Evaluation of dentin microroughness and composite bond strength after multiple uses of diamond burs / Evaluación de la micro rugosidad dentinaria y la resistencia adhesiva de composites tras múltiples usos de fresas de diamante

Abstract Using a bur multiple times to prepare dental structure may produce a smoother final surface on dentin than a new one. This superficial roughness may affect adhesion with resin-based materials by modifying the substrates' characteristics. The aim of this study was to evaluate the effect of multiple uses of diamond burs on dentin's superficial microroughness and bond strength with resin composite when using a self-etch adhesive. Diamond dental burs were used to simulate a preparation (dentin flat surface) on extracted third molars. Samples were distributed into groups according to burs' number of previous uses as follows: 0, 1, 5 and 10. Scanning electron microscopy images at 70x, 350x, and 1000x were used to illustrate burs' deformation. Each specimen's dentin microroughness was measured three times to compare between experimental groups and the micro-shear bond strength test (n=15) was performed for the 0 and 10 uses groups using a universal adhesive in a self- etching mode. Diamond crystals wear and dislodgements were evident among groups where the burs were used more times. As the number of uses increased the mean microroughness of the dentin surface decreased with significant differences between the 0 and 10 uses groups. No statistical differences between experimental groups resulted from bond strength tests. When using a universal adhesive in a self-etching mode, the number of previous uses of a diamond bur seems to have no significant effect on dentin/resin composite bond strength.

Resumen El uso de una fresa múltiples veces para preparar la estructura dental puede producir una superficie final más lisa en la dentina que una fresa nueva. Esta rugosidad superficial modifica las características del sustrato y puede afectar la adhesión con materiales resinosos. El objetivo de este estudio fue evaluar el efecto de los múltiples usos de las fresas de diamante sobre la micro rugosidad superficial de la dentina y la resistencia adhesiva con la resina compuesta cuando se utiliza un adhesivo de autograbado. Se utilizaron fresas dentales de diamante para simular una preparación (superficie plana de la dentina) en terceros molares extraídos. Las muestras se distribuyeron en grupos según el número de usos previos de las fresas de la siguiente manera: 0, 1, 5 y 10. Se utilizaron imágenes de microscopía electrónica de barrido a ×70, ×350 y ×1000 para ilustrar la deformación de las fresas. Se midió la micro rugosidad de la dentina de cada espécimen tres veces para comparar entre los grupos experimentales y se realizó la prueba de resistencia a la adhesión por micro cizallamiento (n=15) para los grupos de 0 y 10 usos utilizando un adhesivo universal en modo de autograbado. El desgaste de los cristales de diamante y los desprendimientos fueron evidentes entre los grupos en los que las fresas se utilizaron más veces. A medida que aumentaba el número de usos, la micro rugosidad media de la superficie de la dentina disminuyó, con diferencias significativas entre los grupos de 0 y 10 usos. En las pruebas de resistencia adhesiva no se observaron diferencias estadísticas entre los grupos experimentales. Cuando se utiliza un adhesivo universal en modo de autograbado, el número de usos previos de una fresa de diamante no parece tener un efecto significativo en la resistencia de la unión dentina/resina del composite.

Effect of silver diamine fluoride, potassium iodide, and glutathione on micro-shear bond strength of glass ionomer cement to caries affected dentine

Background: Silver diamine fluoride (SDF, 38%) is an efficient topical fluoride used to arrest dental caries though it causes black staining of both teeth and restoration. The application of potassium iodide (KI) after SDF reduces the stain, but the color change is only temporary. An alternative method suggested is by mixing glutathione (GSH) with SDF, which preserves the silver ions of SDF within the solution. Hence, the purpose of this in vitro study was to evaluate the microshear bond strength (?SBS) of glass ionomer cement (GIC) to caries affected dentin (CAD) pretreated with SDF/KI/GSH. Materials and Methods: Thirty dentine slices of 2 mm thickness from human permanent upper premolars were demineralized using pH cycling method to mimic CAD. They were allocated to three groups of 10 each and treated with SDF, SDF-KI (SDF followed by KI), SDF + GSH (SDF mixed with GSH), respectively. Specimens were bonded with GICs. The ?SBS was assessed using a universal testing machine and the data obtained were analyzed using one-way ANOVA and Tukey's post hoc test. Results: The ?SBS (mean ± standard deviation) values for groups SDF, SDF-KI, and SDF + GSH were 4.81 ± 2.026, 5.78 ± 1.809, 8.18 ± 2.828 megapascal respectively. Group 3 showed significantly better bond strength compared to groups 1 and 2. In group 2, the addition of KI showed better bond strength when compared to group 1, but the difference was not statistically significant. Conclusion: Pretreatment of teeth with GSH along with SDF application showed significantly better bond strength of GIC to CAD compared to SDF and SDF-KI.

Evaluation of enamel roughness after the removal of brackets bonded with different materials: In vivo study

Abstract The aims of this in vivo study were to evaluate the effect of bonding with resin-modified glass ionomer cement (RMGIC) and to assess enamel surface roughness before and after the removal of brackets bonded with composite or RMGIC from the maxillary central incisors. Fifteen orthodontic patients were selected for the study. For each patient, the teeth were rinsed and dried, and brackets were bonded with composite (Transbond XT) and RMGIC (Vitremer Core Buildup/Restorative). At the conclusion of orthodontic treatment, their brackets were removed. Dental replicas were made of epoxy resin in initial conditions (before bonded) and after polishing with an aluminum oxide disc system. Adhesive remnant index (ARI) and surface roughness was measured on the dental replicas and data were evaluated statistically by Mann-Whitney and paired t-test, respectively. No bracket debonding occurred during patients' treatment periods. It was verified that the ARI values of the two maxillary central incisors were similar (p = 0.665). For both bonding materials, the ARI value of 3 was predominant. After polishing, surface roughness was similar in the composite and RMGIC groups (0.245 μm and 0.248 μm, respectively; p = 0.07). In both groups, enamel surface roughness values were significantly lower after polishing compared with the initial condition (p < 0.001). RMGIC promoted efficiency in cementing brackets without fail during treatment; the choice of composite or RMGIC materials was not a factor that influenced the roughness of the enamel surface, however, polishing led to smoother surfaces than those found at the beginning of the treatment.

Resumo Os objetivos deste estudo in vivo foram avaliar o efeito da colagem com cimento de ionômero de vidro modificado por resina (CIVMR) e a rugosidade da superfície do esmalte antes e após a remoção dos braquetes colados com compósito ou CIVMR em incisivos centrais superiores. Quinze pacientes ortodônticos foram selecionados para o estudo. Para cada paciente, os dentes foram lavados e secos, e os braquetes colados com compósito (Transbond XT) e CIVMR (Vitremer Core Buildup / Restorative). Ao término do tratamento ortodôntico, os braquetes foram removidos. As réplicas dentais foram confeccionadas em resina epóxica nas condições iniciais (antes da colagem) e após o polimento com sistema de discos de óxido de alumínio. O índice de remanescente adesivo (IRA) e a rugosidade da superfície foram mensurados nas réplicas dentais e os dados foram avaliados estatisticamente por Mann-Whitney e teste t pareado, respectivamente. Não ocorreu descolagem de braquetes durante os períodos de tratamento dos pacientes. Verificou-se que os valores do IRA dos dois incisivos centrais superiores foram semelhantes (p = 0,665). Para ambos os materiais de colagem, o valor de IRA predominante foi 3. Após o polimento, a rugosidade da superfície do esmalte foi semelhante nos grupos compósito (0,245 μm) e CIVMR (0,248 μm) (p = 0,07). Em ambos os grupos, os valores de rugosidade da superfície do esmalte foram significativamente menores após o polimento em comparação com a condição inicial (p <0,001). CIVMR promoveu eficiência na colagem de braquetes sem falhas durante o tratamento; a escolha dos materiais compósito ou CIVMR não foi um fator que influenciou na rugosidade da superfície do esmalte, porém, o polimento levou a superfícies mais lisas do que as encontradas no início do tratamento.

Bonding performance of self-etch adhesives to enamel bleached with different peroxide concentrations

Abstract The aim of this study was to evaluate the micro-shear bond strength (µSBS) of one and two steps self-etch adhesive systems after enamel bleaching with photo-activated bleaching systems of different hydrogen peroxide (HP) concentration. Occlusal enamel of forty intact human molars were flattened and assigned into four groups. GI Unbleached, GII, GIII, and GIV were bleached with Pyrenees (3.5% HP), GC TiON (20% HP), and Hi-Lite (35% HP) respectively. Enamel treatment with one and two steps self-etch adhesives (Clearfil S3 Bond- S3, and Clearfil SE Bond-SE) then micro-tubes were fixed on enamel and filled with AP-X composite (n=5). Bond was tested with the universal testing machine. Data were analyzed using two-way ANOVA and Tukey's tests at 5 % level of significance. The µSBS was significantly different between adhesives (F=154.46; p<0.05) and bleaching systems (F=77.33; p<0.05) with significant interaction. Specimens bonded with S3 shows a significantly lower μSBS than those bonded with SE (p<0.05) in all groups. For both adhesives the bleached groups demonstrate lower µSBS than unbleached except specimens bleached with Pyrenees and bonded with SE (p>0.05). A significant difference was observed between groups of the bleaching systems (p<0.05). Different peroxide concentrations photo-activated bleaching systems adversely affect μSBS of one and two steps self-etch adhesives. Low concentration system (Pyrenees) does not influence the bond strength of two steps adhesive.

Resumo O objetivo deste estudo foi avaliar a resistência ao cisalhamento (µSBS) de sistemas auto-adesivos de um e dois passos após clareamento do esmalte com sistemas de clareamento foto-ativados de diferentes concentrações de peróxido de hidrogênio (HP). O esmalte oclusal de quarenta molares humanos intactos foi aplainado e atribuído em quatro grupos. GI Unbleached, GII, GIII, e GIV foram branqueados com Pyrenees (3,5% HP), GC TiON (20% HP), e Hi-Lite (35% HP) respectivamente. Tratamento de esmalte com adesivos de um e dois passos auto-adesivos (Clearfil S3 Bond- S3, e Clearfil SE Bond-SE), depois os microtubos foram fixados no esmalte e preenchidos com composto AP-X (n=5). A resistência ao cisalhamento foi testada com a máquina universal de testes. Os dados foram analisados usando os testes de ANOVA e Tukey de duas vias a um nível de 5% de significância. O µSBS foi significativamente diferente entre adesivos (F=154,46; p<0,05) e sistemas de clareadores (F=77,33; p<0,05) com interação significativa. Os espécimes colados com S3 mostram um μSBS significativamente inferior aos colados com SE (p<0,05) em todos os grupos. Para ambos os adesivos, os grupos clareados demonstram µSBS inferiores aos não clareados exceto os espécimes clareados com Pyrenees e colados com SE (p>0,05). Foi observada uma diferença significativa entre os grupos dos sistemas de clareamento (p<0,05). Diferentes concentrações de peróxidos foto-ativados nos sistemas de clareamento afetam negativamente μSBS dos adesivos de uma e duas etapas de auto-colagem. O sistema de baixa concentração (Pyrenees) não influenciou a resistência ao cisalhamento do adesivo de duas etapas.

Effect of Protein-Based Treatment on Chemical Composition, Hardness and Bond Strength of Remineralized Enamel

Abstract This study evaluated the chemical composition and microhardness of human enamel treated with an Enamel Matrix Derivative (EMD) solution, and the bond strength between composite resin and this enamel. Thirty human enamel samples were randomly divided into three groups: Untouched Enamel (UE), Demineralized Enamel (DE) and Demineralized Enamel Treated with EMD (ET). DE and ET groups were subjected to acid challenge and ET treated with EMD (EMD was directly applied over conditioned enamel and left for 15 min). Samples from each group (n=4) had chemical composition assessed through to attenuated total reflectance Fourier transform infrared (ATR-FTIR). Knoop microhardness of enamel samples from each group (n=10) was measured. For the microshear bond strength, the samples were etched for 30 s, and the adhesive was applied and cured for 10 s. Two matrixes were placed on the samples, filled with Filtek Z350 XT composite and cured for 20 s, each. The matrix was removed, and the microshear bond strength of each group (n=10) was tested. Data were subjected to Kruskal-Wallis test (for microhardness), to analysis of variance and to Tukey's test (for microshear bond strength); (α=0.05). FTIR results have shown phosphate (hydroxyapatite indicator) in 900-1200 cm-1 bands in the UE and ET groups, which were different from the DE group. Microhardness and microshear analyses recorded higher statistical values for the UE and ET groups than for DE. EMD application to demineralized enamel seems to have remineralized the enamel; thus, the microhardness and bond strength was similar between UE and ET groups.

Resumo Este estudo avaliou a composição química e microdureza do esmalte humano tratado com solução de Derivados da Matriz do Esmalte (EMD) e a resistência de união entre compósito e este esmalte. Trinta amostras de esmalte humano foram aleatoriamente divididas em três grupos: Esmalte Intocado (UE), Esmalte Desmineralizado (DE) e Esmalte Desmineralizado Tratado com EMD (ET). Os grupos DE e ET foram submetidos a desafio ácido e ET tratado com EMD (O EMD foi aplicado diretamente sobre esmalte condicionado e deixado por 15 minutos). Amostras de cada grupo (n = 4) tiveram composição química avaliada através de espectroscopia no infravermelho por transformada de Fourier com reflectância total atenuada (FTIR-ATR). A microdureza Knoop das amostras de esmalte de cada grupo (n=10) foi mensurada. Para a resistência ao microcisalhamento, as amostras foram condicionadas por 30 s, o adesivo aplicado e foto-ativado por 10 s. Duas matrizes plásticas (1 mm de comprimento) foram posicionadas sobre as amostras, preenchidas com compósito Filtek Z350 XT e foto-atiavadas por 20 s cada. As matrizes foram removidas e a resistência ao microcisalhamento de cada grupo (n=10) foi testada. Os dados foram submetidos ao teste de Kruskal-Wallis (para análise da microdureza), à análise de variância e ao teste de Tukey (para análise da resistência ao microcisalhamento); (α=0.05). Os resultados do FT-IR mostraram fosfato (indicador de hidroxiapatita) na banda entre 900-1200 cm-1 nos grupos UE e ET, diferentemente do grupo DE. Análises de microdureza e microcisalhamento demonstraram resultados estatisticamente superiores para os grupos UE e ET quando comparados ao DE. A aplicação de EMD ao esmalte desmineralizado parece ter remineralizado o esmalte; assim, a microdureza e a resistência de união foram semelhantes entre os grupos UE e ET.

Micro-shear bond strength of bioactive cement to translucent zirconia after thermocycyling: a comparative in-vitro study / Resistência de união ao microcisalhamento do cimento bioativo à zircônia translúcida após termociclagem: estudo comparativo in vitro

Objective: the purpose of the study was to evaluate the micro-shear bond strength of different cements to translucent zirconia before and after thermocycling aging. Material and methods: Twelve translucent zirconia ceramic discs were used in the study. Specimens were sandblasted using 50 µm aluminum oxide (Al2 O3 ) particles. The specimens were divided into three groups (n = 4) according to the cement type: Panavia resin cement (control group), resin modified glass ionomer (RMGI), and Activa bioactive cement. Each group was further sub-divided into two equal subgroups (n = 2) according to whether the specimens were subjected to thermocycling or not. Thermocycling was performed in distilled water at 5000 cycles between 5 o C - 55 o C. The micro-shear bond strength test (µSBS) was measured using universal testing machine. Kruskal-Wallis test was used to compare between the three cements. Dunn's test was used for pair-wise comparisons when Kruskal-Wallis test is significant. Mann-Whitney U test was used to compare between micro-shear bond strength before and after thermocycling P ≤ 0.05. Results: In non-aged subgroups, there was no significant difference between Panavia and Activa; both showed significantly the highest mean µSBS values (22.9 MPa, 31.3 MPa respectively). While, RMGI showed the lowest µSBS values (4.7 MPa). In thermocycled subgroups, Panavia showed significantly the highest mean µSBS values (32.2 MPa). There was no significant difference between RMGI and Activa; both showed the lowest significant mean µSBS values (3.2 MPa and 8.7 MPa respectively). Conclusions: RMGI and Activa couldn't be considered long-term reliable materials for cementing zirconia. However, Panavia provided the most durable bond to zirconia. (AU)

Objetivo: O objetivo do estudo foi avaliar a resistência de união ao microcisalhamento de diferentes cimentos à zircônia translúcida antes e após o envelhecimento da termociclagem. Material e métodos: Doze discos de zircônia translúcidos foram utilizados no estudo. As amostras foram jateadas com partículas de óxido de alumínio de 50 µm (Al2 O3 ). Os espécimes foram divididos em três grupos (n = 4), de acordo com o tipo de cimento: cimento resinado Panavia (grupo controle), ionômero de vidro modificado por resina (RMGI) e cimento bioativo Activa. Cada grupo foi subdividido em dois subgrupos iguais (n = 2), dependendo se as amostras foram submetidas ou não a termociclagem. A termociclagem foi realizada em água destilada a 5000 ciclos entre 5°C - 55°C. O teste de resistência de união por microcisalhamento (µSBS) foi medido usando uma máquina de teste universal. O teste de Kruskal-Wallis foi utilizado para comparar os três cimentos. O teste de Dunn foi usado para comparações entre pares quando o teste de Kruskal-Wallis foi significativo. O teste U de Mann-Whitney foi utilizado para comparar a resistência de união ao microcisalhamento antes e após a termociclagem (P ≤ 0,05). Resultados: Nos subgrupos sem envelhecimento por termociclagem, não houve diferença significativa entre Panavia e Activa; ambos mostraram significativamente os maiores valores médios de µSBS (22,9 MPa, 31,3 MPa, respectivamente). Por sua vez, o RMGI apresentou os menores valores de µSBS (4,7 MPa). Nos subgrupos termociclados, Panavia mostrou significativamente os maiores valores médios de µSBS (32,2 MPa). Não houve diferença significativa entre RMGI e Activa; ambos apresentaram os menores valores médios significativos de µSBS (3,2 MPa e 8,7 MPa, respectivamente). Conclusões: RMGI e Activa não puderam ser considerados materiais confiáveis para cimentação à zircônia a longo prazo. No entanto, a Panavia apresentou a ligação mais durável à zircônia. (AU)

Bond strength assessment of a universal adhesive system in etch-and-rinse and self-etch modes / Avaliação da resistência de união de um sistema adesivo universal no modo convencional e autocondicionante

Abstract Introduction Modern dentistry is reflected in the insertion of new materials with different adhesion forms in dental structures, such as the Universal adhesive system. Objective To evaluate the bond strength of the universal dentin adhesive system, in the form of self-etching and conventional application, compared with a simplified conventional adhesive system, in two distinct periods: 1 week and 6 months. Material and method 48 bovine incisors separated into 6 groups, stored for 7 days, were selected. Worn out the buccal enamel until dentin exposure. Adper Single Bond 2 (3M Espe) or SingleBond Universal (3M Espe) adhesives were applied, and catheters filled with Opallis Flow (FGM) composite were placed. After photoactivation, the catheters were removed and the specimens (n ​​= 48), stored in distilled water at 37 °C for one week and six months, were exposed. The specimens were fixed to a universal testing machine (EMIC DL 2000) with a speed of 0.5 mm / min. Bond strength (BS) was calculated in MPa, and data were statistically analyzed by Anova and Tukey test at 5% significance level. Result For Adper Single bond, the BS was equivalent in the times tested; for Universal conventional and self-conditioning time influenced the BS, with a decrease in the results. At 1 week, all stickers were different from each other, with higher BS for Universal conventional mode, followed by universal self-etching mode and then Adper Single bond. Conclusion The best results were achieved with universal adhesive in conventional mode for both tested times.

Resumo Introdução A odontologia moderna é refletida na inserção de novos materiais com diferentes formas de adesão nas estruturas dentárias, como o sistema adesivo Universal. Objetivo Avaliar a resistência adesiva do sistema adesivo universal em dentina, na forma de aplicação auto condicionante e convencional, comparando com um sistema adesivo convencional simplificado, em dois períodos distintos: 1 semana e 6 meses. Material e método Foram selecionados 48 incisivos bovinos separados em 6 grupos, armazenados por 7 dias. Desgastado o esmalte vestibular, até exposição da dentina. Aplicaram-se os adesivos Adper Single Bond 2 (3M Espe) ou SingleBond Universal (3M Espe), e sobre este, posicionados cateteres preenchidos com o compósito Opallis Flow (FGM). Após fotoativação, removeram-se os cateteres e expuseram-se os corpos de prova (n=48), armazenados em água destilada a 37 °C por uma semana e seis meses. Os corpos de prova foram fixados uma máquina universal de ensaios (EMIC DL 2000), com velocidade de 0,5 mm/min. A resistência de união (RU) foi calculada em MPa, e os dados foram analisados estatisticamente pela Anova e pelo teste de Tukey ao nível de 5% de significância. Resultado Para Adper Single bond, a RU foi equivalente nos tempos testados; para Universal modo convencional e autocondicionante o tempo influenciou na RU, havendo um decréscimo nos resultados. Em 1 semana, todos os adesivos foram diferentes entre si, com maior RU para Universal modo convencional, seguido por universal modo autocondicionante e então pelo Adper Single bond. Conclusão O melhor desempenho foi do adesivo universal na forma convencional nos dois tempos testados.

Influence of silver nanoparticles on resin-dentin bond strength durability in a self-etch and an etch-and-rinse adhesive system

OBJECTIVES: This study evaluated the effect of dentin pretreatment with silver nanoparticles (SNPs) and chlorhexidine (CHX) on the microshear bond strength (µSBS) durability of different adhesives to dentin. MATERIALS AND METHODS: Occlusal surfaces of 120 human molars were ground to expose flat dentin surfaces. The specimens were randomly assigned to six groups (n = 20). Three groups (A, B, and C) were bonded with Adper Single Bond 2 (SB) and the other groups (D, E, and F) were bonded with Clearfil SE Bond (SEB). Dentin was pretreated with CHX in groups B and E, and with SNPs in groups C and F. The specimens were restored with Z250 composite. Half of the bonded surfaces in each group underwent µSBS testing after 24 hours and the other half was tested after 6 months of water storage. RESULTS: SNP application was associated with a higher µSBS than was observed in the CHX and control groups for SEB after 24 hours (p < 0.05). A significantly lower µSBS was observed when no dentin pretreatment was applied compared to dentin pretreatment with CHX and SNPs for SB after 24 hours (p < 0.05). The µSBS values of the 6-month specimens were significantly lower than those obtained from the 24-hour specimens for all groups (p < 0.05). This decrease was much more pronounced when both adhesives were used without any dentin pretreatment (p < 0.05). CONCLUSIONS: SNPs and CHX reduced the degradation of resin-dentin bonds over a 6-month period for both adhesive systems.

Adhesion to a lithium disilicate glass ceramic etched with hydrofluoric acid at distinct concentrations

Abstract This study evaluated the effect of different hydrofluoric acid (HF) concentrations on the bond strength between a lithium disilicate-based glass ceramic and a resin cement. Eighty ceramic-blocks (12×7×2 mm) of IPS e.Max CAD (Ivoclar Vivadent) were produced and randomly assigned to 8 groups, considering 2 study factors: HF concentration in 4 levels, i.e., 1% (HF1), 3% (HF3), 5% (HF5), and 10% (HF10), and storage in 2 levels, i.e., baseline (tests were performed 24 h after cementation), and aged (storage for 150 days + 12,000 thermal-cycles at 5°C and 55°C). Acid etching (20 s) was performed, followed by washing, drying, and silanization. Four resin cement cylinders (ϕ= 0.96 mm) were built-up from starch matrices on each ceramic sample (n= 40). Additional ceramic samples were etched and analyzed for contact angle, micro-morphology, and roughness. In baseline condition (without aging), the HF3, HF5, and HF10 groups showed similar bond strength values (13.9 - 15.9 MPa), and HF1 (11.2 MPa) presented lower values than HF5, being that statistically different (p= 0.012). After aging, all the mean bond strengths statistically decreased, being that HF3, HF5, and HF10 (7.8 - 11 MPa) were similar and higher than HF1 (1.8 MPa) (p= 0.0001). For contact angle, HF3, HF5, and HF10 presented similar values (7.8 - 10.4°), lower than HF1 and CTRL groups. HF5 and HF10 presented rougher surfaces than other conditions. For better bond strength results, the tested ceramic may be etched by HF acid in concentrations of 3%, 5%, and 10%.

Resumo Este estudo avaliou o efeito de diferentes concentrações de ácido fluorídrico (HF) na resistência de união entre uma cerâmica vítrea à base de dissilicato de lítio e um cimento resinoso. Oitenta blocos cerâmicos (12×7×2 mm) de IPS e.Max CAD (Ivoclar Vivadent) foram produzidos e distribuídos aleatoriamente em 8 grupos, considerando 2 fatores de estudo: concentração de HF em 4 níveis, isto é, 1% (HF1), 3% (HF3), 5% (HF5), e 10% (HF10), e armazenamento em 2 níveis, isto é, condição inicial (testes foram realizados 24 h após a cimentação), e envelhecidos (150 dias de armazenamento + 12.000 ciclos térmicos a 5°C e 55°C). Condicionamento ácido (20 s) foi realizado, seguido por lavagem, secagem e silanização. Quatro cilindros de cimento resinoso (ϕ= 0.96 mm) foram construídos a partir de matrizes de amido em cada amostra cerâmica (n= 40). Amostras cerâmicas adicionais foram condicionadas e analisadas quanto ao ângulo de contato, micro-morfologia e rugosidade. Na condição inicial (sem envelhecimento), os grupos HF3, HF5, e HF10 mostraram valores de resistência de união similares (13.9 - 15.9 MPa), e HF1 apresentou valores menores que HF5, sendo estatisticamente diferente (p= 0.012). Após o envelhecimento, todas as médias de resistência de união diminuíram estatisticamente, sendo que HF3, HF5 e HF10 foram similares e maiores que HF1 (p= 0.0001). Para o ângulo de contato, HF3, HF5 e HF10 apresentaram valores similares (7.8 - 10.4°), menores que os grupos HF1 e CTRL. HF5 e HF10 apresentaram superfícies mais rugosas que as outras condições. Para melhores resultados de resistência de união, a cerâmica testada pode ser condicionada com ácido fluorídrico nas concentrações de 3%, 5% e 10%.

Eficácia do uso de plasma em pressão atmosférica na adesão de cerâmicas zircônia / Efficacy of the use of plasma at atmospheric pressure in zirconia adhesion

Um dos maiores desafios atuais da ciência dos materiais dentários é a obtenção de união efetiva e durável às cerâmicas de alto conteúdo cristalino. O objetivo do presente estudo foi avaliar a resistência de união, energia de superfície e tipos de fratura de dois sistemas cerâmicos após diferentes formas de tratamento de superfície associada à aplicação do plasma em pressão atmosférica. Para o estudo foram obtidas quarenta placas de zircônia (12 mm x 5 mm x 1,5 mm) de dois tipos de cerâmicas zircônia (E.max ZirCad e Calypso), polidas e limpas por ultrassom durante 5 minutos. Divididas aleatoriamente em 2 grupos de acordo com o sistema cerâmico e 4 subgrupos (n=5) de acordo com o tratamento de superfície, (I) controle (primer), (II) jateamento com partículas micrométricas de alumina (Al2O3) + primer, (III) jateamento com partículas micrométricas de alumina (Al2O3) + plasma + primer, (IV) plasma + primer. Foram confeccionados cento e vinte cilindros de resina composta (Z100), utilizando matrizes cilíndricas (1,0 mm x 3,0 mm) cimentadas com cimento resinoso, Multilink N, sobre as placas de zircônia. Os espécimes foram armazenados em água destilada durante 24 horas a 37° C, depois testados para microcisalhamento em máquina de teste Shimadzu EZ a 1,0 mm/min. Os dados obtidos foram submetidos à análise estatística para comparação entre os grupos E.max e Calypso em relação à resistência à união (força/área ­ MPa), ângulo de contato e os tipos de fratura. Os dados foram analisados pelos testes ANOVA One-Way e Kruskal-Wallis para resistência de união (p=0,003) e (p=0,005) e ângulo de contato (p<0,001) e (p<0,001). Não houve diferença significativa para os dados de fratura (p=0,145), pelo teste quiquadrado, com predomínio de fraturas mistas. Os valores de resistência de união das cerâmicas Y-TZP apresentaram maiores valores quando o plasma foi associado ao jateamento com óxido de alumínio e/ou primer e a aplicação somente do plasma não superou os valores alcançados pelas outras formas de tratamento da superfície. Essa associação resultou em menores valores dos ângulos de contato. Houve maior frequência de fraturas mistas quando realizado somente o tratamento com óxido de alumínio e quando em associação com o plasma.(AU)

One of the major challenges today in the science of dental materials is the achievement of effective and durable bonding to ceramics with high crystalline content. The objective of the present study was to evaluate the efficacy of plasma at atmospheric pressure in the adhesion of ceramic zirconia through the bond strength, surface energy and type of fracture of two ceramic systems after different forms of surface treatment associated with the application of plasma at atmospheric pressure. For the study forty zirconia plates (12 mm x 5 mm x 1.5 mm) were obtained from two zirconia ceramics (E.max ZirCad and Calypso), polished and cleaned by ultrasound for 5 minutes. Randomly divided into 2 groups according to the ceramic system and 4 subgroups (n = 5) according to the surface treatment, control (primer), primer + blasting with micrometric alumina (Al2O3) particles, primer + blasting with micrometric particles of alumina (Al2O3) + plasma, primer + plasma. One hundred and twenty cylinders of composite resin (Z-100) were made using cylindrical matrices (1.0 mm x 3.0 mm) cemented on the zirconia plates. The specimens were stored in distilled water for 24 hours at 37°C, then tested for microshear on a Shimadzu EZ test machine at 0.5 mm / min. The obtained data were submitted to statistical analysis for comparison between the E.max and Calypso groups in relation to the bond strength (strength / area - Mpa), contact angle and fracture types. The data were analyzed by ANOVA One-Way and Kruskal-Wallis tests for bond strength (p=0.003) and (p=0.005) and contact angle (p<0.001) and (p<0.001). There was no significant difference for the fracture data (p = 0.145), by the chi-square test, with a predominance of mixed fractures. The bond strength values of the Y-TZP ceramics showed higher values when the plasma was associated with blasting with aluminum oxide and / or primer and the application of only the plasma did not exceed the values reached by the other forms of surface treatment. This association resulted in lower values of contact angles. It is a higher frequency of mixed fractures when only aluminum oxide treatment is performed and when it is associated with plasma.(AU)

Reparo em resina composta: qual o protocol mais efetivo? / Composite resin repairs: what is the most effective protocol?

Objetivo: Avaliar o efeito da associação de tratamentos de superfície e agentes de união na resistência adesiva de reparos em resinas compostas. Materiais e Métodos: Cento e vinte espécimes de resina composta microhíbrida (Filtek Z250) envelhecidas em água destilada a 37 ºC por 6 meses foram submetidas a diferentes tratamentos de superfície antes do procedimento de reparo. Dez espécimes foram divididos aleatoriamente em 12 grupos: não tratados / sem agente de união (controle negativo); jateamento/sem agente de união; silano /sem agente de união; não tratado / adesivo de condicionamento ácido total; não tratado/ adesivo autocondicionante 1 passo; Não-tratado/adesivo autocondicionante 2 passos; Jateamento / adesivo de condicionamento ácido total; Jateamento / adesivo autocondicionante 1 passo; Jateamento / adesivo autocondicionante 2 passos; silano / adesivo de condicionamento ácido total; silano / adesivo autocondicionante 1 passo; silano / adesivo autocondicionante 2 passos. A resistência adesiva do procedimento de reparo com resina composta foi mensurada pelo teste de microcisalhamento. Resultados: ANOVA a 2 fatores e o teste de Tukey (α = 0,05) demonstraram diferença estatística significante entre os tratamentos de superfície e os sistemas adesivos. Conclusão: Os tratamentos de superfície foram capazes de aumentar a eficácia do reparo em resina composta apesar do agente de união utilizado em superfícies não tratadas. Os agentes de união autocondicionantes foram mais eficazes nos procedimentos de reparo quando não foi realizado tratamento de superfície. (AU)

Objective: The objective of this study was to evaluate the effect of combination of surface treatments and bonding agents on bond strength of repairs on aged composite resin. Materials and Methods: One hundred twenty microhybrid composite samples (Filtek Z250) aged in distilled at 37 ºC water for six months were submitted to different surface treatment prior to resin repairs. Ten specimens were randomly divided into 12 groups: non-treated/no bonding agent (negative control), sandblasting /no bonding agent, silane/ no bonding agent, non-treated/ etch-and-rinse; non-treated/one-step self-etch; non-treated/ two-step self-etch; sandblasting/etch-and-rinse; sandblasting/one-step self-etch; sandblasting/ two-step self-etch; silane coupling agent/etch-andrinse; silane coupling agent/ one-step self-etch; silane coupling agent/two-step self-etch. Micro shear testing was performed to bond strength assessment. Results: Two-way ANOVA and Tukey's test (α = 0.05) demonstrated significant difference between the surface treatments and adhesive systems. Only no treated surface/etchand-rinse group showed lower bond strength values when compared to other groups. Conclusion: The surface treatments were capable to increase the effectiveness of the repair in composite resin despite bonding agent used in untreated surfaces. The self-etching bonding agents were more effective on bonding to repair procedures when no surface treatment was performed. (AU)

Bonding of the silane containing multi-mode universal adhesive for lithium disilicate ceramics

OBJECTIVES: This study evaluated the influence of a multi-mode universal adhesive (MUA) containing silane (Single Bond Universal, 3M EPSE) on the bonding of resin cement to lithium disilicate. MATERIALS AND METHODS: Thirty IPS e.max CAD specimens (Ivoclar Vivadent) were fabricated. The surfaces were treated as follows: Group A, adhesive that did not contain silane (ANS, Porcelain Bonding Resin, Bisco); Group B, silane (S) and ANS; Group C, hydrofluoric acid (HF), S, and ANS; Group D, MUA; Group E, HF and MUA. Dual-cure resin cement (NX3, Kerr) was applied and composite resin cylinders of 0.8 mm in diameter were placed on it before light polymerization. Bonded specimens were stored in water for 24 hours or underwent a 10,000 thermocycling process prior to microshear bond strength testing. The data were analyzed using multivariate analysis of variance (p < 0.05). RESULTS: Bond strength varied significantly among the groups (p < 0.05), except for Groups A and D. Group C showed the highest initial bond strength (27.1 ± 6.9 MPa), followed by Group E, Group B, Group D, and Group A. Thermocycling significantly reduced bond strength in Groups B, C, and E (p < 0.05). Bond strength in Group C was the highest regardless of the storage conditions (p < 0.05). CONCLUSIONS: Surface treatment of lithium disilicate using HF and silane increased the bond strength of resin cement. However, after thermocycling, the silane in MUA did not help achieve durable bond strength between lithium disilicate and resin cement, even when HF was applied.

The Effect of Hydrofluoric Acid Concentration and Heat on the Bonding to Lithium Disilicate Glass Ceramic

Abstract The aim of this study was to evaluate the effects of hydrofluoric acid (HF) concentration and previous heat treatment (PHT) on the surface morphology and micro-shear bond strength (mSBS) of a lithium disilicate glass ceramic (EMX) to resin cement. One hundred four EMX specimens were randomly assigned to two groups (n=52) according to the HF concentration: 5% and 10%. A new random distribution was made according to the PHTs (n=13): control (no PHT); previously heated HF (70 °C); previously heated EMX surface (85 °C); the combination of heated HF + heated EMX surface. The etching time was set at 20 s. All EMX blocks were silanated and received a thin layer of an unfilled resin. Five resin cement cylinders were made on each EMX surface using Tygon tubes as matrices, and then stored for 24 h at 37 °C. One random etched EMX sample from each group was analyzed using field-emission scanning electron microscopy (FE-SEM). The data were subjected to two-way ANOVA and multiple comparisons were performed using the Tukey post hoc test (a=0.05). For the control groups, 5% HF showed statistically lower mSBS values when compared to 10% HF (p<0.05). PHT increased the mSBS values for 5% HF, yielding statistically similar results to non-PHT 10% HF (p<0.05). FE-SEM images showed increased glassy matrix removal when PHT was applied to HF 5%, but not to the same degree as for 10% HF. PHT has the potential to improve the bond strength of 5% HF concentration on lithium disilicate glass ceramic.

Resumo O objetivo deste estudo foi avaliar os efeitos das concentrações de ácido fluorídrico (AF) e do prévio tratamento térmico (PTT) na morfologia da superfície e resistência de união ao microcisalhamento (mRUM) de uma cerâmica vítrea de dissilicato de lítio (EMX) ao cimento resinoso. Cento e quatro espécimes de EMX foram aleatoriamente distribuídos em dois grupos (n=52) de acordo com a concentração do AF: 5% e 10%. Os espécimes foram novamente distribuídos de forma aleatória de acordo com o PTT (n=13): controle (sem PTT); AF previamente aquecido (70 °C); superfície do EMX previamente aquecida (85 °C); combinação entre AF e EMX aquecidos. O tempo de condicionamento foi fixado em 20 s. Todos os espécimes de EMX foram silanizados e receberam a aplicação de uma fina camada de um adesivo sem carga. Cinco cilindros de cimento resinoso foram confeccionados usando tubos Tygon como matrizes e então armazenados por 24 h a 37 °C. Uma amostra condicionada de cada grupo foi aleatoriamente selecionada e analisada em um microscópio eletrônico de varredura em emissão de campo (MEVEC). Os dados foram submetidos ao teste ANOVA de dois fatores e múltiplas comparações foram feitas pelo teste de Tukey (a=0.05). Para os grupos controle, AF 5% mostrou valor de mRUM estatisticamente menor do que AF 10% (p<0.05). PTT aumentou os valores de mRUM para o AF 5%, proporcionando resultados estatisticamente similares ao grupo AF 10% controle (p<0.05). MEVEC mostrou um aumento na remoção da matriz vítrea quando o PTT foi aplicado ao grupo AF 5%, no entanto esse efeito não foi visto no grupo AF 10%. O PTT tem o potencial de melhorar a resistência de união do AF 5% na cerâmica vítrea reforçada por disilicato de lítio.

Influence of Surface Treatments and Adhesive Systems on Lithium Disilicate Microshear Bond Strength

Abstract The purpose of this study was to evaluate the microshear bond strength of ceramic prosthetic structures reinforced by lithium disilicate cemented with resin cement under conditions of different surface treatments and adhesive systems. Seventy-two rectangular blocks of lithium disilicate (6.5 mm long × 5 mm wide × 1 mm thick) were fabricated, air abraded with 50-μm Al2O3 particles and divided into six groups (n=12) depending on the surface pretreatments. The groups were as follows: 10HF/S/SBM: 10% hydrofluoric acid etched for 20 s (10HF) + silane (S) + Adper Scotchbond Multi-Purpose (SBM); 10HF/S/SB: 10HF + S + Single Bond Universal (SB); 10HF/SBM; 10HF/SB; S/SBM and S/SB. Two 1-mm-long plastic tubes were placed on the specimens, filled with RelyX ARC resin cement and cured for 20 s per tube. The plastic tube was removed, and the microshear bond strength was tested. Data were submitted to analysis of variance and Tukey's tests (α=0.05). Fractured specimens were observed under optical microscopy. For both adhesives, the bond strengths (MPa) of groups treated with acid-etching and silane (10HF/S/SB: 24.82, 10HF/S/SBM: 24.90) were higher (p<0.001) than those of groups treated with acid-etching (10HF/SB: 16.47, 10HF/SBM: 19.94) only or only silane (S/SB: 18.42, S/SBM: 13.24). All groups showed a predominance of failure adhesive. The silanization should be a clinical step in cementing ceramic structures reinforced by lithium disilicate, even with the application of universal adhesive that contains silane in its formulation.

Resumo O objetivo neste estudo foi avaliar a resistência de união ao microcisalhamento de estruturas protéticas cerâmicas reforçadas por dissilicato de lítio cimentadas com cimento resinoso sob diferentes tratamentos de superfície e sistemas adesivos. Setenta e duas barras retangulares de dissilicato de lítio (6,5 mm de comprimento × 5 mm de largura × 1 mm de espessura) foram fabricadas, tratados com partículas de Al2O3 (50 μm) e dividido em seis grupos (n=12) dependendo dos pré-tratamentos de superfície. Os grupos foram como se segue: 10HF/S/SBM: condicionamento com ácido fluorídrico 10% durante 20 s (10HF) + silano (S) + Adper Scotchbond Multi-Purpose (SBM); 10HF/S/SB: 10HF + S + Single Bond Universal (SB); 10HF/SBM; 10HF/SB; S/SBM; e S/SB. Dois tubos plásticos cilíndricos de 1 mm de comprimento foram colocados sobre os espécimes, preenchidos com cimento RelyX ARC e fotoativado durante 20 s por tubo. Os tubos plásticos foram removidos e a resistência de união ao microcisalhamento foi testada. Os dados foram submetidos à análise de variância e ao teste de Tukey (α=0,05). Espécimes fraturados foram observados sob microscopia óptica. Para ambos os adesivos, a resistência de união (MPa) dos grupos tratados com condicionamento ácido e silano (10HF/S/SB: 24,82, 10HF/S/SBM: 24,90) foram superiores (p<0.001) aos grupos tratados com condicionamento ácido apenas (10HF/SB: 16,47, 10HF/SBM: 19,94) ou apenas silano (S/SB: 18,42, S/SBM: 13,24). Todos os grupos apresentaram uma predominância de falha adesiva. A silanização deve ser um passo clínico em cimentação de estruturas cerâmicas reforçadas por dissilicato de lítio, mesmo com a aplicação do adesivo universal que contém em sua formulação um silano.

Evaluation of microshear bond strength and nanoleakage of etch‑and‑rinse and self‑etch adhesives to dentin pretreated with silver diamine fluoride/potassium iodide: An in vitro study.

Aims: The aim of this in vitro study was to comparatively evaluate the microshear bond strength (MSBS) of etch‑and‑rinse and self‑etch (ER and SE) bonding systems to dentin pretreated with silver diamine fluoride/potassium iodide (SDF/KI) and nanoleakage at the resin‑dentin interface using transmission electron microscope (TEM). Subjects and Methods: Seventy‑two dentin slabs of 3 mm thickness were prepared from extracted human permanent third molars and divided into four groups (n = 18) based on the dentin surface treatment as follows: (1) ER adhesive bonding without dentin pretreatment; (2) SDF/KI pretreatment of dentin followed by ER adhesive bonding; (3) SE adhesive bonding without dentin pretreatment; and (4) SDF/KI pretreatment of dentin followed by SE adhesive bonding. Resin composite was built on the dentin slabs to a height of 4 mm incrementally, and dentin‑composite beams of approximately 1 mm2 cross‑sectional area were prepared. The beams were subjected to MSBS analysis, and the fractured surface was observed under scanning electron microscope to determine the mode of failure. The resin‑dentin interface was examined under TEM for evaluation of nanoleakage. Statistical Analysis Used: One‑way ANOVA followed by Tukey’s post hoc multiple comparison tests. Results: Pretreatment of dentin with SDF/KI increased the MSBS of ER and SE adhesives, though not statistically significant, except between Groups 2 and 3. In all the groups, the predominant mode of failure was adhesive followed by cohesive in resin, mixed and cohesive in dentin. TEM examination of resin‑dentin interface showed that pretreatment with 38% SDF/KI reduced nanoleakage regardless of the type of bonding system used. Conclusions: Pretreatment of dentin with SDF/KI minimized nanoleakage at the resin‑dentin interface without adversely affecting the bond strength of resin composite to dentin.

Effect of Fluoride and Simplified Adhesive Systems on the Bond Strength of Primary Molars and Incisors

The aim of this study was evaluate in vitro the influence of simplified adhesive systems (etch-and-rinse and self-etching) and 1.23% acidulated phosphate fluoride (APF) on the microshear bond strength (μ-SBS) of composite resins on primary molars and incisors. Forty primary molars and forty incisors vestibular enamel was treated with either the self-etching Clearfil SE Bond (CSE, Kuraray) or etch-and-rinse Adper Single Bond 2 (SB2, 3M/ESPE) adhesive system. Each group was subdivided based on the prior treatment of the enamel with or without the topical application of 1.23% APF. Thereafter, matrices were positioned and filled with composite resin and light cured. After storage in distilled water at 37±1°C for 24 h, the specimens were submitted to μ-SBS in a universal testing machine. Kruskal-Wallis and Mann-Whitney tests (p<0.05) showed that the prior application of 1.23% APF led to a significant reduction in bond strength. The type of adhesive exerted no significant influence bond strength. In the inter-group analysis, however, significantly bond strength reduction was found for the incisors when CSE was employed with APF. Adhesive failure was the most common type of fracture. The bond strength was affected by the prior application of 1.23% APF and type of tooth.

O objetivo deste estudo foi avaliar a influência dos sistemas adesivos simplificados (condicionamento ácido total e auto-condicionante) e fluorfosfato acidulado a 1,23% (FFA) na resistência de união ao microcisalhamento (μ-RUC) de resinas compostas em molares e incisivos decíduos. O esmalte vestibular de quarenta molares e quarenta incisivos decíduos foi tratado com Clearfil SE Bond (CSE, Kuraray) ou Adper Single Bond 2 (SB2, 3M/ESPE). Cada grupo foi subdividido com base no tratamento prévio do esmalte com ou sem aplicação tópica de FFA a 1,23%. Em seguida, matrizes foram posicionadas e preenchidas com resina composta e posterior fotopolimerização. Depois da armazenagem em água destilada a 37±1 °C por 24 h, os espécimes foram submetidos ao μ-RUC em uma máquina de ensaio universal. Teste Kruskal-Wallis e Mann-Whitney (p<0,05) mostraram que a aplicação prévia de FFA a 1,23% levou a uma redução significativa na resistência de união. O tipo de adesivo não exerceu influência significativa na resistência de união. Na análise intergrupos, entretanto, redução significativa na resistência de união foi encontrada para os incisivos quando CSE foi empregado sem FFA. Falha adesiva foi o tipo de fratura mais comum. A resistência de união foi afetada pela aplicação de FFA a 1,23% e tipo de dente.

Effect of water storage on microshear bond strength of four dental adhesive systems to dentin

AIM: To evaluate the microshear bond strength of 4 dental adhesive systems after 1 year-water storage. MATERIAL AND METHODS: The sample consisted of 120 cylinders of composite, obtained from 24 bovine incisors, which were divided into four experimental groups: G1-Scotchbond Multi-Purpose, G2-Single Bond 2, G3-Clearfil SE Bond, G4-Adper Easy One and two storage times in distilled water: T0 - 24h and T1 - 1 year. A bivariate analysis was performed using the ANOVA and Tukey test (α=0.05). Results were evaluated inter-and intra-group in both times. RESULTS: After 24 hours, G1T0 (39.68A ± 11.55) showed higher bond strength (MPa) followed by G2T0 (22.71B ± 4.07), G3T0 (18.94BC ± 7.29) and G4T0 (13.30C ± 3.94). After 1 year of storage only G1T1 (33.95A ± 6.35) and G3T1 (13.59BC ± 2.63) maintained the bond strength values (p ≥ 0.05), while G2T1 (10.62C ± 4.32) and G4T1 (4.49D ± 2.49) presented a decrease in this values. CONCLUSION: The hydrophobic two-step adhesive systems maintained the bond strength after 1-year water storage.

Microshear bonding effectiveness of different dentin regions.

Aim: The aim of this in vitro study was to evaluate the influence of dentin surfaces with different tubule orientation on bond strength of a multimode adhesive system. Materials and Methods: Twenty human molars were selected and prepared in different ways in order to produce different dentin regions. The teeth were randomized (n = 5) according to the application modes of a multimode adhesive system (etch‑and‑rinse and self‑etching) and to the dentin region (occlusal and proximal – 1.5 mm depth from dentinoenamel junction). Cylindrical restorations were performed on dentin with a starch tube. The samples remained immersed in distilled water for 24 h and the microshear bond strength (µSBS) test was performed. The µSBS values were expressed in MPa and analyzed with ANOVA and Tukey’s test (P < 0.05). Results: There was no significant difference in the bond strength values between the application modes of the adhesive system (P = 0.19); however, the dentin regions (P < 0.05) significantly affected the µSBS. The proximal dentin presented higher bond strength values than occlusal dentin. Conclusion: The dentin surfaces with different tubule orientation influenced the bonding effectiveness of the adhesive system tested.

Effects of Light-Curing on the Immediate and Delayed Micro-Shear Bond Strength between Yttria-Tetragonal Zirconia Polycrystal Ceramics and Universal Adhesive

PURPOSE: To evaluate the effect of light-curing on the immediate and delayed micro-shear bond strength (microSBS) between yttria-tetragonal zirconia polycrystal (Y-TZP) ceramics and RelyX Ultimate when using Single Bond Universal (SBU). MATERIALS AND METHODS: Y-TZP ceramic specimens were ground with #600-grit SiC paper. SBU was applied and RelyX Ultimate was mixed and placed on the Y-TZP surface. The specimens were divided into three groups depending on whether light curing was done after adhesive (SBU) and resin cement application: uncured after adhesive and uncured after resin cement application (UU); uncured after adhesive, but light cured after resin cement (UC); and light cured after adhesive and light cured resin cement (CC). The three groups were further divided depending on the timing of microSBS testing: immediate at 24 hours (UUI, UCI, CCI) and delayed at 4 weeks (UUD, UCD, CCD). microSBS was statistically analyzed using one-way ANOVA and Student-Newman-Keuls multiple comparison test (P0.05). At 4 weeks, microSBS of UUD group (24.43+/-2.88 MPa) had significantly increased over time compared to UUI group (P<0.05). The SEM results showed mixed failure in UCI and CCI group, while UUI group showed adhesive failure. CONCLUSION: Light-curing of universal adhesive before or after application of RelyX Ultimate resin cement significantly improved the immediate microSBS of resin cement to air-abrasion treated Y-TZP surface. After 4 weeks, the delayed microSBS of the non-light curing group significantly improved to the level of light-cured groups.

A study on the compatibility between one-bottle dentin adhesives and composite resins using micro-shear bond strength

OBJECTIVES: This study was performed to determine whether the combined use of one-bottle self-etch adhesives and composite resins from same manufacturers have better bond strengths than combinations of adhesive and resins from different manufacturers. MATERIALS AND METHODS: 25 experimental micro-shear bond test groups were made from combinations of five dentin adhesives and five composite resins with extracted human molars stored in saline for 24 hr. Testing was performed using the wire-loop method and a universal testing machine. Bond strength data was statistically analyzed using two way analysis of variance (ANOVA) and Tukey's post hoc test. RESULTS: Two way ANOVA revealed significant differences for the factors of dentin adhesives and composite resins, and significant interaction effect (p < 0.001). All combinations with Xeno V (Dentsply De Trey) and Clearfil S3 Bond (Kuraray Dental) adhesives showed no significant differences in micro-shear bond strength, but other adhesives showed significant differences depending on the composite resin (p < 0.05). Contrary to the other adhesives, Xeno V and BondForce (Tokuyama Dental) had higher bond strengths with the same manufacturer's composite resin than other manufacturer's composite resin. CONCLUSIONS: Not all combinations of adhesive and composite resin by same manufacturers failed to show significantly higher bond strengths than mixed manufacturer combinations.