Orientador: Marcelo Giannini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-13T02:04:38Z (GMT). No. of bitstreams: 1 DiFrancescantonio_Marina_M.pdf: 16720831 bytes, checksum: ce2d1ee161bca05d6b15b3e0a9eaeedd (MD5) Previous issue date: 2009 / Resumo: As propriedades mecânicas dos cimentos resinosos são influenciadas pelo tipo e composição da matriz resinosa, tipo e tamanho das partículas de carga, modo e grau de conversão dos monômeros em polímeros, e a viscosidade é uma propriedade que está intimamente ligada a esses fatores. Os objetivos deste estudo foram avaliar a influência da viscosidade (alta e baixa) e modo de polimerização (polimerização dual e autopolimerizado) de cimentos resinosos duais (Nexus 2/ Kerr, Corp e Variolink II/ Ivoclar-Vivadent): na resistência de união da restauração à dentina (RU), no grau de conversão (GC) e na resistência flexural biaxial (RFB). Para o teste de RU, substratos dentinários de cinqüenta e seis terceiros molares humanos foram utilizados para o ensaio de microtração através da cimentação de uma peça protética do material de resina composta indireta e estes foram foto-ativados ou não segundo cada grupo experimental. Após 24 horas, os dentes foram secionados para obter espécimes em forma de palitos (de área de secção transversal de 1.0 mm²), que foram testados em tração a uma velocidade de 0,5 mm/ mim (4411/Instron). Os resultados foram analisados por ANOVA 3 fatores e teste Tukey (p=0,05). Para a análise do GC, os cimentos foram aplicados na superfície da unidade de reflectância total atenuada acoplada ao espectrômetro infravermelho (Nicolet Instrument Corp, Madson, Wisconsin, EUA) sendo foto-ativados ou não. Espectros foram obtidos após 5 minutos e 24 horas. O cálculo do grau de conversão foi realizado através da análise da mudança na proporção entre as alturas dos picos das ligações duplas de carbono alifática e aromática. Os dados foram submetidos a ANOVA 3 fatores e teste de Tukey (p=0,05). Para o ensaio de RFB, noventa e seis discos de cimentos resinosos (0,5mm de espessura/ 6mm de diâmetro) foram preparados utilizando moldes de silicone de adição (n=12) e foram foto-ativados ou não segundo os grupos experimentais. Após 5 dias, os discos foram testados em dispositivos de ensaio de flexão biaxial em máquina de ensaio universal (1,27 mm/min, Instron 5844) e os dados analisados estatisticamente por ANOVA 3 fatores e teste Tukey(p=0,05). Para a RU, a polimerização dual (foto + autopolimerização) aumentou significantemente os valores médios para os cimentos resinosos em baixa viscosidade para ambos os cimentos resinosos duais utilizados no estudo. Em relação o GC, a foto-ativação e quando o GC foi mensurado após 24 horas, aumentaram significativamente o GC para ambos os cimentos resinosos. A versão em baixa viscosidade apresentou maior GC que os em alta viscosidade, para as duas formas de polimerização. No teste RFB, a foto-ativação aumentou significantemente a resistência e módulo de flexão. A versão em alta viscosidade quando foto-ativada mostrou maior resistência flexural que em baixa viscosidade, enquanto a viscosidade não alterou os valores médios de módulo flexural. Pode-se concluir que a foto-ativação é necessária durante a cimentação de restaurações indiretas, para garantir adequadas propriedades físico-químicas, e a utilização de cimentos resinosos em diferentes viscosidades pode modificar os valores médios de RFB, GC e RU à dentina. / Abstract: The mechanical properties of resin cements may be influenced by the type and monomer composition, type and filler size, mode, and degree of conversion, which are all associated with resin viscosities. The aim of this study was to evaluate the influence of resin cement viscosity (high and low) (Nexus 2/ Kerr, Corp and Variolink II/ Ivoclar-Vivadent) and the curing mode (dual and chemical activation) on the bond strength to dentin, on the degree of conversion and biaxial flexural strength. For microtensile bond strength test, two bonding agents and their respective resin cement, occlusal dentin surfaces of fifty-six human third molars were used for the testing and the resin cements were applied to pre-cured resin composite discs, which were fixed to dentin surfaces, simulating an indirect restoration. The restored teeth were either light-activated or allowed to self-cure, according to experimental groups. After 24 hs, the teeth were sectioned to obtain bonded beams specimens (1.0 mm²). Each specimen was tested in tension at a crosshead speed of 0.5 mm/min (4411/Instron). Data (MPa) was analyzed by 3- way ANOVA and Tukey's Tukey's test (p=0.05). To evaluate the degree of conversion, the resin cements were applied to surface of a horizontal attenuatedtotal- reflectance unit (Nicolet Instrument Corp, Madson, Wisconsin, EUA) and were polymerized using one of two conditions: self-cure (SC) or direct light exposure (600 mW/cm2, XL3000/3M ESPE) and infrared spectra were obtained after 5 minutes and 24 hours. The degree of conversion was calculated using standard techniques of observing changes in aliphatic-to-aromatic peak ratios pre- and postcuring. Data were analyzed by 3-way repeated measure ANOVA and Tukey's test (p=0.05). For the biaxial flexural strength, forty-eight resin cement discs of each product (0.5 mm thick and 6.0 mm in diameter) were created using silicon impression material molds (n=12) and were either light activated or not, according to experimental groups. After 5 days, the specimens were subjected to the biaxial flexure test in a universal testing machine (1.27 mm/min, Instron 5844) and the data ware statistically analyzed by 3-way ANOVA and Tukey's post-hoc test (p=0.05). For bond strength testing, the dual curing mode increased the bond strength for the low viscosity resin cements for both dual resin cement used in this study. For the degree of conversion, the light activation, after 24h, significantly increased the degree of conversion for both resin cements, and the low viscosity version from dual cure or self-cured groups exhibited higher degree of conversion than high viscosity version. Regarding biaxial flexural strength, the light-activation significantly increased flexural strength and modulus, and the high viscosity versions of dual cure groups exhibited higher flexural strength than their low viscosity versions, while the viscosity of resin cements did not influence the modulus. In conclusion, the light-activation of dual resin cements is required in indirect restorations, to provide proper mechanical and chemical properties, and the use of resin cements with different viscosities may change the bonding biomechanical characteristics of indirect restorations. / Mestrado / Dentística / Mestre em Clínica Odontológica

Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2018-10-03T19:48:30Z No. of bitstreams: 2 Patricia_Macedo2018.pdf: 792975 bytes, checksum: a12fcccb5877a843f32aabd7aa561149 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-10-03T19:48:30Z (GMT). No. of bitstreams: 2 Patricia_Macedo2018.pdf: 792975 bytes, checksum: a12fcccb5877a843f32aabd7aa561149 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-26 / The purpose of this study was to evaluate, in vitro, the effect of ozonated water as a cleaning solution on the bond strength of glass fiber pins. Ninety-eight bovine roots were used, divided randomly into 7 groups, according to the irrigation and dentin cleaning solution: HP/HP – 2,5% sodium hypochlorite, AD/AD - distilled water;; CHX/CHX - 2% chlorhexidine; AO/AO - ozonated water 4 ppm; HP / AD – 2,5% sodium hypochlorite and distilled water; HP / CHX - 2.5% sodium hypochlorite and 2% chlorhexidine and, HP / AO – 2,5% sodium hypochlorite and 4 ppm ozonated water. The root canals were prepared endodontically according to the irrigating solutions of each group and stored in distilled water. After 7 days, they were cleared and cleaned according to cleaning solutions. The fiberglass pins were cemented using self-adhesive cement. After 7 days of cementation, the roots were sectioned (6 discs each) and submitted to the push-out test. The analysis of the type of fracture was done with a stereoscopic magnifying glass of 4,5x. Data were analyzed statistically by ANOVA and Tukey tests with a significance level of 5%. The highest mean of push-out union strength in the cervical third was obtained in the AO (11,67), HP (11,21) and HP / AO (9,71) groups, maintaining this same tendency in the middle and apical thirds. The AO and HP were the most relevant solutions in the treatment of root dentin. / O propósito deste estudo foi avaliar, in vitro, o efeito da água ozonizada como solução de limpeza sobre a resistência de união de pinos de fibra de vidro. Foram utilizadas 98 raízes bovinas n = (14), divididas aleatoriamente em 7 grupos, de acordo com a solução irrigadora e de limpeza dentinária: HP/HP - hipoclorito de sódio 2,5%; AD/AD - água destilada; CHX/CHX - clorexidina 2%; AO/AO - água ozonizada 4 ppm; HP/AD - hipoclorito de sódio 2,5% e água destilada; HP/CHX - hipoclorito de sódio 2,5% e clorexidina 2%, e HP/AO - hipoclorito de sódio 2,5% e água ozonizada 4 ppm. Os canais radiculares foram preparados endodonticamente de acordo com as soluções irrigadoras de cada grupo e armazenados em água destilada. Após 7 dias, foram desobturados e limpos de acordo com as soluções de limpeza. Os pinos de fibra de vidro foram cimentados, utilizando cimento resinoso autoadesivo. Após 7 dias da cimentação, as raízes foram seccionadas (6 discos cada) e submetidas ao teste de push-out. A análise do tipo de fratura foi feita com uma lupa estereoscópica de 4,5x. Os dados obtidos foram analisados estatisticamente pelos testes ANOVA e Tukey com nível de significância 5%. A maior média de resistência de união push-out no terço cervical foi obtida nos grupos AO (11,67), HP (11,21) e HP/AO (9,71), mantendo esta mesma tendência nos terços médio e apical. A AO e HP foram as soluções mais relevantes no tratamento da dentina radicular.

Orientador: Giselle Maria Marchi Baron / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T19:05:45Z (GMT). No. of bitstreams: 1 Palialol_AlanRodrigoMuniz_M.pdf: 12504444 bytes, checksum: a578af5941e733ad7dd18243b934355c (MD5) Previous issue date: 2013 / Resumo: O objetivo desse estudo foi avaliar a resistência de união de cimentos resinosos experimentais contendo diferentes concentrações do sal de hexafluorfosfato de difeniliodônio (DPIHFP) à cerâmica reforçada por dissilicato de lítio, com ou sem aplicação do adesivo após o uso do silano. Para isso, cinco diferentes formulações de cimento foram confeccionadas utilizando como base os monômeros Bis-GMA e TEGDMA (na proporção 1:1 em massa) e 60% em peso de partículas silanizadas de vidro de bárioalumínio- silicato. O sistema fotoiniciador foi composto por 1 mol% de canforoquinona (CQ), 2 mol% de metacrilato de dimetilaminoetil (DMAEMA) e diferentes concentrações de DPIHFP: 0; 0,25; 0,5; 1 e 2 mol%, definindo assim, cinco formulações de cimentos resinosos experimentais. Como inibidor foi acrescido à mistura uma quantidade de 0,1 mol% de hidroxitolueno butilado e 60% em peso de partículas silanizadas de vidro de bário-alumínio-silicato foram incorporadas como carga inorgânica. Diante disso, a cimentação foi realizada com ou sem a aplicação do adesivo (Adper Scotchbond Multi- Purpose - Bond) estabelecendo assim, 12 grupos (n=7), sendo avaliados os cinco cimentos experimentais formulados e um cimento comercial (RelyX ARC). Foram confeccionados 84 espécimes de cerâmica IPS e.max (10 mm de comprimento x 10 mm de largura x 3 mm de espessura) e divididos, aleatoriamente, entre os 12 grupos previamente estabelecidos. Para todos os grupos foi realizado o condicionamento ácido da cerâmica (ácido hidrofluorídrico a 10%, 20 s) e aplicação de silano (RelyX Ceramic Primer). Logo após, os espécimes foram cimentados a blocos de resina fotopolimerizável Filtek Z250 (10 mm de comprimento x 10 mm de largura x 5 mm de espessura), utilizando os diferentes cimentos de acordo com o respectivo grupo, sob carga estática de 500 g, por 1 minuto. Para os grupos com utilização de adesivo, este foi aplicado 1 minuto após a aplicação do silano, sendo fotoativado através da cerâmica com LED 3a geração (Bluephase G2) a 1200 mW/cm2 juntamente com o cimento resinoso por 60 segundos. Após armazenamento (sob umidade relativa) em estufa por 24 horas a 37oC, as amostras foram seccionadas perpendicularmente à interface de união, gerando palitos de 1 mm2 (30 palitos por bloco) que foram submetidos ao ensaio de microtração em máquina de ensaio universal EMIC com velocidade de 0,5 mm/min. Foi realizado análise do padrão de fratura em lupa estereoscópica (Leica MZ75) com aumento de 40x e uma imagem representativa de cada padrão foi realizada em microscopia eletrônica de varredura. Os dados foram analisados através de Análise de Variância a dois critérios e teste Tukey, a um nível de significância de 5%. O cimento resinoso dual RelyX ARC apresentou os maiores valores de união, para os grupos com ou sem aplicação de sistema adesivo. Nos grupos com aplicação do sistema adesivo, os cimentos experimentais não diferiram estatisticamente entre si quanto à resistência de união. Nos grupos sem aplicação de adesivo, o cimento contendo 2mol% de DPIHFP obteve os menores valores de união. A aplicação do adesivo propiciou maiores valores de união somente para os cimentos RelyX ARC e DPIHFP 2mol%. De acordo com os resultados, pode-se concluir que a adição do sal de DPIHFP não foi capaz de aumentar os valores de união dos cimentos experimentais. O sistema de dupla ativação apresentou resistência de união à cerâmica superior aos cimentos experimentais fotoativados e a aplicação do adesivo promoveu o aumento dos valores de união apenas para os cimentos RelyX ARC e DPIHFP 2mol% / Abstract: The aim of this study was to evaluate the bond strength of experimental resin cements (ERCs) containing different concentrations of Diphenyliodonium Hexafluorphosphate (DPIHFP) salt to a lithium disilicate ceramic with or without the adhesive application after silane treatment. For this purpose, five ERCs were prepared using a Bis-GMA/TEGDMA (1:1 molar ratio) base compound with a 60% mass fraction of silanated Barium-Aluminum-Silicate glass fillers. The photoinitiator system was composed by 1 mol% of camphorquinone (CQ) 2 mol% of dimethylaminoethil methacrylate (DMAEMA) and different DPIHFP concentrations of 0, 0.25, 0.5, 1 or 2 mol%, resulting in five ERCs. As an inhibitor, 0.1mol% of hydroxyl butyl toluene was used. Therefore, the fixing protocol was performed with or without the application of adhesive (Scotchbond Multi-Purpose Adper - Bond) thereby establishing, 12 groups (n = 7), evaluating the five experimental resin cements and a commercial cement (RelyX ARC). Eighty four IPS e.max Press ceramic specimens (10 mm lenght x 10 mm width x 3 mm thickness) were fabricated and randomly divided among the 12 groups previously established. All the groups were etched with 10% hydrofluoric acid for 20 seconds and silane couple agent applied on the bond surface. After that, the specimens were fixed to photoactivated composite resin Filtek Z250 blocks (10 mm lenght x 10 mm width x 5 mm thickness), using different cements according to the respective group under static load of 500 g per one minute. For groups with adhesive application, this was applied 1 minute after applying the silane being cured by a third generation LED (Bluephase G2) together with the resin cement for 60 seconds. After storage for 24 hours at 37oC, the samples were sectioned perpendicular to the bond interface to obtain 1 mm2 sectional area beams (30 beams per sample) and submitted to a microtensile bond strength test in a universal testing machine EMIC, at a crosshead speed of 0.5 mm/min. The failure mode was analyzed by a stereomicroscope (Leica MZ75) at 40x magnification and one example of each type of failure mode was analyzed in scanning electron microscopy. Data were analyzed using ANOVA two criteria (ANOVA two-way) and Tukey test at a significance level of 5%. The dual resin cement RelyX ARC showed the highest bond strength values using or not the adhesive system. In groups with adhesive system, the ERCs were not statistically different from each other on the bond strength values to ceramics. In groups without adhesive system, the 2mol% of DPIHFP resin cement obtained the lowest bond strength values. The adhesive application led to higher bond strength values only for RelyX ARC and 2mol % DPIHFP resin cements. According to results, it can be concluded that the addition of DPIHFP salt was not able to increase the bond strength values of the experimental cements. The dual activation system showed higher values of bond strength when compared to photoactivated ERCs and adhesive system protocol increased the bond strength values only for the RelyX ARC and 2mol% DPIHFP resin cements / Mestrado / Dentística / Mestre em Clínica Odontológica

Orientador: Mário Alexandre Coelho Sinhoreti / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-24T07:19:06Z (GMT). No. of bitstreams: 1 Leme_ArieneArcasTopalPaes_D.pdf: 1762862 bytes, checksum: df60c904446c386b9834989fa6847207 (MD5) Previous issue date: 2013 / Resumo: Neste estudo avaliou-se o efeito: (1) da adição de resina de troca aniônica (AER) a um cimento experimental, para reduzir a incompatibilidade entre sistemas adesivos simplificados e cimento resinoso de polimerização dupla, quando ativado quimicamente; (2) da aplicação de uma camada extra de adesivo entre o sistema adesivo simplificado e o cimento resinoso, na resistência da união, propriedades nanomecânicas da camada de cimento e micropermeabilidade na interface adesiva. Discos de resina composta foram cimentados com os sistemas adesivos ACE ALL Bond TE ([ACE] Bisco Inc.) e Scotchbond Universal ([SCU] 3M ESPE) ... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital. / Abstract: This study evaluated the effect of: (1) adding anion exchange resin (AER) to an experimental resin cement aiming to reduce incompatibility between simplified-step adhesive systems and dual-cured resin cement when chemically activated; (2) the application of an extra adhesive resin layer between the simplified adhesive system and resin cement, on the microtensile bond strength, nanomechanical properties of the cement layer and micropermeability at the adhesive layer. Resin composite discs were luted with the adhesive systems ACE ALL Bond TE ([ACE] Bisco Inc.) and Scotchbond Universal ([SCU] 3M ESPE) ... Note: The complete abstract is available with the full electronic document / Doutorado / Materiais Dentarios / Doutora em Materiais Dentários

Orientador: Mario Fernando de Goes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-27T03:08:16Z (GMT). No. of bitstreams: 1 Lima_RenallyBezerraWanderleye_M.pdf: 1436974 bytes, checksum: 1ffe21bf86f88b2af39db7e176ccc1b2 (MD5) Previous issue date: 2015 / Resumo: O objetivo deste estudo foi avaliar a resistência à flexão biaxial (RFB) de cimentos resinosos dual, submetidos a diferentes métodos de ativação e armazenados no período de 15 min, 24h e 6 meses. Os cimentos resinosos (RelyX Unicem 2 automix (autoadesivo) (RU) e Variolink II (convencional) (VL) foram manipulados e inseridos em moldes de teflon (0,5 mm de espessura x 6,5 mm de diâmetro), posicionados em superfície com temperatura controlada (35°C). Foram confeccionados 120 espécimes de cada material, os quais foram divididos em grupos de acordo com o período de armazenamento (15 min, 24h e 6 meses) (n=40) e em subgrupos de acordo com os métodos de ativação (n=10) a seguir: auto-polimerização, fotoativação direta (FD), fotoativação direta com distância de 6 mm entre a ponta do aparelho de luz e o espécime (PD) e fotoativação indireta (anteparo de resina composta de 6 mm) (FI). Os espécimes fotoativados foram expostos à luz visível por 40s (56 J/cm2). O ensaio de resistência à flexão biaxial foi realizado em uma máquina de teste universal (model 1144, Instron Corp, Norwood, MA, USA) com velocidade de 1.27 mm/min, após cada período de armazenamento Os valores de RFB foram submetidos à análise de variância (ANOVA) de 3-fatores e teste de Tukey post-hoc (p=0,05). A análise de variância demonstrou significativa interação entre os materiais, período de armazenamento e método de ativação (p< 0.0001). Os valores de RFB pelo método de auto-polimerização foram estatisticamente inferiores em relação aos outros métodos de ativação, em todos os períodos de armazenamento, para ambos os cimentos. O método FI apresentou valores de RFB estatisticamente inferiores em relação ao método FD no período de 15 min para ambos os cimentos e em 24 h apenas para o RU. Para ambos os cimentos, os valores de RFB para o método de auto-polimerização foram estatisticamente inferiores no período de 15 min em relação a 6 meses e o método FD apresentou valores de RFB estatisticamente superiores no período de 15 min em relação a 6 meses. Os valores de RFB em 6 meses foram estatisticamente inferiores em relação a 24 h nos métodos de auto-polimerização e FD para o RU. Para o VL os valores de RFB na maioria dos métodos de ativação foram estatisticamente inferiores em 6 meses em relação a 24 h. No período de 24h, o VL apresentou valores de RFB estatisticamente superiores ao RU em todos os métodos de ativação. A fotoativação foi fator essencial para a obtenção da resistência à flexão imediata (15 min) para os dois materiais. A fotoativação indireta reduziu a RFB para ambos os cimentos no período de 15 min e apenas para o RU no período de 24 h. O período de armazenamento de 6 meses, diminuiu a RFB, para a maioria dos métodos de ativação. O cimento resinoso convencional sempre apresentou valores de RFB maiores ou iguais ao cimento resinoso autoadesivo. A luz é um fator primordial para a obtenção da RFB dentro dos padrões aceitáveis, independente do período de armazenamento / Abstract: The aim of this study was to evaluate the biaxial flexural strength (RFB) of dual-cure resin cements when submitted to different activation methods and after storage periods of 15 min, 24 hours and 6 months. One hundred-twenty disk-shaped specimens for each cement (RelyX Unicem 2 automix, self-adhesive (RU) and Variolink-II, conventional (VL) were made in Teflon molds (0.5mm thickness x 6.5mm diameter) placed under controlled temperature surface (35ºC),then were polymerized as follows (n=10): self-curing method, directly light-cured (DL), light-cured with a distance of 6 mm between the light tip and the specimen (PD), and indirectly light-cured (IL) (using a 6mm composite resin barrier). Light-cured specimens were exposed for 40 seconds to visible light (56 J / cm2). Forty disc-shaped specimens by material from each storage group (15-minutes, 24 hours and 6-months) were placed into a biaxial-flexure jig and a vertical load was applied (1.27mm/min) on a universal testing machine (model 1144, Instron Corp., Norwood, MA) until failure. The original RFB values were subjected to three-way ANOVA statistical analysis and Tukey post-hoc test (p = 0.05). ANOVA revealed a significant interaction between materials, storage time and activation method (p <0.0001). RFB values for self-curing method were statistically lower compared to all other activation methods for all storage periods in both cements. The IL curing-method presented significantly lower BFS values compared with DL curing-method in 15-minutes storage time for both materials and in 24 hours just for RU. For both materials, the self-curing method presented significantly lower BFS values in the15 minutes group compared with the 6 moths group. The BFS values were statistically higher in the 15 minutes group compared with the 6 moths group when employing the DL curing-method for both cements. The BFS values were statistically lower in the 6 months group compared to 24 hours group for self-curing and DL curing-methods for RU cement. For VL cement, most methods presented statistically lower BFS values in 6 months compared to 24 hours group. The conventional dual-cure resin cement (VL) presented statistically higher BFS values compared with RU cement for all methods to 24 hours group. Light curing was essential to obtain immediate BFS values for both resin cements tested. Indirect curing method reduced BFS values in 15-minutes storage time for both resin cements and in 24 hours just for RU. Six-months storage reduced BFS values most methods. The conventional dual-cure resin cement (VL) presented higher or similar BFS values compared to self-adhesive cement (RU).Light is a key factor to obtain the RFB within acceptable standards, regardless of the storage period / Mestrado / Materiais Dentarios / Mestra em Materiais Dentários

OBJECTIVES: The purpose of this study was to investigate the influence of saliva contamination and subsequent surface treatments on the shear bond strength of two different resin cements to zirconia. MATERIALS AND METHODS: One hundred sintered zirconia specimens were divided into two groups (n=50), one for each resin cement to be tested. Each group was divided into five sub-groups (n=10) based on the surface treatment the zirconia plates were going to receive; namely control (CL), saliva contaminated (SC), water washed (WW), Ivoclean (IC) and air abrasion (AA). In the control group, no contamination or surface treatment was performed. Specimen surfaces of the rest of the experimental groups were contaminated with saliva, and then submitted to drying with air only (SC); washed with water (WW); treated with Ivoclean cleaning paste (IC); or sandblasted with aluminum oxide particles (Al2O3) (AA). Multilink Automix (MA) and RelyX Ultimate (RU) resin cement cylinders were made and bonded to conditioned zirconia specimens using the Ultradent jig method. All bonded specimens were placed inside glass containers filled with deionized water inside an incubator at 37 °C for 24 h. After 24 h, the shear bond strength of the bonded specimens was tested using an Instron Universal Testing Machine with a crosshead speed of 0.5 mm/minutes. Statistical analysis was performed by ANOVA and data were analyzed with Tukey-Kramer HSD multiple comparison tests at the 0.05 level of significance. RESULTS: Within the limitations of this in vitro study, it was determined that saliva contamination significantly reduced resin bond strengths to zirconia ceramic. Airborne-particle abrasion was the most effective cleaning and surface treatment. It significantly increased the shear bond strength of (MA) (13.73 ± 1.39 MPa) and (RU) (6.34± 0.8 MPa). The IC was effective in removing saliva contamination and enhancing the resin bond strength of (MA) (10.9 ± 1.28 MPa) and (RU) (3.1± 0.16MPa). Water did not remove saliva contamination and did not improve (RU) bond strength to zirconia (1.73 ± 0.25 MPa). There was no significant difference (p>0.05) between the shear bond strengths of (MA), water washing (4.7± 0.64 MPa), and control groups (4.9± 0.27 MPa). CONCLUSIONS: If contamination occurs, a surface treatment is required to guarantee an adequate interaction between the resin cement and the zirconia surface. Airborne-particle abrasion and Ivoclean surface treatments are effective in removing saliva contamination and enhancing the resin bond strength. Washing with water alone did not improve resin bond strength.

EFFECTS OF ETCHING DURATION ON THE SURFACE ROUGHNESS, SURFACE LOSS, FLEXURAL STRENGTH OF E.MAX CAD GLASS CERAMIC AND SHEAR BOND STRENGTH TO A RESIN CEMENT Background: Long-term retention of ceramic restorations is dependent on the bond strength of the luting resin to both the tooth and porcelain substrates. In order to achieve successful bonding, the surface of the porcelain substrate must be modified to increase the surface roughness, and this can be achieved chemically by hydrofluoric (HF) acid etching. However, prolonged HF acid etching has shown to have a weakening effect on the evaluated lithium disilicate glass-ceramics. Therefore, it is essential to quantify the required etching duration of HF acid to minimize the possible deleterious effects on ceramic strength while maximizing the bond strength to tooth structure. Objectives: To evaluate the effects of HF acid etching duration on the surface roughness, surface loss, flexural strength, and shear bond strength of IPS e.max CAD (Ivoclar Vivadent) lithium disilicate-based glass ceramic to a resin cement. Hypothesis: The differences in HF acid etching durations will not have a significant effect on the surface roughness, surface loss, flexural strength, or shear bond strength of IPS e.max CAD to a resin cement. Methods: 168 specimens were prepared from IPS e.max CAD blocks. All specimens were polished and sonically cleaned in distilled water. Specimens were fired in the vacuum pump furnace according to the manufacturer’s instructions. Specimens were then divided into 4 groups, according to etching durations, then further divided into 3 subgroups, according to the properties tested. Group A was not etched (control), Groups B, C and D were etched with 5-percent HF acid (IPS Ceramic Etching gel, Ivoclar Vivadent) for 20 s, 60 s and 90 s respectively. The morphologies of both etched and non-etched surfaces in specimens of subgroup 1 of each etching group (n = 16/group) were observed under scanning electron microscopy (SEM). In addition, non-contact surface profilometry (Proscan 2000) was used to calculate the surface loss and to examine the surface roughness of the etched ceramic surfaces and roughness values (Ra, Rq) were documented for each group. Furthermore, etched specimens of subgroup 2 (n = 16/group) were silanated (Monobond Plus, Ivoclar Vivadent) and cemented with a resin cement (Multilink Automix, Ivoclar Vivadent). The shear bond strength (SBS) was measured using a universal mechanical testing machine. For each etching group, subgroup 3 specimens (n = 10/group) were loaded to failure in a three-point bending test to measure their flexural strength values using a universal mechanical testing machine. Data for surface roughness, surface loss, and flexural strength were analyzed using one-way analysis of variance (ANOVA), to identify the significant effects of different HF acid etching durations. Data for shear bond strength test were analyzed using two-way ANOVA to test the effects of etching duration, storage for 24 hours/thermocycling, and their interaction. All pair-wise comparisons from ANOVA analysis were made using Fisher’s Protected Least Significant Differences to control the overall significance level at 5 percent. Results: Difference in HF etching durations did not have a significant effect on surface roughness values Ra or Rq (p = 0.3408; p = 0.3245) respectively, but had a significant effect on surface loss (p = 0.0006). SBS values were not significantly different between experimental groups (p = 0.4650); however, SBS values after 24-h storage were significantly higher than that found after thermocycling (p = 0.0166) among different etching durations. Finally, different HF etching durations did not have a significant effect on flexural strength values (p = 0.1260). Conclusion: Within the limitations of this study, different HF etching durations did not have a significant effect on surface roughness, flexural strength, or shear bond strength of IPS e.max CAD. However, the different etching durations significantly affected the surface loss of the lithium disilicate glass ceramics.

Indiana University-Purdue University Indianapolis (IUPUI) / New products are frequently developed for bonding brackets. This continuum brings about incessant studies attempting to prove or disprove their value. The need to compare the results of bond failure studies is made difficult if not impossible by the variation of published testing methods. The purpose of this study is to compare the differential effects of thermocycling, as a lab protocol, on three debonding techniques, shear-peel, tension, and torsion when using a traditional orthodontic resin adhesive. A standard orthodontic resin, Transbond™ XT (3M Unitek, Monrovia, CA) was used to bond 102 flattened 0.018-inch stainless steel brackets (3M Unitek) to flattened bovine incisors. Two step acid etching and priming (37 % phosphoric acid gel and Transbond MIP Primer, 3M Unitek) was used to prepare the enamel for bonding. During bonding, the resin thickness was held consistent. The bonding was accomplished under controlled temperature and humidity. Half of the samples were thermocycled prior to debonding. The samples were debonded in shear-peel, tension, and torsion. The data showed no significant differences between thermocycling and nonthermocycling in shear-peel or torsion, but in tension the thermocycling group had a statistically significant higher failure load. Overall, was a trend toward increased bond strength in the thermocycled group. The increase is likely the result of continued polymerization during thermocycling. The statistical difference that is noted in tension is thought to be due to the location of the highest stress being in the center of the resin pad. This would be the location of the least initial polymerization. The use of thermocycling as a lab protocol during bracket failure studies in shear-peel and torsion is not necessary when using traditional orthodontic resin.

O objetivo deste estudo foi avaliar a influência do tipo de sistema de cimentação (condicionamento ácido total ou autoadesivo), do modo de ativação (autoativado ou dual), do terço do conduto radicular (cervical, médio ou apical) e da espessura do filme de cimento sobre a resistência de união de pinos de fibra de vidro cimentados em dentes humanos. Quarenta raízes foram incluídas em resina epóxi, submetidas a tratamento endodôntico e obturadas com guta percha e cimento endodôntico sem eugenol. Decorridos sete dias, os condutos foram preparados a uma profundidade de 10mm com brocas padronizadas do sistema dos pinos de fibra (WhitePost DC #2) e aleatoriamente divididos em 4 grupos, conforme o sistema de cimentação e o modo de ativação: (G1) RelyX ARC/Adper Scotchbond Multi-Purpose Plus (condicionamento ácido total), ativação dual, (G2) RelyX ARC/Adper Scotchbond Multi-Purpose Plus, autoativado, (G3) RelyX U100 (autoadesivo), dual e (G4) RelyX U100, autoativado. Após uma semana, cada raiz foi seccionada em máquina de corte, originando 6 fatias de 1 mm de espessura (n=60). Antes do ensaio de push-out cada fatia foi fotografada em ambas as faces, para determinação do raio dos pinos e da espessura do filme de cimento. Após o ensaio mecânico, novas imagens foram capturadas para determinação do modo de falha. Para automatizar a determinação da espessura de cimento, foi desenvolvida uma macro no software KS 400. Os dados foram estatisticamente analisados com ANOVA 3 fatores (resistência de união) e teste de Kruskall-Wallis (espessura do cimento). Comparações múltiplas foram realizadas com o teste Student-Newman-Keuls. Análise de regressão, modelo linear, foi empregada para verificar a correlação entre espessura do cimento e resistência de união. Todos os testes foram aplicados com &#945; = 0,05. O fator cimento exerceu influência significativa para a resistência de união (p = 0,0402): o RelyX U100 apresentou a maior média. A ativação dual elevou os valores de resistência de união em comparação ao modo quimicamente ativado (p < 0,0001). Houve diferenças significantes entre os grupos, sendo G1 (22,4 4,0 MPa) > G3 (20,4 3,6 MPa) > G4 (17,8 5,2 MPa) > G2 (13,5 4,3 MPa). O terço do conduto não exerceu influência significativa sobre a resistência adesiva (p = 0,4749). As espessuras dos filmes de cimento foram estatisticamente diferentes nos diferentes terços: cervical (102 45 m) > médio (75 29 m) > apical (52 28m). Não foi observada forte correlação entre os valores de espessura e os de resistência ao push-out (r = - 0,2016, p = 0,0033). O tipo de falha predominante foi a mista, exceto para o G2, que apresentou 74% das falhas na interface cimento-pino. Dessa forma, o cimento autoadesivo apresentou melhor desempenho que o convencional, e ambos os sistemas duais, sobretudo o RelyX ARC, apresentaram dependência da fotoativação para atingirem maiores valores de resistência de união. / The aim of this study was to evaluate the influence of adhesive cementation system approach (total-etch or self-adhesive), activation mode (self-cure or dual-cure), canal third (cervical, middle or apical) and cement thickness on push-out bond strength of glass fiber post bonded on human roots. Forty roots were embebed in epoxy resin and endodontically treated (filled with guta percha and non-eugenol endodontic sealer). Following 7 days, the post spaces were prepared with low-speed post drills provided by the manufacturer (WhitePost DC #2, FGM) at a depth of 10 mm and the roots were randomly divided in 4 groups, according to cementation system and activations mode: (G1) RelyX ARC/Adper Scotchbond Multi-Purpose Plus (total-etch), dual-cure (G2) RelyX ARC/Adper Scotchbond Multi-Purpose Plus, self-cure, (G3) RelyX U100 (self-adhesive), dual-cure and (G4) RelyX U100, self-cure. After 7 days, each root was sectioned with water-cooled diamond blade, generating six 1-mm thickness slices (n=60). Before push-out bond strength test, digital images of both sides of the slices were captured with digital camera, in order to measure the post radius and the cement thickness. After mechanical test, new images were captured to evaluate the failure mode. A macro was developed in KS 400 software to speed and standardize the evaluation of cement thickness. Results were analyzed using three-way ANOVA (push-out) and Kruskall-Wallis test (cement thickness). Post-hoc multiple comparisons were performed using the Student-Newman-Keuls test. The correlation between resin cement thickness and bond strength was evaluated with regression analysis, linear model. All tests were performed with significance level set at 0.05. Push-out bond strength was significantly influenced by cement type (p= 0.0402): the RelyX U100 cement presented higher mean value. The dual-activated mode increased the bond strength in comparison to self-activated mode (p < 0.0001). Statically differences were observed between groups: G1 (22.4 4.0 MPa) > G3 (20.4 3.6 MPa) > G4 (17.8 5.2 MPa) > G2 (13.5 4.3 MPa). Bond strength was not affected by post space depth (p = 0,4749). The resin cement thicknesses were significantly different in root thirds: cervical (102 45 m) > middle (75 29 m) > apical (52 28m). No strong correlation between cement thickness and push-out bond strength was observed (r = - 0.2016, p = 0.0033). The main failure mode was mixed, except for G2 (74% adhesive failures at post-cement interface). It was concluded tha the self-adhesive cement showed a better performance than the conventional one, and both dual resin systems, specially the RelyX ARC, presented photo-activation dependence to attain greater adhesive bond strength.

O objetivo deste estudo foi avaliar a influência do tipo de sistema de cimentação (condicionamento ácido total ou autoadesivo), do modo de ativação (autoativado ou dual), do terço do conduto radicular (cervical, médio ou apical) e da espessura do filme de cimento sobre a resistência de união de pinos de fibra de vidro cimentados em dentes humanos. Quarenta raízes foram incluídas em resina epóxi, submetidas a tratamento endodôntico e obturadas com guta percha e cimento endodôntico sem eugenol. Decorridos sete dias, os condutos foram preparados a uma profundidade de 10mm com brocas padronizadas do sistema dos pinos de fibra (WhitePost DC #2) e aleatoriamente divididos em 4 grupos, conforme o sistema de cimentação e o modo de ativação: (G1) RelyX ARC/Adper Scotchbond Multi-Purpose Plus (condicionamento ácido total), ativação dual, (G2) RelyX ARC/Adper Scotchbond Multi-Purpose Plus, autoativado, (G3) RelyX U100 (autoadesivo), dual e (G4) RelyX U100, autoativado. Após uma semana, cada raiz foi seccionada em máquina de corte, originando 6 fatias de 1 mm de espessura (n=60). Antes do ensaio de push-out cada fatia foi fotografada em ambas as faces, para determinação do raio dos pinos e da espessura do filme de cimento. Após o ensaio mecânico, novas imagens foram capturadas para determinação do modo de falha. Para automatizar a determinação da espessura de cimento, foi desenvolvida uma macro no software KS 400. Os dados foram estatisticamente analisados com ANOVA 3 fatores (resistência de união) e teste de Kruskall-Wallis (espessura do cimento). Comparações múltiplas foram realizadas com o teste Student-Newman-Keuls. Análise de regressão, modelo linear, foi empregada para verificar a correlação entre espessura do cimento e resistência de união. Todos os testes foram aplicados com &#945; = 0,05. O fator cimento exerceu influência significativa para a resistência de união (p = 0,0402): o RelyX U100 apresentou a maior média. A ativação dual elevou os valores de resistência de união em comparação ao modo quimicamente ativado (p < 0,0001). Houve diferenças significantes entre os grupos, sendo G1 (22,4 4,0 MPa) > G3 (20,4 3,6 MPa) > G4 (17,8 5,2 MPa) > G2 (13,5 4,3 MPa). O terço do conduto não exerceu influência significativa sobre a resistência adesiva (p = 0,4749). As espessuras dos filmes de cimento foram estatisticamente diferentes nos diferentes terços: cervical (102 45 m) > médio (75 29 m) > apical (52 28m). Não foi observada forte correlação entre os valores de espessura e os de resistência ao push-out (r = - 0,2016, p = 0,0033). O tipo de falha predominante foi a mista, exceto para o G2, que apresentou 74% das falhas na interface cimento-pino. Dessa forma, o cimento autoadesivo apresentou melhor desempenho que o convencional, e ambos os sistemas duais, sobretudo o RelyX ARC, apresentaram dependência da fotoativação para atingirem maiores valores de resistência de união. / The aim of this study was to evaluate the influence of adhesive cementation system approach (total-etch or self-adhesive), activation mode (self-cure or dual-cure), canal third (cervical, middle or apical) and cement thickness on push-out bond strength of glass fiber post bonded on human roots. Forty roots were embebed in epoxy resin and endodontically treated (filled with guta percha and non-eugenol endodontic sealer). Following 7 days, the post spaces were prepared with low-speed post drills provided by the manufacturer (WhitePost DC #2, FGM) at a depth of 10 mm and the roots were randomly divided in 4 groups, according to cementation system and activations mode: (G1) RelyX ARC/Adper Scotchbond Multi-Purpose Plus (total-etch), dual-cure (G2) RelyX ARC/Adper Scotchbond Multi-Purpose Plus, self-cure, (G3) RelyX U100 (self-adhesive), dual-cure and (G4) RelyX U100, self-cure. After 7 days, each root was sectioned with water-cooled diamond blade, generating six 1-mm thickness slices (n=60). Before push-out bond strength test, digital images of both sides of the slices were captured with digital camera, in order to measure the post radius and the cement thickness. After mechanical test, new images were captured to evaluate the failure mode. A macro was developed in KS 400 software to speed and standardize the evaluation of cement thickness. Results were analyzed using three-way ANOVA (push-out) and Kruskall-Wallis test (cement thickness). Post-hoc multiple comparisons were performed using the Student-Newman-Keuls test. The correlation between resin cement thickness and bond strength was evaluated with regression analysis, linear model. All tests were performed with significance level set at 0.05. Push-out bond strength was significantly influenced by cement type (p= 0.0402): the RelyX U100 cement presented higher mean value. The dual-activated mode increased the bond strength in comparison to self-activated mode (p < 0.0001). Statically differences were observed between groups: G1 (22.4 4.0 MPa) > G3 (20.4 3.6 MPa) > G4 (17.8 5.2 MPa) > G2 (13.5 4.3 MPa). Bond strength was not affected by post space depth (p = 0,4749). The resin cement thicknesses were significantly different in root thirds: cervical (102 45 m) > middle (75 29 m) > apical (52 28m). No strong correlation between cement thickness and push-out bond strength was observed (r = - 0.2016, p = 0.0033). The main failure mode was mixed, except for G2 (74% adhesive failures at post-cement interface). It was concluded tha the self-adhesive cement showed a better performance than the conventional one, and both dual resin systems, specially the RelyX ARC, presented photo-activation dependence to attain greater adhesive bond strength.