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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Characterization of bulk-fill and conventional light-cured resin-composites in terms of composition and polymer matrix properties

Alshali, Ruwaida January 2016 (has links)
Resin-composites have been used in dentistry as direct restorative materials for over fifty years ago, and meanwhile their properties have been substantially improved. Recently a new class of light-cured resin-composites known as 'bulk-fill' materials has been introduced, and has increased the practical application of resin-composites in comparison to conventional incrementally applied materials. The aim of the present research was to assess bulk-fill resin-composites in comparison to conventional materials with respect to their composition, polymeric structure properties and hygroscopic behaviour in oral and food simulating substances. A variety of bulk-fill and conventional resin-composites were tested in this study. Monomer composition of materials has been qualitatively and quantitatively determined using high performance liquid chromatography and mass spectroscopy, and their degree of conversion assessed using Fourier transform infrared spectroscopy. It was found that the degree of conversion of the bulk-fill resin-composites was generally comparable to that of conventional materials and appeared to be governed by the type and quantity of monomers comprising the resin matrix. To evaluate the cross-link density of the polymer matrix, the extent of post-irradiation hardness development, chemical softening, and thermal stability were assessed using microhardness and thermogravimetric analysis. Materials showed variable results and it was suggested that two networks were present in the polymerized resin matrix, a primary network forming immediately after curing followed by a secondary network. The secondary network seemed to have poor cross-link density with low resistance to the degradative effects of solvents. Monomer elution from cured materials was assessed using High performance liquid chromatography over three months' storage in three different media. Elution from bulk-fill resin-composites was found to be comparable to that of conventional materials, despite their increased incremental thickness, with remarkably minimal elution taking place from two bulk-fill materials examined. Monomer elution was shown to be highly dependent on the hydrophobicity of the base monomers and the network characteristics of the resin-matrix. UDMA-BisEMA based systems appeared to be more vulnerable in organic solutions than BisGMA and BisGMA-BisEMA based systems in terms of monomer elution. Sorption and solubility were assessed after one years' storage in water and artificial saliva. Water sorption and solubility of resin-composites were material-dependent and highly affected by the filler loading and initial degree of conversion of the polymeric matrix. BisEMA and UDMA-BisEMA based polymer networks appeared to be more hydrophobic and resistant to sorption and solubility than BisGMA based systems in water based media. The bulk-fill and conventional resin-composites tested were considered stable in the long-term water storage, with the exception of one conventional flowable material.
2

Estudio de la profundidad de polimerización de resinas bulk fill a diferentes distancias de fotoactivación

Boza Quiñones, Yerlin Rubí January 2015 (has links)
Las propiedades físicas de las resinas compuestas son muy importantes, por ello el objetivo del presente estudio fue determinar la profundidad de polimerización de las resinas “bulk fill” al ser fotoactivadas a diferentes distancias. La parte experimental se realizó utilizando el método ISO 4049, se elaboraron 36 moldes cilíndricos de 4mm de diámetro y 12 mm de altura, en las cuales se colocó la resina; se elaboraron 12 muestras de cada resina (resina A y resina B) y se dividieron de acuerdo a la distancia de fotoactivación (0mm y 4mm) por lo que se obtuvieron 6 grupos con 6 muestras de resina en cada grupo, todas se polimerizaron por LED a 10 segundos. La medición de la altura absoluta polimerizada de las muestras se realizó con un micrómetro de 0,01mm de precisión, finalmente cada altura absoluta fue dividida entre 2 lo cual se registró como la profundidad de polimerización de cada muestra. Los datos fueron sometidos a la prueba T-Student para muestras independientes y a la prueba ANOVA con un nivel de confianza de 95%. Los resultados mostraron que la resina A presentó mayor profundidad de polimerización que la resina B para las dos distancias de fotoactivación (0mm y 4mm). Los datos mostraron valores de p<0.05 siendo estadísticamente significativa entre las resinas evaluadas. Se concluyó que las profundidades de polimerización de las resinas “bulk fill” están determinadas por la distancia de fotoactivación, la resina A presenta mayor profundidad de polimerización que la resina B. Palabras claves: profundidad de polimerización, resinas compuestas bulk fill. / --- The physical properties of the composites are very important so the aim of this study was to determine the depth of cure of resins "bulk fill" photoactivated at different distances. The experimental part was carried out using the ISO 4049 method, cylindrical molds 36 of 4mm diameter and 12 mm in height, in which the resin is placed is produced; 12 samples of each resin (resin A and resin B) were prepared and divided according to the distance of photoactivation (0mm and 4mm) so 6 groups were obtained with 6 resin samples in each group, all were polymerized by LED 10 seconds. Measuring the absolute height of all samples it was performed using a micrometer of 0.01mm accuracy absolute height finally each was divided between 2, which was recorded as the depth of cure of each sample. The data were submitted to the Student t-test for independent samples and ANOVA test with a confidence level of 95%. The results showed that the resin A showed further polymerisation resin B for the two distances photoactivation (0mm and 4mm). The data showed P values <0.05 were statistically significant between the resins evaluated. It was concluded that the depths of polymerization of the resins "bulk fill" are determined by the distance photoactivation, the resin A has greater depth of cure the resin B. Keywords: depth of cure, composites bulk fill.
3

Influência da técnica restauradora/ciclagem mecânica na adesão à dentina de pré-molares superiores / Influence of restorative technique/mechanical cycling on dentin adhesion of upper premolars

Matos, Laís Lopes Machado de 27 January 2017 (has links)
A resina bulk fill vem ampliando as indicações dos compósitos na qual permite a inserção em incrementos com espessura de até 5mm. A interface adesiva é a principal responsável pela durabilidade de restaurações estéticas. Objetivo: Avaliar a integridade da interface dente/restauração, e a resistência adesiva da dentina após a ciclagem mecânica de dentes restaurados com a resina bulk fill. Materiais e Métodos: Foram selecionados 40 prémolares superiores birradiculares que receberam um preparo MOD com término cervical mesial em esmalte e o término distal em dentina e foram divididos em 2 grupos: 1 incremento de resina e 2 incrementos de resina, e, dois subgrupos: com e sem ciclagem mecânica (n=10). Em seguida, os espécimes foram restaurados, analisados inicialmente em microscopia confocal a laser e posteriormente levados para ciclagem mecânica onde foram realizados 300.000 ciclos na frequência de 1Hz e carga de 80N. Após a ciclagem mecânica, os espécimes foram novamente avaliados em microscopia confocal a laser para avaliação da qualidade da interface, e foi realizado o teste de microtração na dentina das paredes proximais e pulpar dos dentes com ciclagem e sem ciclagem. Posteriormente, foi realizada a análise do padrão de fratura em microscopia confocal a laser. Os valores obtidos na mensuração de gaps foram analisados estatisticamente através da ANOVA seguido de Holm-Sidak; e os valores obtidos na microtração foram analisados estatisticamente através da ANOVA seguido de Tukey. Resultados: Observou-se que o fator incremento promoveu diferença estatística significante tanto em esmalte como em dentina antes e após a ciclagem (p<0,05). A ciclagem promoveu fendas tanto para esmalte como para dentina (p<0,05). Para resistência adesiva não foi observada diferença entre os grupos de 1 e 2 incrementos antes e após a ciclagem (p>0,05), nem na dentina em suas diferentes porções ao comparar os incrementos (p>0,05), mas foi possível observar diferença significante antes e após a ciclagem nas diferentes regiões de dentina (p<0,05). Conclusão: Previamente à ciclagem mecânica, o fator incremento não afetou a interface, a resistência adesiva e os términos cervicais proximais. Posteriormente à ciclagem, a qualidade da interface foi afetada negativamente, o término cervical em dentina apresentou fendas maiores, mas a resistência adesiva se manteve. A ciclagem mecânica influenciou o aumento da quantidade de gaps e trincas e prejudicou a adesão, principalmente na dentina da região distal. / The bulk fill resin extended the composites indications in which it allows the insertion in increments with thickness of up to 5mm. The adhesive interface is the main responsible for the durability of aesthetic restorations. Objective: To evaluate the integrity of the tooth/ restoration interface and dentin adhesive resistance after mechanical cycling of restored teeth with bulk fill resin. Materials and Methods: 40 upper biradicular premolars were selected for the study and received a MOD preparation with mesial cervical terminus in enamel and the distal cervical terminus in dentin and were divided into 2 groups: resin in 1 increment and resin in 2 increments, and 2 subgroups: with and without mechanical cycling (n = 10). Afterwards, the specimens were restored, initially analyzed by confocal laser scanning microscopy and submitted to mechanical cycling with 300,000 cycles, 1Hz frequency and 80N load. After the mechanical cycling, the specimens were evaluated again in confocal laser scanning microscopy to evaluate the interface quality, and microtensile test was performed on the dentin of the proximal walls and pulp of the teeth cycled or not. Later, the analysis of the fracture pattern was performed in confocal laser scanning microscopy. The values obtained in the measurement of gaps were analyzed by ANOVA following test Holm-Sidak and microtensile were analyzed by ANOVA following test Tukey. Results: The increment factor promoted a significant statistically difference for enamel (p <0.05) and dentin (p <0.05) after cycling. The cycling promoted significant cracks for enamel (p <0.05) and dentin (p <0.05). No difference in adhesive resistance was observed between the groups of resin in 1 and 2 increments, before and after cycling. There was no difference in dentin adhesive resistance in the different portions when the increments were compared, but it was possible to observe a significant difference (p <0.05) in the different regions of dentin (p <0.05). Conclusion: Previously to mechanical cycling, the increment factor did not affect the interface, the adhesive resistance and proximal cervical terminus. After the cycling, the interface quality was adversely affected, the cervical terminus in dentin presented higher cracks, but the adhesive resistance remained. Mechanical cycling influenced in the increase of gaps and cracks number and impaired the adhesion, mainly in the dentin of the distal region.
4

Influência da técnica restauradora/ciclagem mecânica na adesão à dentina de pré-molares superiores / Influence of restorative technique/mechanical cycling on dentin adhesion of upper premolars

Laís Lopes Machado de Matos 27 January 2017 (has links)
A resina bulk fill vem ampliando as indicações dos compósitos na qual permite a inserção em incrementos com espessura de até 5mm. A interface adesiva é a principal responsável pela durabilidade de restaurações estéticas. Objetivo: Avaliar a integridade da interface dente/restauração, e a resistência adesiva da dentina após a ciclagem mecânica de dentes restaurados com a resina bulk fill. Materiais e Métodos: Foram selecionados 40 prémolares superiores birradiculares que receberam um preparo MOD com término cervical mesial em esmalte e o término distal em dentina e foram divididos em 2 grupos: 1 incremento de resina e 2 incrementos de resina, e, dois subgrupos: com e sem ciclagem mecânica (n=10). Em seguida, os espécimes foram restaurados, analisados inicialmente em microscopia confocal a laser e posteriormente levados para ciclagem mecânica onde foram realizados 300.000 ciclos na frequência de 1Hz e carga de 80N. Após a ciclagem mecânica, os espécimes foram novamente avaliados em microscopia confocal a laser para avaliação da qualidade da interface, e foi realizado o teste de microtração na dentina das paredes proximais e pulpar dos dentes com ciclagem e sem ciclagem. Posteriormente, foi realizada a análise do padrão de fratura em microscopia confocal a laser. Os valores obtidos na mensuração de gaps foram analisados estatisticamente através da ANOVA seguido de Holm-Sidak; e os valores obtidos na microtração foram analisados estatisticamente através da ANOVA seguido de Tukey. Resultados: Observou-se que o fator incremento promoveu diferença estatística significante tanto em esmalte como em dentina antes e após a ciclagem (p<0,05). A ciclagem promoveu fendas tanto para esmalte como para dentina (p<0,05). Para resistência adesiva não foi observada diferença entre os grupos de 1 e 2 incrementos antes e após a ciclagem (p>0,05), nem na dentina em suas diferentes porções ao comparar os incrementos (p>0,05), mas foi possível observar diferença significante antes e após a ciclagem nas diferentes regiões de dentina (p<0,05). Conclusão: Previamente à ciclagem mecânica, o fator incremento não afetou a interface, a resistência adesiva e os términos cervicais proximais. Posteriormente à ciclagem, a qualidade da interface foi afetada negativamente, o término cervical em dentina apresentou fendas maiores, mas a resistência adesiva se manteve. A ciclagem mecânica influenciou o aumento da quantidade de gaps e trincas e prejudicou a adesão, principalmente na dentina da região distal. / The bulk fill resin extended the composites indications in which it allows the insertion in increments with thickness of up to 5mm. The adhesive interface is the main responsible for the durability of aesthetic restorations. Objective: To evaluate the integrity of the tooth/ restoration interface and dentin adhesive resistance after mechanical cycling of restored teeth with bulk fill resin. Materials and Methods: 40 upper biradicular premolars were selected for the study and received a MOD preparation with mesial cervical terminus in enamel and the distal cervical terminus in dentin and were divided into 2 groups: resin in 1 increment and resin in 2 increments, and 2 subgroups: with and without mechanical cycling (n = 10). Afterwards, the specimens were restored, initially analyzed by confocal laser scanning microscopy and submitted to mechanical cycling with 300,000 cycles, 1Hz frequency and 80N load. After the mechanical cycling, the specimens were evaluated again in confocal laser scanning microscopy to evaluate the interface quality, and microtensile test was performed on the dentin of the proximal walls and pulp of the teeth cycled or not. Later, the analysis of the fracture pattern was performed in confocal laser scanning microscopy. The values obtained in the measurement of gaps were analyzed by ANOVA following test Holm-Sidak and microtensile were analyzed by ANOVA following test Tukey. Results: The increment factor promoted a significant statistically difference for enamel (p <0.05) and dentin (p <0.05) after cycling. The cycling promoted significant cracks for enamel (p <0.05) and dentin (p <0.05). No difference in adhesive resistance was observed between the groups of resin in 1 and 2 increments, before and after cycling. There was no difference in dentin adhesive resistance in the different portions when the increments were compared, but it was possible to observe a significant difference (p <0.05) in the different regions of dentin (p <0.05). Conclusion: Previously to mechanical cycling, the increment factor did not affect the interface, the adhesive resistance and proximal cervical terminus. After the cycling, the interface quality was adversely affected, the cervical terminus in dentin presented higher cracks, but the adhesive resistance remained. Mechanical cycling influenced in the increase of gaps and cracks number and impaired the adhesion, mainly in the dentin of the distal region.
5

Efeito da espessura e do envelhecimento por solução ácida de diferentes resinas compostas bulk fill nas propriedades de microdureza superficial e fluorescência / Effect of resin thickness, solvent storage on the micro-hardness and fluorescence of bulk-fill resin composites

Ferreira, Lyvia Karla Cerci 10 February 2017 (has links)
Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2018-06-25T18:13:37Z No. of bitstreams: 2 Lyvia Karla Cerci Ferreira Bertacchini.pdf: 1676300 bytes, checksum: a3dc364eb9c66a1393c6417ee5dfd749 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-06-25T18:13:37Z (GMT). No. of bitstreams: 2 Lyvia Karla Cerci Ferreira Bertacchini.pdf: 1676300 bytes, checksum: a3dc364eb9c66a1393c6417ee5dfd749 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-10 / Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Estado do Paraná (FA) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The aim of this research was to compare the behavior of different thicknesses of bulk fill composite resins by analyzing the microhardness at the top and bottom of specimens (SP), the effect of aging with acid solution (ethanol / water) and fluorescence evaluation. 135 SP were fabricated with thicknesses of 2, 3 and 4 mm subdivided into 5 groups (n = 27): Z35; Aura; Tetric; SureFil; Filtek Bulk Fill (FBF). Each SP was photoactivated by LED light for 20 seconds. The microhardness test was performed after 24 hours and 30 days (ethanol / water solution) on both top and bottom surfaces. Fluorescence analysis was performed with the aid of a dark chamber by three calibrators: low, medium and high. The microhardness data were submitted to the factorial ANOVA test for Repeated Measures, followed by the LSD-Fisher follow-up test. Fluorescence by the LSD-Fisher Test. After 24h the microhardness was higher at the top in the thickness of 2mm: TETRIC and FBF, 3mm: Z350, TETRIC and FBF, 4mm: Z350, AURA, TETRIC and FBF. After aging the highest values in the bottom: 2mm: TETRIC and FBF, 3mm: AURA and TETRIC, in the 4mm: AURA was significantly higher than the first average. (p <0.05). It was possible to close that the larger the thickness, the greater the difference of the microhardness between the top and bottom surfaces. With regard to fluorescence, TETRIC (BF) was the only composite resin that did not have significantly altered values with increasing thickness. Aging in ethanol / water solution increased the microhardness values of some TETRIC, FBF and AURA composite resins. / O objetivo desta pesquisa foi de comparar o comportamento de diferentes espessuras de incrementos das resinas compostas tipo bulk fill, por meio da análise da microdureza no topo e na base de corpos-de-prova (CP), efeito do envelhecimento com solução ácida (etanol/água) e a avaliação da fluorescência Foram confeccionados 135 CP com espessuras de 2, 3, e 4mm subdivididos em 5 grupos (n=27): resina Z350;Aura bulk fill (AURA); Tetric bulk fill (TETRIC); SureFil bulk fill (SDR). ; Filtek bulk fill (FBF). Cada CP foi fotoativado por aparelho de luz Led durante 20 segundos. O teste de microdureza foi realizado após 24 horas e 30 dias (solução etanol/água) tanto na superfície do topo como na base. A análise da fluorescência foi realizada com auxílio de uma câmara escura por três avaliadores calibrados como: baixa, média e alta. Os dados de microdureza foram submetidos ao teste ANOVA fatorial para Medidas Repetidas, seguido pelo teste de acompanhamento de LSD-Fisher. A fluorescência pelo teste Teste LSD-Fisher. Após 24hs a microdureza foi maior no topo na espessura de 2mm: TBF e FBF, 3mm: Z350, TBF e FBF, 4mm: Z350, ABF, TBF e FBF. Após o envelhecimento os maiores valores na base: 2mm: TBF e FBF, 3mm: ABF e TBF, na de 4mm: ABF foi significativamente maior do que a média inicial. (p<0,05). Foi possível concluir que quanto maior a espessura, maior a diferença da microdureza entre a superfície de topo e base. Com relação a fluorescência a TBF foi a única resina composta que não teve os valores alterados de forma significativa com o aumento da espessura. O envelhecimento em solução etanol/água aumentou os valores de microdureza de algumas resinas compostas TBF, FBF e ABF.
6

Avaliação da resistência de união em reparos entre resinas compostas bulk fill, bulk fill flow e nanoparticulada envelhecidas / Repair bond strength evaluation between bulk-fill restorative composites to bulk-fill flow restorative composites and to nano-restorative materials aged

Donini, Emerson Delazari 03 March 2017 (has links)
Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2018-06-25T20:29:13Z No. of bitstreams: 2 Emerson Delazari Donini.pdf: 1027762 bytes, checksum: 9ec4a6537f9edea3f41fdaf4d3b4ce16 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-06-25T20:29:13Z (GMT). No. of bitstreams: 2 Emerson Delazari Donini.pdf: 1027762 bytes, checksum: 9ec4a6537f9edea3f41fdaf4d3b4ce16 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-03 / Repairing on composite resin restorations can be a conservative alternative to remedy restoration failures as it preserves parts of the tooth that would normally be removed during a complete exchange. The objective of this work was to evaluate the bond strength of post-repair and aging composite resins in different solutions (distilled water, 75% water-alcohol and 0.02N nitric acid). Five composite resins were used, being a conventional resin (Z350) and four bulk fill Filtek Bulk fill (FBF), Filtek Bulk Fill Flow (FBFF), Surefill SDR Flow (SURE) and Opus Bulk Fill Flow (OPUS). Specimens 2x2x5 mm were prepared in prefabricated silicone molds and aged for 30 days, after which the resins were treated with a surface treatment and soon after the repair, becoming a CP with 2x2x10mm. The repairs were performed in the same silicone mold by combining all the resins in the sample, forming 75 groups (n = 10), and immersed again for 30 days in the evaluated solutions. After, the CPs were submitted to the tensile test with the machine DL-200 MF - Emic DL line. The mean values obtained for each CP were submitted to the Kruskall-Wallis test, followed by Dunn's post-test (p <0.05). According to the experimental methodology for Z350 aged in distilled water, the repairs made with the Z350 itself (5.82 + 2.10) and the FBFF (5.88+3.06) showed no statistical differences. For the repairs between FBF (7.44 + 1.68) and OPUS (7.25 + 2.85) there were no statistically significant differences, however, they were higher than SURE (3.59 + 1.57). In 75% water/alcohol solution, all repairs made on the Z350 base were statistically similar. For the 0.02N nitric acid solution and for the Z350 base, the repairs with FBFF (4.37+1.08) and SURE (4.44+1.29) showed no differences between themselves and with FBF (3,37+0.54) and OPUS (5.43+1.21), but were higher than those with Z350 (2.27 + 0.61). When the base was FBF and the solution to distilled water, repairs with FBF (4.90 + 1.98), FBFF (5.50 + 1.56) and SURE (6.08 + 2.01) did not show Differences. Repairs with OPUS were higher (7.32 + 1.74) compared to Z350 (3.82 + 1.85). FBF as a base in the 75% water / alcohol solution and 0.02N nitric acid the repairs showed no differences between them. For the FBFF base in the distilled water, the repair with the same FBFF (7.64 + 2.86) showed no differences with the other resins. (3,63 + 2,86), SURE (7,25 + 3,03), and OPUS (6,83 + 2,40) compared to the bulk fill flow resins, FBFF (7,64 + 2,86). Which did not show significant differences between them. For the 75% water / alcohol solution there were no significant differences between the repairs compared to each other. For the 0.02N nitric acid solution, there were no statistically significant differences when comparing the Z350, FBFF and OPUS resins with each other. The results were higher for SURE (9.93+3.91) when compared to FBF (5.67+1.83) both as repair. For the SURE base in the distilled water solution, there were no significant differences between all the repairs. In the 75% water / alcohol solution, for repairs with Z350 (1.55+067), FBF (2.24+1.09), SURE (2.37+0.85) and OPUS (2.13+0.75) were not different from each other, but were better than the FBFF (2.76+0.73), and the FBF (2.24+1.09) was not different when compared to the others. In the 0.02N nitric acid solution, all repairs were statistically similar to each other. For OPUS as a base, in the distilled water solution, repairs with SURE (3.20+0.67) and OPUS (4.09+1.12) were similar to each other. The Z350 (2.83+1.36) and FBF (2.73+0.94) showed no significant differences among themselves, but compared to the FBFF resin (5.04+1.27) had worse results than this. In 75% water/ethanol solution and nitric acid there were no statistically significant differences between the resins used in the repair. According to the results obtained, it was possible to verify that, in the majority of the comparisons made among the composite resins evaluated in this study, the nanoparticulate resin presented the worst values of bond strength when used as repair. On the other hand, the bulk fill composites presented the best behavior when used as repair. / Os reparos em restaurações em resina composta podem ser uma alternativa conservadora para solucionar falhas de adaptação das mesmas, pois preserva partes do dente que normalmente seriam removidas durante uma troca completa. O objetivo desse trabalho foi avaliar a resistência de união das resinas compostas pós-reparo e envelhecimento em diferentes soluções (água destilada, água/álcool 75% e ácido nítrico 0,02N). Foram utilizadas cinco resinas compostas, sendo uma resina nanoparticulada (Z350) e quatro resinas bulk fill (Filtek Bulk fill (FBF), Filtek Bulk Fill Flow (FBFF), Surefill SDR Flow (SURE) e Opus Bulk Fill Flow (OPUS)). Foram confeccionados corpos de prova (CP) de 2x2x5 mm em molde de silicone pré-fabricado e envelhecidas por 30 dias, após esse período as resinas receberam o tratamento de superfície e logo após o reparo, tornando-se um CP com 2x2x10mm. Os reparos foram realizados no mesmo molde de silicone através da combinação entre todas as resinas da amostra, formando 75 grupos (n=10), sendo imersas novamente por 30 dias nas soluções avaliadas. Após, os CP foram submetidos ao teste de tração com a máquina DL-200 MF – Emic linha DL. Os valores médios obtidos para cada CP foram submetidos ao teste de Kruskall Wallis, seguido do pós-teste de Dunn, (p < 0,05). De acordo com a metodologia experimental para a base de Z350 envelhecida em água destilada, os reparos feitos com a própria Z350 (5,82+2,10) e com a FBFF (5,88+3,06) não houve diferenças estatísticas significantes. Para os reparos entre a FBF (7,44+1,68) e OPUS (7,25+2,85) não houve diferenças estatísticas significantes, porém elas foram superiores à SURE (3,59+1,57). Na solução água/álcool 75%, todos os reparos feitos na base Z350 mostraram-se semelhantes estatisticamente. Para a solução de ácido nítrico 0,02N e para a base de Z350, os reparos com a FBFF (4,37 +1.08) e SURE (4,44+1,29) não mostraram diferenças entre si e com as FBF (3,37+0,54) e OPUS (5,43+1,21), mas foram superiores aos reparos com a Z350 (2,27+0,61). Quando a base foi a FBF e a solução a água destilada, os reparos com FBF (4,90+1,98), FBFF (5,50+1,56) e SURE (6,08+2,01) não mostraram diferenças às demais. Reparos com a OPUS (7,32+1,74) foram superiores, comparados à Z350 (3,82+1,85). FBF como base na solução de água/álcool 75% e ácido nítrico 0,02N os reparos não mostraram diferenças entre si. Para a base de FBFF na água destilada, o reparo com a mesma FBFF (7,64+2,86) não mostrou diferenças com as demais resinas. Z350 (3,53+1,55) quando comparada às resinas bulk fill flow, FBFF (7,64+2,86), SURE (7,25+3,03) e OPUS (6,83+2,40), não mostraram diferenças significantes entre si. Para a solução água/álcool 75% não houve diferenças significantes dos reparos comparados entre si. Para a solução de ácido nítrico 0,02N, não houve diferenças estatisticamente significantes quando se comparou as resinas Z350, FBFF e OPUS entre si e as demais. Os resultados foram superiores para a SURE (9,93+3,91) quando se comparou com a FBF (5,67+1,83) ambas como reparo. Para a base SURE na solução de água destilada, não houve diferenças significantes entre todas nos reparos. Na solução de água/álcool 75%, para os reparos com Z350 (1,55+067), FBF (2,24+1,09), SURE (2,37+0,85) e OPUS (2,13+0,75) não houve diferenças entre si, mas foram melhores que a FBFF (2,76+0,73), e a FBF (2,24+1,09) não foi diferente quando comparada às demais. Na solução de ácido nítrico 0,02N, todos os reparos foram estatisticamente semelhantes entre si. Para a OPUS como base, na solução de água destilada, os reparos com a SURE (3,20+0,67) e OPUS (4,09+1,12) foram semelhantes entre si e às demais. A Z350 (2,83+1,36) e FBF (2,73+0,94) não mostraram diferenças significantes entre si, mas comparadas à resina FBFF (5,04+1,27) tiveram piores resultados em relação a esta. Em solução de água/etanol 75% e ácido nítrico não houve diferenças estatisticamente significantes entre as resinas utilizadas no reparo. De acordo com os resultados obtidos foi possível verificar que, na maioria das comparações realizadas entre as resinas compostas avaliadas nesse estudo, a resina composta nanoparticulada apresentou os piores valores de resistência a união quando utilizada como reparo. Já as resinas compostas bulk fill apresentaram na maioria das comparações realizadas o melhor comportamento quando utilizada como reparo.
7

Micro-hardness and depth of cure of dental bulk-fill composites

Abughufa, Hajer January 2015 (has links)
Magister Scientiae Dentium - MSc(Dent) / Resin composite is one of the most commonly used materials in restorative dentistry. However, it has undergone continuous developments like changes in the fillers and initiators. One such improvement is the new bulk-fill composites which are materials intended for bulk placement up to 4mm. However, an optimum polymerization to the full depth of the restoration i.e. complete depth of cure is of utmost importance in order to obtain proper mechanical and physical properties of resin composites. Aim: The aim of this study was to measure the surface hardness of the top and bottom surfaces of the composites and to determine the depth of cure of bulk-fill composites using two different types of light curing units. Material and methods: A total of 160 specimens were used in this study: four bulk-fill composite were used of which two were conventional viscosity bulk-fill composites namely, Tetric N Ceram (Ivoclar Vivadent) and SureFil bulk-fill composite (Densply Caulk) and two were low viscosity flowable bulk-fill composites namely, SDR flowable (Densply Caulk) and Filtek bulk-fill flowable restorative (3M ESPE). Two different curing light were used namely, LED (Elipar Freelight, 3M ESPE) at 1500mW/cm2 and a Quartz Tungsten Halogen (QTH) curing unit (Megalux CS, Megadenta, Germany) at 600 mW/cm2. To evaluate micro-hardness, Vickers hardness at top and bottom of each sample was measured immediately after light curing and after 24 hours post curing using a Zwick micro-hardness machine load 300g/15 seconds. The mean hardness values obtained from the top and the bottom surface of each material were used to compare the micro-hardness of the various materials. The mean values obtained from the bottom surface were compared to the respective values of the top surface of each material (bottom/top ratio) and used to calculate the depth of cure. Results: The micro-hardness test showed a significant difference between the four materials (ANOVA, p<0.05) immediately after curing and after 24 hours post curing. The material with the greatest micro-hardness was SureFil followed by Tetric N Ceram, Filtek bulk-fill flowable and SDR flowable respectively. The material with the greatest depth of cure was Filtek bulk-fill flowable followed by SDR flowable, Tetric N Ceram and SureFil. When the curing lights were compared the Light Emitting Diode Curing Unit (LED) obtained significantly better depth of cure compared to Quartz Tungsten Halogen Light Curing Units. The LED curing light showed greater micro-hardness values than the QTH curing light except for Tetric N Ceram where the QTH curing showed more hardness values than the LED curing light. For all materials, the surface hardness and depth of cure values increased when tested 24hrs after light curing. Conclusion: There was a difference in the micro-hardness values between the four materials where the conventional viscosity materials showed greater surface hardness values than the low viscosity materials but the depth of cure compared to the bulk-fill flowable LED curing lights showed higher hardness values than QTH curing light except for Tetric N Ceram. Depth of cure ratios were found to be lower than 0.80 for all composite types, however the flowable bulk-fill materials showed higher depth of cure than the conventional viscosity bulk-fills. In general LED curing light produced better hardness and depth of cure values than QTH curing light. The low micro-hardness values for the bulk-fill flowable composites and the inadequate polymerization raises a concern regarding placing these materials in bulk. In such cases, the flowable bulk-fills should be protected with a conventional composite "covering or capping" especially in posterior teeth and in deeper cavities. Furthermore, bulk-fill composites should be used in layering incremental technique to ensure sufficient depth of cure.
8

Cuspal Deflection in Premolar Teeth Restored with Bulk-Fill Resin-Based Composite Materials

Elsharkasi, Marwa M.O. January 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Objectives: To investigate the effect of bulk-fill resin based composite materials on cuspal deflection in large slot mesio-occlusal-distal cavities (MOD) in premolar teeth. Methodology: Thirty-two sound maxillary premolar teeth with large slot MOD cavities were distributed to four groups (n=8). Three groups were restored with bulk-fill resin composite materials (Tetric EvoCeram, x-tra fil, and Sonic Fill, respectively) in a single increment. The conventional composite group, Filtek Z100, was used to restore the cavities in 2mm increments. Cusp deflection was recorded post irradiation using a Nikon measurescope UM-2 (Nikon, Tokyo, Japan), by measuring the changes in the bucco-palatal width of the premolar teeth at 5 minutes, 24 hours, and 48 hours after completion of the restoration. The cuspal deflection was obtained by recording the difference between the baseline measurements and the other measurements for each tooth. Results: Cuspal deflection was significantly higher in Conventional Composite than in Tetric EvoCeram Bulk Fill (p=0.0031), x-tra Fil Bulk (p=0.0029), and SonicFill Bulk (p=0.0002). There was no significant difference in cuspal deflection for Tetric EvoCeram Bulk, X-tra Fil Bulk, and SonicFill Bulk Composites. Conclusions: All the investigated bulk-fill resin composites exhibited cuspal deflection lower than conventional resin composite. One of the aims of research and studies on the resin composite materials is improving their clinical longevity, and simplifying their use. For that purpose bulk-fill materials are considered promising materials and further clinical studies should be conducted.
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Análise comparativa e caracterização das bolhas de ar em dois modelos de técnicas restauradoras: incremental e bulk fill / Comparative analysis of voids quantity in two restorative techniques: incremental and bulk fill

Díaz, Carolina Alejandra Pardo 05 December 2018 (has links)
Os materiais restauradores estão evoluindo rapidamente e novas técnicas de inserção do compósito na cavidade restauradora estão sendo propostos. Dependendo da técnica, poderá ocorrer maior ou menor formação de bolhas na restauração final. A incorporação de bolhas entre as camadas do material restaurador pode gerar uma maior degradação da restauração em virtude da menor obtenção de propriedades físico-mecânicas do material. Assim, a necessidade de estudos sobre a prevalência de bolhas em restaurações confeccionadas com diferentes técnicas de inserção se faz necessária para a melhor compreensão do uso e do manuseio dos materiais. O objetivo desse trabalho foi analisar a ocorrência de bolhas e o volume de espaços presentes no interior de restaurações com resina composta, inserida na cavidade dental através das técnicas restauradoras: incremental e bulk fill. Quarenta e oito dentes molares humanos (n=24, duas restaurações por dente) foram selecionados e, nestes, foram confeccionados dois preparos por dente, um em cada região proximal, com profundidade de 4mm, largura de 4mm e distância axio-proximal de 2mm. Posteriormente, foram restaurados de acordo com os grupos: FiltekTM One Bulk Fill Restorative (FOB; 3M Oral Care); FiltekTM Z350 XT (FXT; 3M Oral care); FiltekTM Bulk Fill Flowable Restorative (FBF+FXT; 3M Oral care) e FiltekTM Z350 XT Flow (FF+FXT; 3M Oral care) . As resinas fluidas foram cobertas com a resina FiltekTM Z350 XT (3M Oral Care). Após 24 horas, os dentes restaurados foram submetidos à ciclagem térmica (5.000 ciclos) e posteriormente foi realizada a Tomografia de Coerência Ótica (OCT). Através da análise das imagens obtidas pelo OCT foram medidos os valores de quantidade de bolhas e porcentagem de espaços presentes nas restaurações. Os dados da presença de bolhas foram analisados estatisticamente com o teste Qui-Quadrado, os dados de número de bolhas e porcentagem de espaços obtidos foram analisados com o teste de Kruskall Wallis e a comparação entre os grupos foi feita pelo método de Dunn , com nível de significância de 5%. FF+FXT, apresentou bolhas em todas as restaurações e foi significativamente maior quando comparado a FXT (p=0,015). FF+FXT apresentou quantidade significativamente maior de bolhas (p<0,05) quando comparada com os outros três grupos. FBF+FXT apresentou a maior porcentagem de porosidade, devido ao maior tamanho de bolhas, porém esta porcentagem foi significantemente maior apenas quando comparada com FXT (p<0,05). Todos os grupos apresentaram bolhas. As técnicas restauradoras que apresentaram o pior desempenho, considerando o número de bolhas e a porcentagem de porosidade, foram aquelas realizadas com resina composta fluída. Não houve diferença estatisticamente significante quanto ao número de bolhas e à porcentagem de espaços entre as restaurações confeccionadas somente com resinas de alta viscosidade para as diferentes técnicas utilizadas neste estudo. / Dental restorative materials are quickly evolving, and new techniques are being proposed to change the way of filling dental cavities. Depending on the technique, a different number of voids could be generated inside the restauration. The appearance of these voids between layers of resin composite can significate a greater degradation of the material determined by low mechanical and physical properties. Therefore, to investigate voids prevalence at different restorative techniques is needed, in order to get a better understanding of the resin composites and their best handling. The objective of this project was to analyze the voids frequency inside and between the layers of the resin composite, filling class II cavities using incremental technique and bulk fill technique. Forty eight human teeth (n=24, two restorations per tooth) were selected and two cavities per tooth were made, one per each proximal area, 4mm of depth, 4mm height and 2mm of axio-proximal distance. After, they were divided in four groups and restored using FiltekTM One Bulk Fill Restorative (FOB; 3M Oral Care); FiltekTM Z350 XT (FXT; 3M Oral care); FiltekTM Bulk Fill Flowable Restorative (FBF+FXT; 3M Oral care) e FiltekTM Z350 XT Flow (FF+F; 3M Oral care), handled according to manufacturer instructions. Flowable resin composite was covered with FiltekTM Z350 (3M Oral Care). 24 hours later, thermocycling was conducted (5,000 cycles) and later Optical Coherence Tomography was performed. By analyzing the OCT images, number of voids and percentage of void volume were calculated. Presence of voids were analyzed by Chi-squared test, number of voids and percentage of void volume were analyzed by Kruskall Wallis test, and comparisons were performed by Dunn Method, at significance level of 5%.. FF+FXT had voids in all the restorations of the group, and it was significantly greater when compared with FXT (p=0.015). FF+FXT had statistically significant more number of voids (p<0.05) when compared with the others 3 groups. FBF+FXT had the highest percentage of voids volume, because the size of its voids, but this percentage was significantly different only when compared with FXT (p<0,05). All groups had voids. Restorative techniques that presented worst performance, considering number of voids and percentage of voids volume, were the ones made with flowable resin composite. Non statistical differences referred to a number of voids, neither percentage of voids volume among restorations made using only high viscosity resin.
10

Estudo de propriedades de resinas compostas bulk fill / Study of properties of bulk-fill resin composites

Rodrigues Júnior, Ezequias Costa 20 January 2016 (has links)
Diante da evolução da composição das resinas compostas e do lançamento de compósitos do tipo bulk fill, faz-se necessário o estudo do desempenho dessa nova classe de materiais. Para isso, o presente estudo teve como objetivo avaliar propriedades como grau de conversão (GC) , dureza Knoop (KHN), resistência à flexão (RF) e tenacidade à fratura (KIC) de sete compósitos bulk fill (EverX Posterior, EXP; Filtek Bulk Fill Flow, FBFF; Fill-Up!, FU; SonicFill, SF; Surefil SDR, SDR; Tetric EvoCeram Bulk Fill, TECBF; Venus Bulk Fill, VBF) e um compósito nanohíbrido convencional (Charisma Diamond, CD). De forma complementar, foi realizado tratamento térmico a 170 °C por 10 minutos para melhor compreensão do comportamento desses materiais quanto ao potencial de conversão e à indução de tensões na interface carga/matriz. A avaliação do GC (n=3) foi realizada através de espectroscopia FTIR, a leitura da dureza Knoop foi realizada nas superfícies do topo e da base (n=3), e os ensaios de RF de três pontos (n=10) e KIC (n=10) em máquina de ensaios universais. Os resultados obtidos foram submetidos à analise de variância (complementados pelo teste de Tukey) ou teste Kruskal-Wallis, com nível de significância de 5%. A análise do GC (%) revelou diferença entre os materiais testados, sendo que todas as resinas bulk fill apresentaram valores maiores que a resina convencional: SF (75,7) > VBF (66,7) = EXP (66,4) = SDR (62,8), sendo esta também semelhante a FU (60,0); FU, TECBF (56,6), FBFF (56,6) e CD (54,5) apresentaram conversão semelhante. Os valores de KHN variaram de acordo com o material e com a superfície: apenas SF apresentou KHN semelhante (na superfície do topo) a CD, entretanto não foi possível realizar a leitura da superfície da base deste último material; SF, TECBF e FBFF apresentaram valores de KHN diferentes nas superfícies topo e base; EXP, FU, SDR e VBF mantiveram os valores de dureza do topo semelhantes à superfície da base. Para a RF (MPa), os resultados variaram de acordo com o material: EXP (122,54) = SF (101,09) = CD (99,15), sendo estes dois últimos semelhantes a FU (83,86) e TECBF (82,71), os quais não diferiram da resina SDR (65,18); esta última também mostrou comportamento semelhante a FBFF (60,85) e VBF (59,90). Quanto ao KIC (MPa.mm0,5), EXP (3,35) apresentou o maior valor, semelhante a SF (2,42), que por sua vez também foi igual ao compósito convencional CD (2,01); CD apresentou KIC semelhante a SDR (1,74); SDR = VBF (1,59) = TECBF (1,57); TECBF, FU (1,54) e FBFF (1,37) apresentaram valores semelhantes. Na dependência do material, o tratamento térmico aumentou os valores dos parâmetros estudados, apontando limitações da reação de polimerização dos compósitos estudados. Com base nos resultados obtidos, podese concluir que: resinas bulk fill apresentam elevado GC, superior à resina convencional estudada; a nova classe de materiais restauradores é capaz de polimerizar em profundidade e alguns materiais apresentam KHN semelhantes no topo e na base de espécimes de 4 mm de profundidade; RF e KIC variaram de acordo com o material, e o compósito EXP apresentou os maiores valores para ambos os testes. / Facing the evolution of the resin composites and the release of the bulk-fill composite type, it is necessary to study the performance of this new class of materials. For this, the present study aimed to evaluate properties such as degree of conversion (DC), Knoop hardness (KHN), flexural strength (FS) and fracture toughness (KIC) of seven bulk-fill composites (EverX Posterior, EXP; Filtek Bulk Fill Flowable, FBFF; Fill-Up!, FU; SonicFill, SF; Surefil SDR, SDR; Tetric EvoCeram Bulk Fill, TECBF; Venus Bulk Fill, VBF) and a conventional nanohybrid composite (Charisma Diamond, CD). Complementarily, heat treatment was performed at 170 °C for 10 minutes for better understanding the behavior of these materials. Evaluation of DC (n=3) was performed by FTIR spectroscopy, the evaluation of Knoop hardness was made on the top and bottom surfaces (n=3), and three point bending test (n=10) and KIC (n=10) were evaluated on a universal testing machine. The results were submitted to analysis of variance (complemented by Tukey test) or Kruskal-Wallis test with 5% significance level. Analysis of DC (%) revealed differences between tested materials, and all bulk-fill resins had higher values than the conventional resin: SF (75.7) > VBF (66.7) = EXP (66.4) = SDR (62.8), which was also similar to FU (60.0); FU, TECBF (56.6), FBFF (56.6) and CD (54.4) showed similar conversion. KHN values showed variations according to the material and the surface: only SF showed a similar KHN (on the top surface) to CD, however it was not possible to read the bottom surface of this latter material; SF, TECBF and FBFF presented different KHN values on the top and bottom surfaces; EXP, FU, SDR and VBF maintained top and bottom similar hardness values. For FS (MPa), the results varied according to the material: EXP (122.54) = SF (101.09) = CD (99.15), the latter two being similar to FU (83.86) and TECBF (82.71), which did not differ from SDR resin (65.18); the latter showed similar behavior to FBFF (60.85) and VBF (59.90). As for KIC (MPa.mm0.5), EXP (3.35) had the highest value, similar to SF (2.42), which in turn was also equal to the conventional composite CD (2.01); CD presented KIC similar to SDR (1.74); SDR = VBF (1.59) = TECBF (1.57); TECBF, FU (1.54) and FBFF (1.37) were similar. Depending on the material, heat treatment increased the values of the parameters, pointing limitations of polymerization reaction of the studied composites. Based on these results, it can be concluded that: bulk fill resins have high DC, higher than the conventional resin studied; the new class of restorative materials is capable of polymerizing in depth and some materials exhibited similar KHN at the top and bottom surfaces of 4 mm depth specimens; FS and KIC varied according to the material, and the EXP composite showed the highest values for both tests.

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