Magister Scientiae Dentium - MSc(Dent) / Statement of problem: Although bioceramic endodontic sealer cements offer various advantages over conventional zinc oxide-based and resin-based cements, questions have been raised about the ability to retreat root canals that have been sealed using these cements. Aims and Objectives: The aim of the study was to determine the retreatability of root canals sealed using a bioceramic calcium silicate-based sealer cement. The objectives were to determine the possibility of achieving working length and apical patency when obturation is done with the master GP placed at working length and when it is short by 3mm. The time it took to achieve these parameters when it was possible to achieve them was also determined. The role of XP Endo Finisher R, a supplementary retreatment file, in achieving working length and apical patency was also to be evaluated. However, this latter aspect was eliminated after the pilot study, when it was found not to have an effect in regaining working length and apical patency.

Introduction: The primary reason for endodontic treatment failure is microbial infection inside the root canal system by different microbes including Enterococcus faecalis. Endodontic sealers with Chitosan (CS), a compound with antimicrobial effects, can decrease the growth of microorganisms and potentially prevent failure. Purpose: The aim of this study was to assess the antimicrobial activity ex-vivo and flowability of calcium silicate root canal sealers with added CS fillers. Materials and methods: EndoSequence (BC) sealer was mixed with CS fillers in two different concentrations (5% and 10%wt). Flowability was analyzed according to ISO-6876. The antibacterial assessment was conducted using an ex-vivo model. Extracted single-rooted teeth were infected with E. faecalis for 7 days. Follow the root canal treatment, the sealers (BC, BC+CS-5%, BC+CS-10%, N=6) were used for obturation and re-incubated in the bioreactor for 24 hours. Untreated teeth were used as positive control. Cell viability (CFU/mL) and fluorescence microscopy were used to determine the number of bacteria at the bonded interface. ANOVA was used for statistical analysis. Results: Addition of CS fillers into BC resulted in a significant decrease in flowability (BC:22mm, BC+CS-5%:19mm, BC+CS-10%:16mm). All evaluated sealers showed antibacterial activity. The addition of CS significantly reduced the viable cells (log(CFU/mL)) (CS-5%:5.3, CS-10%:4.6) compared with the BC (5.9) and positive control (7.2). Fluorescence analysis showed that CS-Sealers group had an increased number of dead cells (CS-10%:77.3%, CS-5%:64.4%) compared with the BC-Sealer (37.9%) and positive control (23.3%). Conclusion: Endodontic sealers with added CS enhanced antimicrobial effects of the sealer. However, adding more than 5% of CS affects the flow properties of the sealer. / Oral Biology

Purpose: The aim of this study was to assess the outcome of treatment of teeth with open apices managed by the orthograde placement of a bioceramic apical barrier as well as to identify potential outcome factors for this type of treatment. Methods: Patient records were pooled from graduate resident cases completed at Virginia Commonwealth University between January 1, 2010 and May 31, 2018. A total of 515 patients were identified using relevant ADA codes and a key word search within the patient record database. A total of 104 patients (119 teeth) had an open apex that had NSRCT utilizing a bioceramic apical barrier, with 32 of the patients (36 teeth) returning for follow-up. Results: Of the 36 examined teeth (30.8% recall rate),72% were considered healed. 92% were considered healed or healing. No predictive variable analyzed had a significant effect on the outcome. Conclusion: Overall, these results indicate that a bioceramic apical barrier technique is a promising treatment option for obturating teeth with open apices during NSRCT.

Orientador: João Guilherme Padilha Filho / Banca: Paola Castro Morais / Banca: Patricia Popak Giordano / Banca: Delphim da Graça Macoris / Banca: Márcia Rita Fernandes Machado / Resumo: Objetivou-se nesta pesquisa estudar o comportamento e a bioatividade do cimento de alfa-fosfato tricalcico de dupla pega em artrodeses tarsocrurais. Utilizaram-se seis caes, adultos, macho ou femeas, sem raca definida, com idades entre dois e cinco anos e pesando entre 18 e 30 kg. Foram constituidos dois grupos com 3 animais cada: um grupo onde empregou-se o cimento de ¿-fosfato tricalcico de dupla pega (Grupo I) e outro utilizando osso esponjoso autogeno (Grupo II). A avaliacao radiografica ocorreu aos 30, 45, 60, 90 e 120 dias apos o procedimento cirurgico. Radiograficamente, a fusao dos ossos das articulacoes ocorreu em ambos os grupos apos o 30o dia, sem qualquer reacao adversa ou do tipo corpo estranho. A estabilidade das articulacoes foi satisfatoria com a utilizacao de fixadores esqueleticos externos. Histologicamente, aos 120 dias, observaram-se diferencas na maturidade das celulas osseas entre os dois grupos ocorrendo absorcao lenta e remodelacao da bioceramica (Grupo I). Relativamente a microscopia eletronica de varredura, foi observada formacao de osso novo diretamente na superficie da bioceramica, sem causar formacao de lacuna entre a interface osso-ceramica. O cimento de alfa-fosfato tricalcico de dupla pega demonstrou ter uma boa resistencia mecanica, propriedades de biocompatibilidade, crescimento osseo direto sobre a ceramica, osteoconducao e, ainda, ocorrencia de lenta absorcao quando comparado ao enxerto ósseo. / Abstract: The purpose of this research was to estuding the behaviour and bioactivity of the á-tricalcium phosphate cement double setting in tarsocrural arthrodesis. Therefore, six canines, both male and female adults mongrel dogs, aged between two and five years old and weighing between 12 and 18kg, were the objects of this study. They were vi divided into two groups with three animals each. On Group I á-tricalcium phosphate cement double setting was used. The Group II, also considered the control group, autogenous cancellous bone graft was used. The periods chosen for the radiographic analysis were 30, 45, 60, 90 and 120 days after surgery. Radiographyc bone fusions on the joints were observed on both groups after 30 days. The stabilization of the joints with external fixators proved to be very satisfactory. No reaction of foreigh body or infection process due to the material used was observed. The histological analysis performed after 120 days after surgery revealed differences in terms of the maturity of the bone cells between the two groups, showing slow absorption and remodelling of the bioceramic (Group I). In terms of the scanning electronic microscopy, bone growth was detected, right on the surface of the bioceramic, without causing gap formation on the bone-ceramic joint. The á-tricalcium phosphate cement double setting demonstrated to have a good mechanical resistance, bioacompatibility properties, direct bone growth on the ceramic and osteocondution and, still, the occurrence of slow absorption when compared to the bone graft. / Doutor

A necessidade de obtenÃÃo de novos materiais para substituiÃÃo de partes do corpo humano que foram destruÃdas ou danificadas conduziu cientistas das mais diferentes Ãreas à investigaÃÃo de novos materiais utilizados para implantes O fosfato de cÃlcio quando cristalizado na forma de hidroxiapatita [Ca10(PO4)6(OH)2] à uma cerÃmica bioativa e biocompatÃvel, similar quimicamente ao tecido natural de ossos e dentes O presente trabalho tem como objetivos a produÃÃo de biocerÃmicas de apatitas nanomÃtricas via sol-gel a obtenÃÃo materiais compÃsitos a base de hidroxiapatita e alumina variando a concentraÃÃo de alumina e a avaliaÃÃo das propriedades fÃsicas mecÃnicas quÃmicas e da microestrutura das amostras sinterizadas As propriedades e caracterÃsticas das biocÃramicas foram analisadas utilizando-se as tÃcnicas de difraÃÃo de raios X e espectroscopia de infravermelho microscopia eletrÃnica de varredura (MEV) analise granulomÃtrica ensaio de resistÃncia mecÃnica por compressÃo diametral em amostras prensadas e teste de bioatividade Com os resultados de raios X foi possÃvel identificar os picos representativos em todas as amostras de fases correspondentes à hidroxiapatita como tambÃm fosfato de alumÃnio Ãxido de cÃlcio alumÃnio e Ãxido de cÃlcio Na anÃlise de infravermelho foi possÃvel identificar os grupos presentes nos nanocompÃsitos Os ensaios de resistÃncia à traÃÃo por compressÃo diametral nas diferentes composiÃÃes de nanocompÃsitos mostraram que a porcentagem de alumina presente influencia na resistÃncia mecÃnica do material / The need for obtaining new materials to replace human body parts that were destroyed or damaged led scientists from different research areas of new materials used for implants Calcium phosphate when crystallized in the form of hydroxyapatite [Ca10 (PO4)6 (OH)2 ] is a bioactive and biocompatible ceramics primarily similar to natural bone and teeth ratio This workaims to produce nanometrics apatite bioceramics via sol - gel, get composites based on hydroxyapatite and alumina materials by varying the concentration of alumina and evaluate mechanical chemical physical properties and microstructure of the sintered samples The properties and characteristics of bioceramics were analyzed using the techniques of X-ray diffraction and infrared spectroscopy scanning electron microscopy (SEM particle size analysis test strength by diametrical compression pressed samples and bioactivity test From the results of X ray was it possible to identify the representative peaks in all samples corresponding to hydroxyapatite phase but also to aluminum phosphate aluminum calcium oxide and calcium oxide From in infrared analysis it was possible to identify the groups present in nanocompÃsitos Tensile strength obtained by diametrical compression on different compositions of nanocomposites showed that the percentage of alumina present influences the mechanical strength of the material

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A biocerÃmica de hidroxiapatita (HA) Ã um material biocompatÃvel no corpo humano e pode ser uma importante ferramenta em aplicaÃÃes de hipertermia para o tratamento no cÃncer Ãsseo. Neste trabalho investigou-se o efeito da adiÃÃo de Ãons de ferro na estrutura da HA com o objetivo de obter uma biocerÃmica que venha ser utilizado no tratamento hipertÃrmico contra o cÃncer. As amostras foram preparadas pelo mÃtodo cerÃmico e caracterizadas pela difraÃÃo de raios-X, espectroscopia do infravermelho (FTIR), microdureza Vickers, medidas elÃtricas (constante e perda dielÃtrica) e microscopia eletrÃnica de varredura (MEV). AtravÃs da difraÃÃo de raios-X verificou-se a presenÃa da fase Ca2Fe2O5 que apresenta uma estrutura denominada Brownmillerite. Verificou-se melhoria das propriedades mecÃnicas e elÃtricas com o aumento da temperatura de sinterizaÃÃo. Observou-se que o aumento da concentraÃÃo de ferro e da temperatura de sinterizaÃÃo ocasionaram mudanÃas morfolÃgicas nos grÃos. / The bioceramic called hydroxyapatite (HA) is a biocompatible material which can be an important tool in hyperthermia applications for the treatment of bony cancer. In this work the effect of the addition of Fe ions in the structure of the HA was investigated with the objective of obtaining a magnetic bioceramic to be used in the hyperthermic treatment against the cancer. The samples were prepared by the ceramic method and characterized by the X-ray diffraction (XRD), infrared spectroscopy (FTIR), Vickers hardness, electric properties (constant and loss dielectric) and scanning electronic microscopy (SEM). The presence of the phase Ca2Fe2O5 was verified by X-ray diffraction analysis, showing a structure Brownmillerite. The improvement of the mechanical and electric properties was verified with the increase of the sintering temperature. It was observed that the increase of the Fe addition and the sintering temperature caused morphologic changes in the grains.

Made available in DSpace on 2014-06-11T19:31:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-03-28Bitstream added on 2014-06-13T20:21:57Z : No. of bitstreams: 1 doreaneto_fa_dr_jabo.pdf: 1608125 bytes, checksum: 3f4786116d52404397afbb4ba51cd232 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Objetivou-se nesta pesquisa estudar o comportamento e a bioatividade do cimento de alfa-fosfato tricalcico de dupla pega em artrodeses tarsocrurais. Utilizaram-se seis caes, adultos, macho ou femeas, sem raca definida, com idades entre dois e cinco anos e pesando entre 18 e 30 kg. Foram constituidos dois grupos com 3 animais cada: um grupo onde empregou-se o cimento de ¿-fosfato tricalcico de dupla pega (Grupo I) e outro utilizando osso esponjoso autogeno (Grupo II). A avaliacao radiografica ocorreu aos 30, 45, 60, 90 e 120 dias apos o procedimento cirurgico. Radiograficamente, a fusao dos ossos das articulacoes ocorreu em ambos os grupos apos o 30o dia, sem qualquer reacao adversa ou do tipo corpo estranho. A estabilidade das articulacoes foi satisfatoria com a utilizacao de fixadores esqueleticos externos. Histologicamente, aos 120 dias, observaram-se diferencas na maturidade das celulas osseas entre os dois grupos ocorrendo absorcao lenta e remodelacao da bioceramica (Grupo I). Relativamente a microscopia eletronica de varredura, foi observada formacao de osso novo diretamente na superficie da bioceramica, sem causar formacao de lacuna entre a interface osso-ceramica. O cimento de alfa-fosfato tricalcico de dupla pega demonstrou ter uma boa resistencia mecanica, propriedades de biocompatibilidade, crescimento osseo direto sobre a ceramica, osteoconducao e, ainda, ocorrencia de lenta absorcao quando comparado ao enxerto ósseo. / The purpose of this research was to estuding the behaviour and bioactivity of the á-tricalcium phosphate cement double setting in tarsocrural arthrodesis. Therefore, six canines, both male and female adults mongrel dogs, aged between two and five years old and weighing between 12 and 18kg, were the objects of this study. They were vi divided into two groups with three animals each. On Group I á-tricalcium phosphate cement double setting was used. The Group II, also considered the control group, autogenous cancellous bone graft was used. The periods chosen for the radiographic analysis were 30, 45, 60, 90 and 120 days after surgery. Radiographyc bone fusions on the joints were observed on both groups after 30 days. The stabilization of the joints with external fixators proved to be very satisfactory. No reaction of foreigh body or infection process due to the material used was observed. The histological analysis performed after 120 days after surgery revealed differences in terms of the maturity of the bone cells between the two groups, showing slow absorption and remodelling of the bioceramic (Group I). In terms of the scanning electronic microscopy, bone growth was detected, right on the surface of the bioceramic, without causing gap formation on the bone-ceramic joint. The á-tricalcium phosphate cement double setting demonstrated to have a good mechanical resistance, bioacompatibility properties, direct bone growth on the ceramic and osteocondution and, still, the occurrence of slow absorption when compared to the bone graft.

Made available in DSpace on 2015-04-22T19:34:47Z (GMT). No. of bitstreams: 1 Iuri Bezerra de Barros.pdf: 5108472 bytes, checksum: b350a4dc9e9fc12bf6dad371b4ed93fb (MD5) Previous issue date: 2013-08-30 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Sponges have enormous biotechnological potential in natural products research due to several biological activities exhibited by their extracts and isolated compounds. Although the majority of studies reported are with marine sponges, there are indications of great variability of secondary metabolites are also present in freshwater sponges. The absence of chemical studies of these organisms in Amazonia motivated the present work, with a broad survey of the species and organic and inorganic chemiscal studies. Several expeditions in Amazon region allowed the collection of sponges in different rivers. Taxonomic identification was performed by means of optical microscopy techniques, which allowed the observation of the remarkable abundance of family Metaniidae specimens of the genus Metania and Drulia, with the genus Acalle also found. The other two families reported in the Neotropics were also found: Spongillidae with genus Trochospongilla and Corvospongilla, and Potamolepidae, with the genus Oncosclera. The elemental composition of the sponges was determined by Xray fluorescence, allowing the identification of some characteristics for groups of sponges. We can stand out the absent from aluminum in Metania genus and presence in all other species studied. Ca, K and Ti were not detected only in the M. fittkaui species. The species Trochospongilla paulula showed ability to accumulate vanadium. Two methodologies were evaluated for the purification of silica present in these organisms, the first involving the solubilization and selective precipitation, and the second employing highly oxidizing solutions, followed by calcination. The purification of silica afforded the product with purity near of silica commercially available for support to liquid chromatography. Steroidal fractions obtained from apolar sponges extracts were derivatized and analyzed by gas chromatography and the majority sterols were identified. The sterol 24-ethyl-cholest-5,22-dien-3β-ol proved to be majoritary in the samples of the families Metaniidae and Potamolepidae, different from Spongillidae in which cholesterol is found in highest concentration. There were identified three other sterol 24-methyl-cholesta-5,22-dien-3β-ol, 24-methyl-cholest-5-en-3β-ol and 24- ethyl-cholest-5-en-3β-ol and three ketosteroids cholest-4-ene-3-one, 24-methyl-cholest-4,22- dien-3-one and 24-ethyl-cholest-4,22-dien-3-one so far unpublished in freshwater sponge.. / As esponjas possuem um enorme potencial biotecnológico na pesquisa de produtos naturais devido às diversas atividades biológicas atribuídas a seus extratos e substâncias isoladas. Apesar da maioria dos estudos relatados com esponjas serem de organismos marinhos, existem indícios de grande variabilidade de metabólitos secundários também em esponjas de água-doce. A ausência de estudos químicos desses organismos na Amazônia motivou a realização do presente trabalho, com um amplo levantamento de espécies e estudos de química orgânica e inorgânica. Diversas excursões na região Amazônica permitiram a coleta de esponjas em diferentes rios. A identificação taxonômica foi realizada por meio de técnicas de microscopia óptica, que permitiram observar a notável abundância de espécimes da família Metaniidae destacando os gêneros Metania e Drulia, e o gênero Acalle encontrado com menor frequência. As outras duas famílias relatadas na região neotropical também foram encontradas: Spongillidae, com os gêneros Trochospongilla e Corvospongilla; e Potamolepidae, com o gênero Oncosclera. A composição elementar das esponjas foi determinada por fluorescência de raios-X, permitindo a identificação de algumas características para grupos de esponjas. Pode-se destacar o alumínio ausente no gênero Metania e presente em todas as demais espécies estudadas; Ca. K e Ti que não foram detectados somente na espécie M. fittkaui; e a espécie Trochospongilla paulula apresentou capacidade de acumular vanádio. Foram avaliadas duas metodologias para a purificação da sílica presente nestes organismos, a primeira envolvendo a solubilização e precipitação seletiva, e a segunda envolvendo soluções altamente oxidantes seguida por calcinação. A purificação da sílica permitiu a obtenção de produtos com grau de pureza próximo a sílica disponível comercialmente como suporte para cromatografia liquída. Frações esteroídicas obtidas apartir dos extratos apolares destas esponjas foram derivatizadas e analisadas por cromatografia em fase gasosa, sendo identificados os esteróis majoritários presentes. O esterol 24-etil-colesta-5,22-dieno-3β-ol se mostrou majoritário nas amostras das famílias Metaniidae e Potamolepidae, diferenciando-as da Spongillidae na qual o colesterol é encontrado em maior concentração. Foram identificados outros três esteróis 24-metil-colesta-5,22-dieno-3β-ol, 24- metil-colesta-5-eno-3β-ol e 24-etil- colesta-5-eno-3β-ol e três cetoesteroides colesta-4-eno-3- ona, 24-metil-colesta-4,22-dieno-3-ona e 24-etil-colesta-4,22-dieno-3- até então inéditas em esponjas dulcicolas.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Os nanocompÃsitos a base de fosfatos de cÃlcio contribuem significativamente em tratamentos traumatolÃgicos, na cicatrizaÃÃo da estrutura Ãssea traumatizada, na regeneraÃÃo Ãssea e na reconstituiÃÃo Ãssea. Este trabalho teve como objetivo a produÃÃo de nanocompÃsitos a partir de pÃs de biocerÃmicas obtidas por precipitaÃÃo em soluÃÃo aquosa, reforÃados com diÃxido de silÃcio (SiO2). Os nanocompÃsitos foram produzidos em laboratÃrio com a adiÃÃo de sÃlica nanomÃtrica nas proporÃÃes de 15%, 35% e 50% em peso ao beta fosfato tricÃlcio nanomÃtrico. As amostras foram caracterizadas por difraÃÃo de raios-X, espectroscopia no infravermelho com transformada de Fourier (FTIR), microscopia eletrÃnica de varredura (MEV), espectroscopia de energia dispersiva de raios-x (EDX) e ensaio de resistÃncia mecÃnica por compressÃo diametral em amostras prensadas. Com os resultados de raios-X foi possÃvel identificar os picos representativos do beta fosfato tricÃlcio e observar que a intensidade dos picos diminui com o aumento da porcentagem de sÃlica nos nanocompÃsitos. Na anÃlise de FTIR foi possÃvel identificar os grupos presentes nos nanocompÃsitos. Os resultados obtidos na anÃlise de caracterizaÃÃo morfolÃgica apresentaram uma superfÃcie formada por partÃculas equiaxiais interligadas, e nÃo foi possÃvel verificar a dispersÃo das nanopartÃculas de sÃlica. Os ensaios de resistÃncia à traÃÃo por compressÃo diametral nas diferentes composiÃÃes de nanocompÃsitos mostraram que a porcentagem de sÃlica presente influencia na resistÃncia mecÃnica do material. / Calcium phosphate nanocomposites can be very useful in traumatologic treatments, for the healing of traumatized bone structure, for bone regeneration and bone reconstruction. This work aimed at the production of nanocomposites where a bioceramic matrix is reinforced with nanocrystalline silica (SiO2) particles. The matrix was produced from bioceramic nanopowders (beta tricalcium phosphate, β-TCP) obtained by precipitation in aqueous solution. The nanocomposites were produced in the laboratory by adding nanometric silica particles to the nanometric β-TCP in proportions 15%, 35% e 50% by weight. The material was characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and diametral compression testing of pressed disk samples. XRD results presented the characteristic peaks of β-TCP, which became less intense as the amount of silica particles increased. FTIR spectra allowed for the identification of groups present in the nanocomposites. SEM micrographs gave an idea of the microstructural of morphological aspects of the material, and showed that the surfaces consisted of a network of interconnected equiaxed particles. It was not possible to observe the dispersion of the silica particles. Diametral compression test results showed that the amount of silica influences the mechanical strength of the nanocomposite.

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