos distintos de 24, 72 e 96 horas. A análise estatística dos dados paramétricos foi realizada pelo teste de variância (ANOVA), seguido do post-hoc de Tukey, e a análise dos dados não paramétricos foi realizada pelo teste de Mann-Whitney. Ambos os testes estatísticos foram realizados com nível de significância de 5%. Os resultados da análise histopatológica demonstraram que os animais do grupo Controle não apresentaram processo inflamatório, tecido necrótico ou tecido fibroso. Já os animais do grupo Biosilicato apresentaram um tecido de granulação após 7 dias de implantação e nos demais períodos (15, 30, 45 e 60 dias) apresentaram um processo inflamatório crônico de corpo estranho, marcado pela presença de tecido fibroso e células gigantes multinucleadas. Em todos os animais avaliados não foi evidenciado foco de infecção ou tecido necrótico. Na análise de citotoxicidade foi observado que os extratos dos scaffolds de Biosilicato® não possuem efeito significativo na redução da proliferação de células OSTEO-1 e L929, e que as menores concentrações dos extratos (12,5 e 25%) estimularam a proliferação de ambas às células nos períodos de 72 e 120 horas. Na análise de genotoxicidade foi evidenciado que os scaffolds de Biosilicato® não induzem danos do DNA de células de ambas às linhagens testadas em todos os períodos experimentais. Os resultados obtidos neste estudo demonstraram que os scaffolds de Biosilicato® apresentaram biocompatibilidade em experimentos in vivo e in vitro.

O presente estudo teve como objetivo avaliar in vivo a capacidade de selamento de três materiais obturadores constituídos de cimentos endodônticos resinosos, sendo dois (AH Plus e EndoRez) associados a cones de guta-percha, e um (Real Seal) a cones de Resilon, em pré-molares de cães, expostos ao meio bucal, após o preparo para colocação de pino protético. Objetivou, também, avaliar a correlação entre a situação inflamatória dos tecidos periapicais e a infiltração microbiana. Para tal, foi realizado o preparo químico-mecânico de 80 dentes (160 canais), sendo dez (20 canais) em cada cão. Antes da obturação, os canais foram distribuídos, aleatoriamente, em sete grupos. Nos grupos I – GI (n=32) e controle negativo I – C-I (n=16), os canais foram obturados com cones de guta-percha e AH Plus; nos grupos II – GII (n=32) e controle negativo II – C-II (n=16), com cones de guta-percha e EndoRez; e nos grupos III – GIII (n=32) e controle negativo III – C-III (n=16), com cones de Resilon e Real Seal. Os canais do grupo controle positivo – C+ (n=16) não foram obturados. Imediatamente após a obturação, realizou-se a desobturação parcial dos canais, restando 4 mm de material na região apical. Os dentes foram selados, provisoriamente, com amálgama de prata, durante 72 horas. Após esse período, o selamento coronário de todos os canais, com exceção dos pertencentes aos grupos C-, foi removido, ficando expostos ao meio bucal por 90 dias. Os animais foram mortos, e as mandíbulas e maxilas removidas e seccionadas, separando-se o lado esquerdo do direito. Nos dentes das hemi-arcadas do lado esquerdo, o selamento dos canais dos grupos C- foi removido e o espaço protético irrigado, abundantemente, com água destilada. Após, foram secos e preenchidos com tinta nanquim. Os dentes foram, novamente, selados e, passadas 96 horas, extraídos. A seguir, as raízes foram separadas, armazenadas em tubos de ensaio e diafanizadas. Os espécimes do lado direito foram processados histologicamente, empregando-se as colorações de Hematoxilina e Eosina de Harris (HE) e Brown e Brenn (BB). A infiltração de corante foi medida com auxílio de lupa esteroscópica, com aumento de 10x. A análise dos cortes histológicos foi realizada em microscópio óptico, classificando-se o estado inflamatório dos tecidos periapicais e a infiltração microbiana em escores de 1 a 4. Os resultados da infiltração de corante evidenciaram que todos os grupos apresentaram menor infiltração que o grupo C+ (p<0,001) e que os grupos GI, GII e GIII não diferiram significativamente (P>0,05). O grupo GII apresentou diferenças significativas em relação ao seu grupo controle negativo, mostrando maior infiltração de corante (P<0,001). Na análise histológica, todos os materiais testados apresentaram menor grau de reação inflamatória e de infiltração microbiana, quando comparados com o grupo C+ (P≤0,001). Além disso, não foram observadas diferenças significativas entre os grupos GI, GII e GIII, bem como destes com seus respectivos controles (P>0,05). O teste de correlação de Spearman mostrou uma forte correlação entre resposta inflamatória e infiltração microbiana (rs= 0,57; P<0,001). A partir do exposto, concluiu-se que os materiais testados não apresentaram diferenças significativas entre si e que a resposta inflamatória periapical apresentou correlação direta com a infiltração coronária microbiana. / The aim of this study was to assess in vivo the sealing ability of three resin-containing endodontic sealers, two associated with gutta-percha points (AH Plus and EndoRez) and one associated with Resilon points (RealSeal). Mongrel dogs had their premolars prepared and filled, then post-prepared, which space became exposed to the oral environment. The correlation between inflammatory condition and level of microbial leakage was also tested. For that purpose, 80 teeth (160 root canals), being 10 (20 root canals), for each dog, were chemo-mechanically prepared and randomly divided into the following groups: GI (n=32) and C-I (negative control; n=16): root filling with gutta-percha and AH-Plus; GII (n=32) and C-II (n=16): root filling with gutta-percha and Endorez; GIII (n=32) and C-III (n=16): root filling with Resilon and RealSeal; C+ (positive control; n=16): no root filling. Immediately following filling procedures, post space preparation was done leaving 4mm of filling material apically. Teeth had their crowns provisionally sealed with amalgam for 72 hours. Then, coronal seal was removed (except for C-) and remained exposed to the oral environment for 90 days. The dogs were sacrificed and their mandible and maxilla were removed and sectioned, separating right and left sides. In the specimens from the left side, the C- teeth had their seal removed, and all teeth had their post space irrigated with distilled water, then filled with India ink. Following 96 hours, the teeth were extracted. Roots were labeled as to the groups and subjected to clearing process in test tubes. The specimens from the right side were histologically processed and stained with Hematoxicilin and Eosin (HE) and Brown and Brenn (BB). The ink leakage was measured three dimensionally under stereoscope microscopy (10x). Histological sections were assessed under light microscopy by a senior observer blinded as to the groups and the inflammatory state was classified using scores varying from 1 to 4 in an ascending severity. The same severity scoring applied to the microbial leakage, being the severity scored as to the depth of microbial penetration within the dentinal tubules. The results showed that all the test groups displayed less leakage than C+ group (P<0,001). GI, GII and GIII did not differ statistically amongst them. Sealing ability of GII differed significantly to its control group – C-II (P<0,001).Histological analysis showed that all test groups displayed lower inflammatory reaction and microbial leakage when compared to C+ group (P≤0,001). No significant differences were found amongst GI, GII and GIII and their respective controls (p>0,05). Spearman correlation test showed a strong correlation between inflammatory response and microbial leakage (rs= 0,57; P<0,001). It could be concluded that the tested materials did not differ amongst themselves and that the periapical tissue response correlated directly with the microbial coronal leakage.

O presente estudo teve como objetivo avaliar in vivo a capacidade de selamento de três materiais obturadores constituídos de cimentos endodônticos resinosos, sendo dois (AH Plus e EndoRez) associados a cones de guta-percha, e um (Real Seal) a cones de Resilon, em pré-molares de cães, expostos ao meio bucal, após o preparo para colocação de pino protético. Objetivou, também, avaliar a correlação entre a situação inflamatória dos tecidos periapicais e a infiltração microbiana. Para tal, foi realizado o preparo químico-mecânico de 80 dentes (160 canais), sendo dez (20 canais) em cada cão. Antes da obturação, os canais foram distribuídos, aleatoriamente, em sete grupos. Nos grupos I – GI (n=32) e controle negativo I – C-I (n=16), os canais foram obturados com cones de guta-percha e AH Plus; nos grupos II – GII (n=32) e controle negativo II – C-II (n=16), com cones de guta-percha e EndoRez; e nos grupos III – GIII (n=32) e controle negativo III – C-III (n=16), com cones de Resilon e Real Seal. Os canais do grupo controle positivo – C+ (n=16) não foram obturados. Imediatamente após a obturação, realizou-se a desobturação parcial dos canais, restando 4 mm de material na região apical. Os dentes foram selados, provisoriamente, com amálgama de prata, durante 72 horas. Após esse período, o selamento coronário de todos os canais, com exceção dos pertencentes aos grupos C-, foi removido, ficando expostos ao meio bucal por 90 dias. Os animais foram mortos, e as mandíbulas e maxilas removidas e seccionadas, separando-se o lado esquerdo do direito. Nos dentes das hemi-arcadas do lado esquerdo, o selamento dos canais dos grupos C- foi removido e o espaço protético irrigado, abundantemente, com água destilada. Após, foram secos e preenchidos com tinta nanquim. Os dentes foram, novamente, selados e, passadas 96 horas, extraídos. A seguir, as raízes foram separadas, armazenadas em tubos de ensaio e diafanizadas. Os espécimes do lado direito foram processados histologicamente, empregando-se as colorações de Hematoxilina e Eosina de Harris (HE) e Brown e Brenn (BB). A infiltração de corante foi medida com auxílio de lupa esteroscópica, com aumento de 10x. A análise dos cortes histológicos foi realizada em microscópio óptico, classificando-se o estado inflamatório dos tecidos periapicais e a infiltração microbiana em escores de 1 a 4. Os resultados da infiltração de corante evidenciaram que todos os grupos apresentaram menor infiltração que o grupo C+ (p<0,001) e que os grupos GI, GII e GIII não diferiram significativamente (P>0,05). O grupo GII apresentou diferenças significativas em relação ao seu grupo controle negativo, mostrando maior infiltração de corante (P<0,001). Na análise histológica, todos os materiais testados apresentaram menor grau de reação inflamatória e de infiltração microbiana, quando comparados com o grupo C+ (P≤0,001). Além disso, não foram observadas diferenças significativas entre os grupos GI, GII e GIII, bem como destes com seus respectivos controles (P>0,05). O teste de correlação de Spearman mostrou uma forte correlação entre resposta inflamatória e infiltração microbiana (rs= 0,57; P<0,001). A partir do exposto, concluiu-se que os materiais testados não apresentaram diferenças significativas entre si e que a resposta inflamatória periapical apresentou correlação direta com a infiltração coronária microbiana. / The aim of this study was to assess in vivo the sealing ability of three resin-containing endodontic sealers, two associated with gutta-percha points (AH Plus and EndoRez) and one associated with Resilon points (RealSeal). Mongrel dogs had their premolars prepared and filled, then post-prepared, which space became exposed to the oral environment. The correlation between inflammatory condition and level of microbial leakage was also tested. For that purpose, 80 teeth (160 root canals), being 10 (20 root canals), for each dog, were chemo-mechanically prepared and randomly divided into the following groups: GI (n=32) and C-I (negative control; n=16): root filling with gutta-percha and AH-Plus; GII (n=32) and C-II (n=16): root filling with gutta-percha and Endorez; GIII (n=32) and C-III (n=16): root filling with Resilon and RealSeal; C+ (positive control; n=16): no root filling. Immediately following filling procedures, post space preparation was done leaving 4mm of filling material apically. Teeth had their crowns provisionally sealed with amalgam for 72 hours. Then, coronal seal was removed (except for C-) and remained exposed to the oral environment for 90 days. The dogs were sacrificed and their mandible and maxilla were removed and sectioned, separating right and left sides. In the specimens from the left side, the C- teeth had their seal removed, and all teeth had their post space irrigated with distilled water, then filled with India ink. Following 96 hours, the teeth were extracted. Roots were labeled as to the groups and subjected to clearing process in test tubes. The specimens from the right side were histologically processed and stained with Hematoxicilin and Eosin (HE) and Brown and Brenn (BB). The ink leakage was measured three dimensionally under stereoscope microscopy (10x). Histological sections were assessed under light microscopy by a senior observer blinded as to the groups and the inflammatory state was classified using scores varying from 1 to 4 in an ascending severity. The same severity scoring applied to the microbial leakage, being the severity scored as to the depth of microbial penetration within the dentinal tubules. The results showed that all the test groups displayed less leakage than C+ group (P<0,001). GI, GII and GIII did not differ statistically amongst them. Sealing ability of GII differed significantly to its control group – C-II (P<0,001).Histological analysis showed that all test groups displayed lower inflammatory reaction and microbial leakage when compared to C+ group (P≤0,001). No significant differences were found amongst GI, GII and GIII and their respective controls (p>0,05). Spearman correlation test showed a strong correlation between inflammatory response and microbial leakage (rs= 0,57; P<0,001). It could be concluded that the tested materials did not differ amongst themselves and that the periapical tissue response correlated directly with the microbial coronal leakage.

No description available.

Amine groups physiologically play an important role in regulating the growth behavior of cells and they have technological advantages for the conjugation of biomolecules. In this work, we present a method to deposit a copolymerized coating of dopamine and hexamethylendiamine (HD) (PDAM/HD) rich in amine groups onto a target substrate. This method only consists of a simple dip-coating step of the substrate in an aqueous solution consisting of dopamine and HD. Using the technique of PDAM/HD coating, a high density of amine groups of about 30 nmol cm⁻² was obtained on the target substrate surface. The PDAM/HD coating showed a high cross-linking degree that is robust enough to resist hydrolysis and swelling. As a vascular stent coating, the PDAM/HD presented good adhesion strength to the substrate and resistance to the deformation behavior of compression and expansion of a stent. Meanwhile, the PDAM/HD coating exhibited good biocompatibility and attenuated the tissue response compared with 316L stainless steel (SS). The primary amine groups of the PDAM/HD coating could be used to effectively immobilize biomolecules containing carboxylic groups such as heparin. These data suggested the promising potential of this PDAM/HD coating for application in the surface modification of biomedical devices.