Influência de diferentes silanos na resistência de união entre cerâmica de dissilicato de lítio e cimento resinoso / Influence of different silanes on the bond strength between lithium disilicate and resin cement

Objetivo: O objetivo do estudo foi avaliar o uso de diferentes marcas de silano na resistência de união entre a cerâmica de dissilicato de lítio e o cimento resinoso. A hipótese nula avaliada foi que as diferentes marcas de silanos apresentariam similar resistência de união. Métodos: Foram confeccionados 80 discos de dissilicato de lítio (IPS E.max CAD) com (12 mm x 1 mm). Após a cristalização, foram incluídos em tubos de PVC com resina acrílica e polidos com lixas de carbeto de silício, sob irrigação com água. Após aplicação de ácido hidrofluorídrico 10%, foram lavados e secos e divididos aleatoriamente em 4 grupos para aplicação do silano (n=20). S-Y: Yller; S-M: Monobond N; S-U: Ultradent; S-DS: Dentsply Sirona. Uma matriz de silicone com 4 orifícios foi confecionada e preenchida posteriormente com o cimento resinoso (Multilink N) para realização do teste de microcilhamento (EMIC) e os dados foram avaliados pelo teste one-way ANOVA. Resultados: Análise de variância mostrou que não houveram diferenças estatísticas nos valores médios entre os grupos de tratamento (p=0,404). A média e desvio padrão (DP) da resistência de união (MPa) nos grupos foram: S-Y: 26,9 (6,3); S-M: 28,3 (5,8); S-U: 29,0 (8,0); S-DS: 31,8 (11,0). Conclusões: As diferentes marcas de silano avaliadas apresentaram resistência de união similar entre si. Porém, a aplicação de silano é fundamental para obter melhorias na resistência de união(AU)

Objective: To evaluate the use of different brands of silane in the bond strength between lithium disilicate and resin cement. The null hypothesis evaluated was that the different brands of silanes would present similar bond strength. Methods: 80 lithium disilicate discs (IPS E.max CAD) were made with 12 mm in diameter x 1 mm in thickness. After crystallization, they were included in PVC tubes with acrylic resin and polished with silicon carbide sandpaper, under irrigation with water, creating a smooth and flat surface and randomly divided into 4 groups (n = 20). G1: Yller; G2: Monobond N; G3: Ultradent; G4: Dentsply Sirona. The samples were stored for 24h in distilled water for subsequent microcutting testing. One-way analysis of variance was used to obtain the results. Results: Analysis of variance showed that there were no statistical differences in the mean values between the treatment groups (p = 0.404). The mean and standard deviation (SD) of the bond strength (MPa) in the groups were: G1: 26.9 (6.3); G2: 28.3 (5.8); G3: 29.0 (8.0); G4: 31.8 (11.0). Conclusions: The different brands of silane evaluated showed similar bond strength. However, application of silane is essential to obtain improvements in bond strength(AU)

Different bonding agents effect on adhesive bond strength: lithium disilicate glass ceramic / Efeito de diferentes agentes de união na cimentação adesiva em superfície cerâmica de dissilicato de lítio

Introduction: The silanization of the ceramic surface prior to applying the adhesive and/or resinous materials plays an important role in bond strength. Nowadays, a new family of adhesive systems has been introduced into the market, aiming to simplify the technique of adhesive procedures during cementation. Objective: To investigate the effectiveness of different bonding agents containing silane and primer on Lithium Disilicate Glass Ceramic (LD) surface by shear bond strength tests. Material and method: 130 LD ceramic blocks were included in acrylic resin, polished and washed in ultrasound for 10 minutes. The specimens were divided into 2 groups according to surface treatment: Polished Surface (PS); Hydrofluoric Acid 9.5% - 20s (HF). Each group was divided into 5 subgroups (n = 13) according to bonding agent type: metallic primer containing MDP (ZPrimePlus, Bisco Inc); two traditional silanes (MonobondPlus, IvoclarVivadent / Porcelain Prime, Bisco Inc.); mixture of silane and resin (Kerr Silane, Kerr); mixture of silane and universal adhesive (Single-bond Universal, 3M Espe). The specimens were mounted in a standard device for shear testing (UltradentBonding Assembly), cemented with dual resin cement (RelyX UltimateTM, 3M Espe.) and photo-polymerized for 20s. The samples were tested after 24 hours and 3 months of storage in distilled water at ±36 °C. The data were analyzed by 3-Way Anova and Tukey's test (α = 5%). Result: Shear bond strength (SBS) was significantly influenced by surface treatment, bonding agent used and storage (p <0.001). Conclusion: Adequate adhesive bond strength to Lithium Disilicate Glass Ceramic can be obtained with traditional silanes, combined with HF acid pretreatment surface.

Introdução: A silanização da superfície cerâmica antes da aplicação do adesivo e/ou materiais resinosos desempenha um papel importante na resistência adesiva. Atualmente, uma nova família de sistemas adesivos foi introduzida no mercado, visando simplificar a técnica dos procedimentos adesivos durante a cimentação. Objetivo: Investigar a eficácia de diferentes soluções contendo silano e primer na superfície de cerâmicas de Dissilicato de Lítio (DLT) por meio de testes de resistência adesiva por cisalhamento. Material e método: 130 blocos cerâmicos DLT foram incluídos em resina acrílica, polidos e lavados em ultra-som por 10 minutos. Os espécimes foram divididos em 2 grupos de acordo com tratamento de superfície: Superfície Polida (PS); Ácido Hidro-Fluorídrico 9,5% - 20s (HF). Cada grupo foi dividido em 5 sub-grupos (n = 13) de acordo com o tipo de primer/silano: primer metálico contendo MDP (ZprimePlus, Bisco Inc); dois silanos tradicionais (MonobondPlus, IvoclarVivadent / Porcelain Prime, Bisco Inc.); mistura de silano e resina (Kerr Silane, Kerr); mistura de silano e adesivo universal (Single-bond Universal, 3M Espe). Os espécimes foram montados em um dispositivo padrão (UltradentBonding Assembly) para teste de cisalhamento Bisco Shear Bond Tester), cimentados com cimento resinoso dual (RelyX UltimateTM, 3M Espe.) e foto-polimerizados por 20s. O teste foi realizado após o período de: 24 horas e 3 meses de armazenamento em água destilada à ±36 °C. Os dados foram analisados por 3-Way Anova e Teste de Tukey (α=5%). Resultado: A resistência adesiva ao cisalhamento (SBS) foi significativamente influenciada pelo tipo de tratamento da superfície, pelo tipo de agente de união utilizado e pelo armazenamento (p<0,001). Conclusão: Adequada resistência adesiva pode ser obtida com silanos tradicionais, combinados com o pré-tratamento de superfície com ácido HF.

Does use of silane-containing universal adhesive eliminate the need for silane application in direct composite repair?

Abstract This in vitro study aimed to evaluate the effect of a silane-containing universal adhesive used with or without a silane agent on the repair bond strength between aged and new composites. Forty nanohybrid composite resin blocks were stored in distilled water for 14 d and thermo-cycled. Sandpaper ground, etched, and rinsed speciments were randomly assigned into four experimental groups: silane + two-step etch-and-rinse adhesive system, two-step etch-and-rinse adhesive system, silane + silane-containing universal adhesive system, and silane-containing universal adhesive system. Blocks were repaired using the same composite. After 24 h of water storage, the blocks were sectioned and bonded sticks were submitted to microtensile testing. Ten unaged, non-repaired composite blocks were used as a reference group to evaluate the cohesive strength of the composite. Two-way ANOVA and Tukey's tests were used to analyze average µTBS. One-way ANOVA and Dunnet post-hoc tests were used to compare the cohesive strength values and bond strength obtained in the repaired groups (α = 0.05). The µTBS values were higher for the silane-containing universal adhesive compared to the two-step etch-and-rinse adhesive system (p = 0.002). Silane application improved the repair bond strength (p = 0.03). The repair bond strength ranged from 39.3 to 65.8% of the cohesive strength of the reference group. Using universal silane-containing adhesive improved the repair bond strength of composite resin compared to two-step etch-and-rinse adhesive. However, it still required prior application of a silane agent for best direct composite resin repair outcomes.

Effect of different surface treatments and multimode adhesive application on the Weibull characteristics, wettability, surface topography and adhesion to CAD/CAM lithium disilicate ceramic

Abstract This paper aims to evaluate the effect of different surface treatments on surface topography, wettability, and shear bond strength of resin cement to glass ceramic. Methodology: For SBS test, 32 blocks (7x7x2 mm) of lithium disilicate were obtained and randomly divided into eight groups (four blocks per group) according to each surface treatment (HF 20 s, 60 s, 120 s + silanization/S or Scotch Bond Universal/ SBU) and the Monobond Etch & Prime - MEP application followed or not by SBU. On each treated surface ceramic block, up to four dual-curing resin cement cylinders were prepared and light-cured for 40s (N=120/n=15). The specimens were thermocycled (10,000 cycles, 5-55°C, 30 s) and the SBS test (50KgF, 0.5 mm/min) was performed. Furthermore, failure analysis, wettability, AFM, and SEM were carried out. SBS data (MPa) were analyzed using Student's t-test, two-way ANOVA, Tukey's test (5%) and Weibull's analysis. Results: For HF experimental groups, two-way ANOVA presented the factors "etching time" and "bonding agent" as significant (p<0.05). After silane application, the HF groups presented similar bond strength. SBU application compromised the SBS, except for 120s etching time (HF120sS: 23.39ᵃ±6.48 MPa; HF120sSBU: 18.76ᵃ±8.81MPa). For MEP groups, SBU application did not significantly affect the results (p=0.41). The MEP group presented the highest Weibull modulus (4.08A) and they were statistically different exclusively from the HF20sSBU (0.58B). Conclusion: The HF 20s, 60s, 120 s followed by silane, promoted similar resin-bond strength to ceramic and the SBU application after HF or MEP did not increase the SBS.

Reutilização da cerâmica de dissilicato de lítio para CAD/CAM: efeito do tratamento de superfície e do envelhecimento na durabilidade da união ao cimento resinoso / Reuse of lithium disilicate ceramics for CAD/CAM: effect of surface treatment and aging on the durability of the bond to resin cement

Objetivo: Investigar o efeito do reaproveitamento de blocos CAD/CAM de cerâmicas de dissilicato de lítio (DL), tratamento de superfície (ácido fluorídrico-HF ou Monobond Etch & Prime -MEP) e da termociclagem na resistência de união ao cimento resinoso. Materiais e métodos: 48 blocos de dissilicato de lítio (DL) (E.max CAD, Ivoclar Vivadent) foram confeccionados e sinterizados de acordo com o grupo experimental. Assim, para os grupos que utilizaram a cerâmica DL convencional (C), vinte e quatro blocos foram obtidos a partir da secção de blocos de CAD/CAM de DL nas dimensões de 14x12x2mm, os quais foram lixados (#600) e sinterizados em seguida. Já para os grupos que utilizaram a cerâmica de DL após reaproveitamento (R), 24 blocos encerados nas dimensões de 10x10x3mm, foram incluídos em revestimento e em seguida resíduos de blocos cerâmicos de DL não sinterizados foram prensados pela técnica de cera perdida. Após, os blocos foram incluídos em resina acrílica ativada quimicamente e divididos em 12 grupos (4 blocos por grupo) de acordo com os fatores: "Ciclos de reaproveitamento" (C e R) "tratamento de superfície" (HF20s e HF120s e Monobond etch&prime/MEP) e "termociclagem" (com e sem). Após o tratamento, em cada superfície de bloco tratada HF5% ou MEP, quatro cilindros (Ø2mm) de cimento resinoso dual (Allcem Dual, FGM) foram confeccionados e fotopolimerizados por 60s (N = 180 / n = 15). Metade das amostras de cada grupo foram submetidos a termociclagem (10.000 ciclos, 5-55°C, 30s) e em seguida submetidos ao ensaio de resistência de união ao cisalhamento (SBS- 100KgF, 1mm/min). Os dados de SBS (MPa) foram analisados através de ANOVA 2-fatores,para cada grupo e ANOVA 1 fator para superfície de tratamento. Teste de Tukey (5%) e análise de Weibull também foram realizadas. Resultados: ANOVA revelou que para a cerâmica convencional a termociclagem e tratamento de superfície foram significantes (P=0.0000) porém a interação entre eles não foi significativa (P=0.6799). Já para a cerâmica reaproveitada, a termociclagem (P=0.0000), o tratamento de superfície (P=0.0000) e a interação (P=0.0117) foram significantes. Maiores valores de SBS foram encontrados no grupo HF120s e MEP, tanto para a cerâmica convencional quanto na reaproveitada. Entretanto, na condição TC, o reaproveitamento reduziu a resistência adesiva de maneira significativa quando se condicionou a cerâmica com HF por 20 ou 120s. Já quando o MEP foi utilizado, a resistência de união não foi afetada pelo reaproveitamento ( C= 22.30 MPa; R= 20.39MPa). O módulo Weibull (m) não foi significativo (P=0.547), mas a resistência característica (σ0) variou entre os grupos experimentais (P=0.000). Conclusão: O reaproveitamento da cerâmica de dissilicato de lítio reduz a durabilidade da união ao cimento resinoso, exceto quando o tratamento de superfície da cerâmica é realizado com primer cerâmico auto-condicionante (AU).

Objective: To investigate the effect of reusing CAD / CAM blocks of lithium disilicate (DL) ceramics, surface treatment (hydrofluoric acid-HF or Monobond Etch & Prime -MEP) and thermocycling on the bond strength to resin cement. Materials and methods: 48 blocks of lithium disilicate (LD) (E.max CAD, Ivoclar Vivadent) were made and sintered according to the experimental group. Thus, for the groups that used conventional LD ceramics (C), twentyfour blocks were obtained from the section of LD / CAM blocks of LD in the dimensions of 14x12x2mm, which were sanded (# 600) and then sintered . For the groups that used LD ceramic after reuse (R), 24 blocks waxed in the dimensions of 10x10x3mm, were included in coating and then residues of non-sintered LD ceramic blocks were pressed by the lost wax technique. Afterwards, the blocks were included in chemically activated acrylic resin and divided into 12 groups (4 blocks per group) according to the factors: "Reuse cycles" (C and R) "surface treatment" (HF20s and HF120s and Monobond etch & prime / MEP) and "thermocycling" (with and without). After treatment, on each treated block surface, HF5% or MEP, four cylinders (Ø2mm) of dual resin cement (Allcem Dual, FGM) were made and photopolymerized for 60s (N = 180 / n = 15). Half of the samples from each group were subjected to thermocycling (10,000 cycles, 5-55 ° C, 30s) and then subjected to the shear bond strength test (SBS- 100KgF, 1mm / min). The SBS (MPa) data were analyzed using 2-factor ANOVA for each group and 1-factor ANOVA for the treatment surface. Tukey's test (5%) and Weibull's analysis were also performed. Results: ANOVA revealed that for conventional ceramics, thermocycling and surface treatment were significant (P=0.0000) but the interaction between them was not significant (P=0.6799). For reused ceramics, thermocycling (P=0.0000), surface treatment (P=0.0000) and interaction (P=0.0117) were significant. Higher SBS values were found in the HF120s and MEP group, both for conventional and reused ceramics. However, in the TC condition, the reuse reduced the adhesive strength significantly when the ceramic was conditioned with HF for 20 or 120s. When the MEP was used, the bond strength was not affected by the reuse (C = 22.30 MPa; R = 20.39MPa). The Weibull module (m) was not significant (P=0.547), but the characteristic resistance (σ0) varied between the experimental groups (P = 0.000). Conclusion: The reuse of the lithium disilicate ceramic reduces the durability of the bond to the resin cement, except when the ceramic surface treatment is carried out with self-conditioning silane (AU).

Avaliação do efeito de diferentes tratamentos de superfície e tipo de material adesivo na resistência de união de reparo de resina bulk fill envelhecida / The effect of different surface treatments and adhesive material on bond strength of aged bulk fill resin composite repair

O objetivo do presente estudo foi avaliar o efeito da asperização com ponta diamantada e o jateamento com óxido de alumínio (Al2O3) como tratamentos de superfície e diferentes protocolos adesivos, associados ou não ao uso do silano, no reparo da resina composta do tipo bulk fill envelhecida. Cento e cinquenta discos (10 mm x 1,2 mm) de resina composta foram fabricados utilizando a resina composta FiltekTM One Bulk Fill (3M ESPE) e fotoativados durante 20 s, utilizando o equipamento fotopolimerizador de LED (Valo, Ultradent Product Inc. South Jordan, EUA), com a emitância de 1200 mW/cm2. A superfície de todos os corpos de prova foi padronizada com uma sequência de lixas e então submetida a um processo de envelhecimento acelerado utilizando uma ciclagem térmica com um total de 5.000 ciclos, com banhos de 5°C e 55°C e tempo de imersão de 30s. Os corpos de prova foram divididos de acordo com o tratamento de superfície a ser realizado: sem tratamento (ST), asperização com ponta diamantada de granulação fina (A) e jateamento com partículas de Al2O3 (J). Em seguida, dentro de cada grupo, os corpos de prova foram aleatoriamente distribuídos em 5 subgrupos de acordo com o protocolo adesivo a ser realizado: sem adesivo (SA), Adper Single Bond 2 (SB), Single Bond Universal (SBU), Silano + Adper Single Bond 2 (S+SB) e silano (S), totalizando 15 grupos experimentais (n=10). Após a realização dos tratamentos de superfície e protocolos adesivos, foram confeccionados três cilindros de resina (1,0 mm de diâmetro e 1,0 mm de altura) utilizando a mesma resina composta bulk fill, os mesmos parâmetros e equipamento fotopolimerizador, para simular o reparo. Os corpos de prova foram armazenados por um período de 24 horas em água deionizada em estufa à 37°C e então submetidos ao teste de resistência de união ao microcisalhamento em máquina de ensaio universal com velocidade de 1 mm/min. A área da falha foi analisada com auxílio de um microscópio digital (50x de aumento) para determinação do padrão de fratura. Os dados obtidos foram analisados estatisticamente pelo teste Análise de Variância (ANOVA) a dois fatores e em seguida empregado o teste de Tukey (?=0,05). Os valores de resistência de união dos grupos que não receberam tratamento de superfície, independente do protocolo adesivo utilizado, foram inferiores e diferentes estatisticamente daqueles que foram submetidos aos tratamentos de superfície com ponta diamantada ou jateamento (p < 0,001). Quando realizada a asperização ou o jateamento o único protocolo adesivo a se diferenciar dos demais, com resultados estatisticamente inferiores foi o protocolo sem adesivo (SA) (p < 0,001). Não houve diferença estatística entre os grupos A/SB, A/SBU, A/S+SB e A/S e entre os grupos J/SB, J/SBU, JS+SB e J/S. O grupo J/SBU apresentou maiores valores de resistência de união que o grupo A/SBU (p < 0,001). Falhas coesivas no substrato envelhecido e mistas foram os padrões de fratura mais frequentes quando foi realizado o tratamento da superfície, enquanto falhas adesivas foi o padrão mais comum quando não foi realizado tratamento de superfície. Conclui-se que os tratamentos de superfície com ponta diamantada ou jateamento com Al2O3 melhoram os valores de resistência de união em um reparo de resina composta do tipo bulk fill e quando associados a utilização de qualquer um dos sistemas adesivos estudados, combinado ou não ao uso do silano, promovem uma boa resistência de união. A utilização do SBU resulta em um maior valor de resistência de união quando aplicado em superfícies tratadas com jateamento com Al2O3.

Influência do uso do silano na resistência de união e no padrão de fratura nos reparos da resina indireta Ceramage com a resina direta Filtek Z350 / Influence of silane on bond strength and fracture pattern for indirect resin Ceramage repair with direct resin Filtek Z350

Pouca informação encontra-se disponível sobre a influência dos diferentes tratamentos de superfície das restaurações de resina indireta na resistência de união com as resinas diretas usadas para reparo. O objetivo deste estudo foi avaliar a influência de diferentes técnicas com uso do silano no reparo da resina indireta Ceramage na resistência ao cisalhamento e no padrão de fratura com a resina composta direta Filtek Z350. Blocos de resina composta indireta Ceramage (SHOFU) foram confeccionados e envelhecidos por 3 semanas em água destilada à 37°C. Posteriormente, foram jateados com óxido de alumínio e distribuídos aleatoriamente em 4 grupos de 10. No grupo 1, a superfície da resina Ceramage recebeu o adesivo convencional Adper Single Bond 2 (3M ESPE). No grupo 2 foi aplicado adesivo universal Adper Single Bond Universal (3M ESPE). Nos grupos 3 e 4, foi feita a aplicação do silano Silano Mais (Dentsply Sirona) e dos adesivos convencional e universal respectivamente. Foram confeccionados cilindros de resina composta direta Filtek Z350 (3M ESPE) na superfície da resina indireta Ceramage em todos os espécimes. Em seguida foi feito o teste de cisalhamento na máquina de teste universal (EMIC) após o armazenamento dos espécimes em água destilada à 37°C por 24 horas. O estereomicroscópio foi utilizado para analisar as falhas. A análise estatística foi feita pelo teste estatístico de Kruskal-Wallis. Não houve uma diferença estatisticamente significativa (p>0,05) na resistência de união e no padrão de fratura entre as diferentes técnicas de aplicação do silano no tratamento de superfície. Concluiu-se que o uso do silano pode não ser imprescindível para aumentar a resistência de união do reparo da resina indireta Ceramage com a resina direta Filtek Z350. No entanto, clinicamente é provável que se tenha uma maior chance de sucesso no reparo com a aplicação do silano. (AU)

Just few information is available about the influence of different surface treatments of indirect resin restorations on bond strength to direct resins used for repair. The objective of this study was to evaluate the influence of different techniques with the use of silane on the shear bond strength and fracture pattern of indirect resin Ceramage to Filtek Z350 direct composite resin. Ceramage indirect composite blocks (SHOFU) were made and aged in distilled water at 37 ° C for 3 weeks. Subsequently, they were sandblasted with aluminum oxide and randomly divided into 4 groups of 10. In group 1, the surface of the Ceramage resin received the conventional adhesive Adper Single Bond 2 (3M ESPE). In group 2, Adper Universal Bond universal adhesive (3M ESPE) was applied. In groups 3 and 4, the Silano Mais silane (Dentsply Sirona) and the conventional and universal adhesives were applied respectively. Composite resins cylinder of Filtek Z350 (3M ESPE) were made on the surface of the indirect resin Ceramage in all specimens. The shear test was then performed on the universal test machine (EMIC) after their storage in destilled water at 37°C for 24 hours. The stereomicroscope was used to analyze the fractures. Statistical analysis was done by Kruskal-Wallis test. There were no statistically significant differences (p>0,05) in bond strength values and in fracture pattern between the different techniques of application of silane in surface treatment. It was concluded that the silane coupling agent would not be necessary for repairing indirect resin Ceramage with composte resin Filtek Z350. However, clinically it is likely to have a better chance of successful repair with silane application. (AU)

Effects of three silane primers and five adhesive agents on the bond strength of composite material for a computer-aided design and manufacturing system

Abstract Objective The objective of this study was to evaluate the effects of combinations of silane primers and adhesive agents on the bond strength of a composite block for a computer-aided design and manufacturing system. Material and Methods Three silane primers [Clearfil Ceramic Primer (CP), Super-Bond PZ Primer (PZ), and GC Ceramic Primer II (GP)] were used in conjunction with five adhesive agents [G-Premio Bond (P-Bond), Repair Adhe Adhesive (R-Adhesive), Super-Bond D-Liner Dual (SB-Dual), Super-Bond C&B (SB-Self), and SB-Dual without tributylborane derivative (SB-Light)]. The surface of a composite block (Gradia Block) was ground with silicon carbide paper. After treatment with a silane primer, a adhesive agent was applied to each testing specimen. The specimens were then bonded with a light-curing resin composite. After 24 h, the shear bond strength values were determined and compared using a post hoc test (α=0.05, n=8/group). We also prepared control specimens without primer (No primer) and/or without adhesive agent (No adhesive). Results PZ/SB-Dual and GP/SB-Dual presented the highest bond strength, followed by GP/P-Bond, CP/SB-Dual, CP/R-Adhesive, No primer/SB-Dual, GP/R-Adhesive, CP/P-Bond, No primer/R-Adhesive, PZ/R-Adhesive, CP/SB-Self, PZ/P-Bond, PZ/SB-Self, and GP/SB-Self in descending order of bond strength. No primer/P-Bond, No primer/SB-Self, and all specimens in the SB-Light and No adhesive groups presented the lowest bond strengths. Conclusion A dual-curing adhesive agent (SB-Dual) containing a tributylborane derivative in combination with a silane primer (GP or PZ) presents a greater bond strength between the composite block and the repairing resin composite than the comparators used in the study.

Influence of different treatments of the ceramic surface and thermal cycling on the bond strength of brackets to ceramic / Influência de diferentes tratamentos de superfície da cerâmica e ciclagem térmica na resistência de união de bráquetes à cerâmica

Objective: To evaluate in vitro the effect of different treatments of the ceramic surface and thermal cycling on the shear bond strength (SBS) of metallic brackets bonded to feldspathic ceramic. Material and method: Ceramic cylinders were divided into four groups (n=4) according to the treatment of ceramic surface: G1-Clearfil Ceramic Primer silane and Transbond XT (CCPT); G2-etched with 10% hydrofluoric acid (HFA) for 60 s, CCP and Transbond XT (ACCPT); G3-etched with 10% HFA for 60 s, Ambar Adhesive and Transbond XT (AAAT); and, G4 - etched with 10% HFA for 60 s, RelyX Ceramic Primer silane -RCP, adhesive primer Transbond and Transbond XT (ACPPT). Brackets were bonded to the cylinders with Transbond XT and light-activated for 40 s with LED Radii Plus. All specimens were stored in deionized water at 37 °C for 24 h, and two cylinders from each group were subject to 7,000 thermal cycles in a thermal cycler (5 °C/55 °C). After storage and thermal cycling, the SBS test was performed at a crosshead speed of 1 mm/min. Data were subjected to two-way ANOVA and Tukey's post hoc test (α=0.05). Result: The SBS of ACCPT was significantly higher than the other groups (p<0.05). The specimens submitted to thermal cycling showed significantly lower SBS than those without thermal cycling (p<0.05), regardless the ceramic surface treatment. The ARI showed predominance of score 0 for all groups. Conclusion: Acid etching, CCP silane and Transbond XT method obtained the best results for bracket bonding. Thermal cycling reduced SBS for all groups. Score 0 was predominant for ARI in all groups.

Objetivo: Avaliar in vitro o efeito de diferentes tratamentos de superfície da cerâmica e ciclagem térmica na resistência da união ao cisalhamento (RUC) de bráquetes metálicos colados na cerâmica felspática. Material e método: Cilindros cerâmicos foram separados em 4 grupos (n=4) de acordo com os tratamentos da superfície da cerâmica: G1-Clearfil Ceramic Primer silano e Transbond XT (CCPT); G-condicionamento com ácido hidrofluorídrico a 10% (AHF) por 60s, CCP e Transbond XT (ACCPT); G3-condicionamento com AHF a 10% por 60s, Adesivo Ambar e Transbond XT (AAAT); e, G4 condicionamento com AHF a 10% por 60s, RelyX Ceramic Primer silano, primer adesivo Transbond e Transbond XT (ACPAT). Os bráquetes foram fixados nos cilindros com Transbond XT e fotoativado por 40s com LED Radii Plus. Todas as amostras foram armazenadas em água deionizada a 37 °C por 24 h e dois cilindros de cada grupo foram submetidos a 7.000 ciclos térmicos na máquina para ciclagem térmica (5 °C/55 °C). Após armazenagem e ciclagem térmica, a RUC foi realizada à velocidade de 1 mm/min. Na Análise de Variância de 2 fatores e ao teste de Tukey's post hoc test (α=0,05) a RUC do G2 foi significante maior do que dos demais grupos (p<0,05). Resultado: As amostras submetidas à ciclagem térmica apresentaram valores de RUC significantemente menores do que as amostras sem ciclagem térmica (p<0,05), independente do tratamento de superfície da cerâmica. Conclusão: Nas condições desse estudo o melhor resultado para colagem foi obtido com o condicionamento, silano CCP e Transbond XT. A ciclagem térmica reduziu a RUC em todos os grupos.

A aplicação de um glaze na superfície de cimentação melhora a adesão da zircônia ao cimento resinoso? / Does the application of a glaze layer in the intaglio surface improve the adhesion between zirconia and resin cement?

Este trabalho teve como objetivo avaliar o efeito de diferentes tratamentos de superfície na resistência adesiva entre a interface zircônia/cimento resinoso. Blocos de zircônia (12 x 11,6 x 1,2 mm) foram divididos em cinco grupos (n=10) e classificados conforme o tratamento de superfície. Nas amostras em que a superfície não foi jateada, os filmes de glaze foram avaliados em função do condicionamento ou não das amostras com ácido fluorídrico (HF). No jateamento das superfícies das cerâmicas foram utilizadas microesferas de alumina, com e sem revestimento de sílica, e avaliada a influência dos tratamentos na resistência adesiva entre a superfície da cerâmica e o cimento resinoso. No teste de resistência de união, as amostras com glaze condicionado e com jateamento (alumina + sílica) apresentaram resultados superiores em relação às amostras não jateadas. As falhas foram classificadas em adesiva, mista e coesiva com a ajuda de um estereomicroscópio. A caracterização das superfícies foi avaliada por microscopia eletrônica de varredura e espectroscopia de energia dispersiva. A espessura dos filmes glaze, obtida pela micrografi a da secção transversal das amostras, apresentou espessuras semelhantes independentemente do tratamento. Os tratamentos de superfície da zircônia com glaze condicionado (com e sem secagem) e jateamento (alumina + sílica) obtiveram os melhores resultados de resistência de união.

This work aimed to evaluate the effect of different surface treatments on bond strength at the zirconia/resin cement interface. Zirconia blocks (12 x 11.6 x 1.2 mm) were divided into five groups (n=10) and classified according to the surface treatment. In the samples wherein the surface glaze has not been sandblasted the films were assessed for conditioning or not the samples with hydrofluoric acid (HF). Alumina microespheres with and without silica coating were used to blast the surfaces, and also to study the effect of treatments on bond strength between the ceramic surface and the resin cement. In the bond strength test samples with conditioning glaze and sandblasting (alumina + silica) showed higher scores than the non-blasted samples. The flaws were classified as adhesive, cohesive and mixed with the aid of a stereomicroscope. Surface characterization was evaluated by scanning electron microscopy and energy dispersive spectroscopy. The thickness of the glaze film obtained by the micrograph of the cross section of the samples showed similar thicknesses regardless of treatment applied. The zirconia surface treatments with conditioning glaze (with and without drying) and sandblasting (alumina + silica) generated the best bond strength results.

Influence of different surface treatments of fiberglass posts on the bond strength to dentin

Aim: To assess the influence of different fiberglass post surface treatments on the bond strength (BS) to root dentin. Methods: Thirty bovine root canals were endodontically treated and filled with gutta-percha and AH Plus sealer. At 24 h after the endodontic filling, the post spaces were prepared with Gates-Glidden drills and #3 drills of the DC White Post system, maintaining a 4 mm apical seal. The roots were randomly divided into three groups: S (fiberglass posts treated with silane), SA (fiberglass posts treated with silane and a hydrophobic adhesive system) and SHA (fiberglass posts treated with silane, followed by drying with hot air). The posts were cemented with a selfadhesive cement (RelyX U200). The specimens were stored in distilled water at 37 °C for 24 h and subjected to the push-out test (0.5 mm/min). Data were statistically analyzed using one-way ANOVA and Tukey's test (α=0.05) Results: SA and SHA groups showed the highest BS mean values (11.29 and 10.85 MPa, respectively), while the S group presented the lowest BS mean value (7.21 MPa). S group was significantly different from SA and SAH groups. Conclusions: The surface treatment of fiberglass posts influenced BS values (Au)

Influence of adhesive and thermal cycling on the bond strength of ceramic brackets to dental ceramic

Aim: This in vitro study investigated the effect of the application of an adhesive, silane and thermal cycling (TC) on the shear bond strength (SBS) of ceramic brackets to feldspathic ceramic. Methods: 16 cylinders of feldspathic ceramic were etched with hydrofluoric acid and divided into four groups (n=4): G1 - silane, without TC; G2 ­ silane, with TC; G3 - adhesive, without TC; G4 - adhesive, with TC. One layer of silane was applied on the surface of cylinders in G1 and G2 e one layer of photo-activated adhesive Single Bond Universal was used in G3 and G4. Ceramic brackets were bonded using Transbond XT. The SBS data were subjected to two-way ANOVA and Tukey's post hoc test (α=0.05). The Adhesive Remnant Index (ARI) was evaluated at 40× magnification. Results: Silane was more effective than adhesive on the SBS of the brackets to ceramic (p<0.05). TC decreased significantly the SBS values compared with the groups without TC (p<0.05). The ARI results showed predominance of score 0. Conclusions: Groups with silane showed higher SBS than groups with adhesive. TC influence significantly on the bond strength. Regarding ARI, score 0 predominated in all groups (Au)

Efeito da aplicação adicional de silano a um sistema adesivo universal sobre a resistência de união entre uma cerâmica reforçada por dissilicato de lítio e uma resina composta / Effect of adittional silane application to a universal adhesive system on the bond strength between a lithium disilicate ceramic and a composite resin

O objetivo deste estudo foi avaliar, por meio de ensaio de resistência ao microcisalhamento, o efeito da aplicação adicional de silano a um sistema adesivo universal na interface adesiva entre uma cerâmica reforçada por dissilicato de lítio e uma resina composta. Duzentos discos de IPS e.max Press/Ivoclar Vivadent (13x3mm) foram confeccionados, receberam acabamento com lixas de carbeto de silício (220-600) e limpeza com ácido fosfórico 37% (30s) imediatamente antes da aplicação do agente silano ou sistema adesivo. Sobre cada disco, foram confeccionados cinco cilindros de resina, o que totalizou mil cilindros de resina. O tratamento aplicado à superfície de cerâmica, anterior à inserção de resina foi realizada de acordo com cada um destes grupos: G1: 20s de ácido fluorídrico (HF) + silano (S) + Adper Single Bond 2/3M ESPE (SB); G2: 20s HF + S + Single Bond Universal/3M ESPE (U); G3: 20s HF + U; G4: 20s HF + S + Single Bond Universal misturado ao Otimizador para Cimentação/3M ESPE (OPC); G5: 20s HF + OPC; G6: S + SB; G7: S + U; G8: U; G9: S + OPC; G10: OPC. Os grupos G11 até o G20 receberam os mesmos tratamentos de superfície, mas foram submetidos à termociclagem de 10.000 ciclos. Os grupos G1 ao G10 foram levados à máquina de ensaio universal EMIC para o teste de microcisalhamento, enquanto os grupos G11 ao G20 foram submetidos à ciclagem térmica com banhos de 20s alternados em temperatura de 5ºC e 55ºC, para depois serem levados para o microcisalhamento. A análise estatística foi realizada através de análise de variância (ANOVA dois fatores), com nível de confiança de 95% (p=0,000) seguido pelo teste Post Hoc de Tukey. Os resultados demonstraram que todos os grupos condicionados por HF obtiveram valores de resistência de união significativamente mais elevados, enquanto a termociclagem apenas provocou diferença significativa entre os grupos de mesmo tratamento de superfície sem condicionamento prévio com HF e entre G1 e G11. O modo de fratura avaliado por microscopia ótica, microscopia eletrônica de varredura e a análise dos elementos químicos por EDS demonstrou o total de 24,3% de fraturas mistas; 74,5% de fraturas adesivas e 1,2% de fraturas coesivas. Pode-se concluir que a aplicação adicional prévia de silano aumentou a resistência de união entre o adesivo universal e a cerâmica e que o condicionamento com ácido fluorídrico foi fator determinante para obtenção de resultados mais altos, principalmente após a termociclagem.

The aim of this study was to evaluate, through a microshear bond strength test, the effect of an additional silane application before a universal adhesive system on the interface between a lithium disilicate ceramic system and a flowable resin. Two hundred IPS e.max Press/Ivoclar Vivadent discs (13x3mm) were made, abraded with sandpaper silicon carbide (220-600) and cleaned with 37% phosphoric acid (30s) immediatelly before application of silane agent or adhesive system. On each disc five resin cylinders were built, which summarized one thousand cylinders. The treatment applied to the ceramic surface previous to the resin insertion was performed according to each of these groups: G1: 20s hydrofluoric acid (HF) + silane (S) + Single Bond 2 / 3M ESPE (SB); G2: 20s HF + S + Single Bond Universal / 3M ESPE (U); G3: 20s HF + U; G4: 20s HF + S + Single Bond Universal mixed with Dual Cure Activator / 3M ESPE (OPC); G5: 20s HF + OPC; G6: S + SB; G7: S + U; G8: U; G9: S + OPC; G10: OPC. The groups from G11 to G20received the same surface treatment, but they were submitted to 10.000 thermal cycles. The G1 to G10 were taken to the universal testing machine EMIC for microshear test, while the G11 to G20 were subjected to thermal cycling with alternating baths of 20s at 5°C and 55°C temperature, and then were submitted to the microshear test. The statistical analysis was done with ANOVA with 95% confidence level (p = 0.000) and Tukey's post-hoc test. The results showed that all groups etched with HF had significantly higher bond strength values while thermocycling only caused significant difference between groups of the same surface treatment without prior etching with HF and between G1 and G11 groups. The fracture mode evaluated by optical microscopy, scanning electron microscopy and analysis of chemical elements by EDS demonstrated total of 24.3% of mixed fractures; 74.5% adhesive fractures and 1.2% of cohesive fractures. It can be concluded that the additional prior silane application increased the bond strength between the universal adhesive and ceramics, besides the etching with hydrofluoric acid was determining factor for obtaining higher results, especially after thermal cycling.

Efeitos de lasers de alta potência na superfície de cerâmicas vítreas de dissilicato de lítio e sua resistência de união à dentina humana / Effects of high power laser irradiation on lithium di-silicate glass ceramic surface and bond strength to human dentin

O objetivo desse estudo foi avaliar a eficiência da irradiação com lasers de alta potência e a influência da aplicação do silano previa ou posteriormente à irradiação com os lasers na resistência de união entre cerâmica vítrea de dissilicato de lítio, cimento resinoso e dentina humana. Foram confeccionados 50 espécimes tronco cônicos de cerâmica (n=10), divididos aleatoriamente em 5 grupos: 1- Controle Condicionamento com ácido hidrofluorídrico 10% por 1 min e aplicação do silano; 2- Er:YAG – irradiação com laser Er:YAG (200 mJ e 10 Hz), seguido do condicionamento com ácido hidrofluorídrico 10% por 1 min e aplicação do silano; 3- Silano + Er:YAG – Condicionamento com ácido hidrofluorídrico 10% por 1 min, aplicação do silano e irradiação com laser Er:YAG nos mesmo parâmetros do grupo anterior; 4- Nd:YAG – irradiação com laser Nd:YAG (120 mJ e 10 Hz), seguido de condicionamento com ácido hidrofluorídrico 10% por 1 min e aplicação do silano, 5- Silano + Nd:YAG -Condicionamento com ácido hidrofluorídrico 10% por 1 min, aplicação do silano e irradiação com laser Nd:YAG nos mesmo parâmetros do grupo anterior. Após os tratamentos os espécimes cerâmicos foram cimentados com cimento resinoso de presa dual à superfície de dentina de 50 molares humanos incluídos em resina acrílica ativada quimicamente. Após armazenamento por 24 h foi realizado o ensaio de tração em máquina de ensaios universais com célula de carga de 10 KgF e velocidade constante de 1mm/min. Os dados obtidos foram submetidos à ANOVA 2-fatores e teste de Dunnet (α=5%). A análise dos padrões de fratura foram analisadas em estereomicroscopio. Adicionalmente foram confeccionados 15 espécimes em cerâmica no formato cilíndrico, submetidos aos mesmo tratamentos dos grupos anteriores (n=3) e utilizados para análise do ângulo de contato e análise em microscópio eletrônico de varredura. O teste de Dunnet mostrou diferenças significativas entre o grupo controle (9,42 ± 2,27 MPa) e os grupos Er (19,25 ± 3,7 MPa) e ...

The aim of this study was to evaluate the efficiency of irradiation with high-power lasers and the influence of silane application before or after irradiation with lasers on the bond strength between lithium disilicate glass-ceramic, resin cement and human dentin. Fiftytruncated-cones ceramic specimens (n=10) were randomly divided into 5 groups: Control- etching with hydrofluoric acid 10% for 1 min and application of silane; 2- Er -Er:YAG laser irradiation (200 mJ and 10 Hz), followed by etching with hydrofluoric acid 10% for 1 min and application of silane; 3- Sil + Er - etching with hydrofluoric acid 10%for 1 min, silane application and irradiation with Er: YAG laser in the same parameters as the previous group; 4- Nd:YAG laser - irradiation with Nd: YAG laser (120 mJ and 10 Hz), followed by etching with hydrofluoric acid 10% for 1 min and application of thesilane, 5- Sil + Nd- Etching with hydrofluoric acid 10% for 1 min, silane application and irradiation with Nd: YAG laser on the same parameters as the previous group. After treatment, the ceramic specimens were cemented with dual cure resin cement to the dentin of 50 human molars included in acrylic resin. After storage for 24 h it wassubmitted to tensile test in a universal testing machine with 10 kgf load cell andconstant speed of 1 mm/min. Data were submitted to ANOVA 2-way and Dunnet test (α = 5%). The analysis of fracture patterns were analyzed in stereomicroscope. In addition were made 15 ceramic specimens in cylindrical shape, subjected to the sametreatment of the above groups (n = 3) and used for analysis of the contact angle analysis and scanning electron microscope. The Dunnet test showed significant differences between Control group (9.42 ± 2.27 MPa) and Er group (19.25 ± 3.7 MPa) and Sil + Er (14.11 ± 4.11 MPa). ANOVA 2-way (p <5%) for Laser Type (p <0.0001) and Technical of Silanization (p = 0.0002) showed significant differences for bothfactors, but not for their interaction. ...

Efeitos de lasers de alta potência na superfície de cerâmicas vítreas de dissilicato de lítio e sua resistência de união à dentina humana / Effects of high power laser irradiation on lithium di-silicate glass ceramic surface and bond strength to human dentin

O objetivo desse estudo foi avaliar a eficiência da irradiação com lasers de alta potência e a influência da aplicação do silano previa ou posteriormente à irradiação com os lasers na resistência de união entre cerâmica vítrea de dissilicato de lítio, cimento resinoso e dentina humana. Foram confeccionados 50 espécimes tronco cônicos de cerâmica (n=10), divididos aleatoriamente em 5 grupos: 1- Controle Condicionamento com ácido hidrofluorídrico 10% por 1 min e aplicação do silano; 2- Er:YAG – irradiação com laser Er:YAG (200 mJ e 10 Hz), seguido do condicionamento com ácido hidrofluorídrico 10% por 1 min e aplicação do silano; 3- Silano + Er:YAG – Condicionamento com ácido hidrofluorídrico 10% por 1 min, aplicação do silano e irradiação com laser Er:YAG nos mesmo parâmetros do grupo anterior; 4- Nd:YAG – irradiação com laser Nd:YAG (120 mJ e 10 Hz), seguido de condicionamento com ácido hidrofluorídrico 10% por 1 min e aplicação do silano, 5- Silano + Nd:YAG -Condicionamento com ácido hidrofluorídrico 10% por 1 min, aplicação do silano e irradiação com laser Nd:YAG nos mesmo parâmetros do grupo anterior. Após os tratamentos os espécimes cerâmicos foram cimentados com cimento resinoso de presa dual à superfície de dentina de 50 molares humanos incluídos em resina acrílica ativada quimicamente. Após armazenamento por 24 h foi realizado o ensaio de tração em máquina de ensaios universais com célula de carga de 10 KgF e velocidade constante de 1mm/min. Os dados obtidos foram submetidos à ANOVA 2-fatores e teste de Dunnet (α=5%). A análise dos padrões de fratura foram analisadas em estereomicroscopio. Adicionalmente foram confeccionados 15 espécimes em cerâmica no formato cilíndrico, submetidos aos mesmo tratamentos dos grupos anteriores (n=3) e utilizados para análise do ângulo de contato e análise em microscópio eletrônico de varredura. O teste de Dunnet mostrou diferenças significativas entre o grupo controle (9,42 ± 2,27 MPa) e os grupos Er (19,25 ± 3,7 MPa)...

The aim of this study was to evaluate the efficiency of irradiation with high-power lasers and the influence of silane application before or after irradiation with lasers on the bond strength between lithium disilicate glass-ceramic, resin cement and human dentin. Fiftytruncated-cones ceramic specimens (n=10) were randomly divided into 5 groups: Control- etching with hydrofluoric acid 10% for 1 min and application of silane; 2- Er -Er:YAG laser irradiation (200 mJ and 10 Hz), followed by etching with hydrofluoric acid 10% for 1 min and application of silane; 3- Sil + Er - etching with hydrofluoric acid 10%for 1 min, silane application and irradiation with Er: YAG laser in the same parameters as the previous group; 4- Nd:YAG laser - irradiation with Nd: YAG laser (120 mJ and 10 Hz), followed by etching with hydrofluoric acid 10% for 1 min and application of thesilane, 5- Sil + Nd- Etching with hydrofluoric acid 10% for 1 min, silane application and irradiation with Nd: YAG laser on the same parameters as the previous group. After treatment, the ceramic specimens were cemented with dual cure resin cement to the dentin of 50 human molars included in acrylic resin. After storage for 24 h it wassubmitted to tensile test in a universal testing machine with 10 kgf load cell andconstant speed of 1 mm/min. Data were submitted to ANOVA 2-way and Dunnet test (α = 5%). The analysis of fracture patterns were analyzed in stereomicroscope. In addition were made 15 ceramic specimens in cylindrical shape, subjected to the sametreatment of the above groups (n = 3) and used for analysis of the contact angle analysis and scanning electron microscope. The Dunnet test showed significant differences between Control group (9.42 ± 2.27 MPa) and Er group (19.25 ± 3.7 MPa) and Sil + Er (14.11 ± 4.11 MPa). ANOVA 2-way (p <5%) for Laser Type (p <0.0001) and Technical of Silanization (p = 0.0002) showed significant differences for bothfactors, but not for their interactio...

Effects of plasma on polyethylene fiber surface for prosthodontic application

ABSTRACT Plasma technology has the potential to improve the adherence of fibers to polymeric matrices, and there are prospects for its application in dentistry to reinforce the dental particulate composite. Objectives This study aimed to investigate the effect of oxygen or argon plasma treatment on polyethylene fibers. Material and Methods Connect, Construct, InFibra, and InFibra treated with oxygen or argon plasma were topographically evaluated by scanning electron microscopy (SEM), and chemically by X-ray photoelectron spectroscopy (XPS). For bending analysis, one indirect composite (Signum) was reinforced with polyethylene fiber (Connect, Construct, or InFibra). The InFibra fiber was subjected to three different treatments: (1) single application of silane, (2) oxygen or argon plasma for 1 or 3 min, (3) oxygen or argon plasma and subsequent application of silane. The samples (25x2x2 mm), 6 unreinforced and 60 reinforced with fibers, were subjected to three-point loading tests to obtain their flexural strength and deflection. The results were statistically analyzed with ANOVA and the Bonferroni correction for multiple comparison tests. Results SEM analysis showed that oxygen and argon plasma treatments promote roughness on the polyethylene fiber surface. X-ray photoelectron spectroscopy (XPS) analysis shows that both plasmas were effective in incorporating oxygenated functional groups. Argon or oxygen plasma treatment affected the flexural strength and deflection of a fiber reinforced composite. The application of silane does not promote an increase in the flexural strength of the reinforced composites. Conclusions Oxygen and argon plasma treatments were effective in incorporating oxygenated functional groups and surface roughness. The highest strength values were obtained in the group reinforced with polyethylene fibers treated with oxygen plasma for 3 min.

Effect of composite surface treatment and aging on the bond strength between a core build-up composite and a luting agent

Objective The purpose of this study was to assess the influence of conditioning methods and thermocycling on the bond strength between composite core and resin cement. Material and Methods Eighty blocks (8×8×4 mm) were prepared with core build-up composite. The cementation surface was roughened with 120-grit carbide paper and the blocks were thermocycled (5,000 cycles, between 5°C and 55°C, with a 30 s dwell time in each bath). A layer of temporary luting agent was applied. After 24 h, the layer was removed, and the blocks were divided into five groups, according to surface treatment: (NT) No treatment (control); (SP) Grinding with 120-grit carbide paper; (AC) Etching with 37% phosphoric acid; (SC) Sandblasting with 30 mm SiO2 particles, silane application; (AO) Sandblasting with 50 mm Al2O3 particles, silane application. Two composite blocks were cemented to each other (n=8) and sectioned into sticks. Half of the specimens from each block were immediately tested for microtensile bond strength (µTBS), while the other half was subjected to storage for 6 months, thermocycling (12,000 cycles, between 5°C and 55°C, with a dwell time of 30 s in each bath) and µTBS test in a mechanical testing machine. Bond strength data were analyzed by repeated measures two-way ANOVA and Tukey test (α=0.05). Results The µTBS was significantly affected by surface treatment (p=0.007) and thermocycling (p=0.000). Before aging, the SP group presented higher bond strength when compared to NT and AC groups, whereas all the other groups were statistically similar. After aging, all the groups were statistically similar. SP submitted to thermocycling showed lower bond strength than SP without thermocycling. Conclusion Core composites should be roughened with a diamond bur before the luting process. Thermocycling tends to reduce the bond strength between composite and resin cement. .

Efeitos do condicionamento ácido, do tipo de silano e da ciclagem térmica na resistência ao cisalhamento de braquetes fixados à cerâmica / Effects of acid etching, type of silane and thermocycling on shear bond strength of brackets bonded to ceramic

Esta pesquisa avaliou a resistência de união ao cisalhamento de braquetes metálicos (Rocky Mountain Orthodontics) fixados à cerâmica, variando condicionamento ácido, aplicação do silano e ciclagem térmica. Quanto ao silano, comparou-se o Clearfil Ceramic Primer, que contém um monômero ácido em sua formulação, com o Rely X Ceramic Primer, desprovido do monômero. Foram confeccionados 120 discos em cerâmica IPS Empress Esthetic (Ivoclar) com 8 mm de diâmetro por 5 mm de espessura e separados em oito grupos (n=15): Grupos 1, 2, 5 e 6: ácido fluorídrico a 10% por um minuto; Grupos 1 a 4: silano com monômero ácido; Grupos 5 a 8: silano sem monômero ácido; Grupos 1, 3, 5 e 7: 1.000 ciclos de 5°C e 55°C, 30 segundos cada banho. Em seguida, os braquetes foram fixados à cerâmica com o compósito Transbond XT e fotoativados com luz emitida por diodo (LED – UltraLume 5), com 1100 mW/cm2. As amostras foram estocadas em água destilada a 37°C por 24 horas e submetidas ao teste de resistência ao cisalhamento em uma máquina de ensaio Instron à velocidade de 0,5 mm/min. Os dados foram submetidos à análise de variância e ao teste de Tukey (p < 0,05). Obtiveram significância estatística o aumento da adesividade com o condicionamento ácido e a redução de resistência com a ciclagem térmica. Na comparação entre os silanos, não houve diferença estatisticamente significante. Todos os experimentos atingiram valores de resistência superiores aos estabelecidos para uso clínico.

This study evaluated the shear bond strength of metallic brackets (Rocky Mountain Orthodontics) bonded to ceramic, varying acid etching, silane application, and thermocycling. Concerning silane, Clearfil Ceramic Primer, which contains an acid monomer in its formulation, was compared to Rely X Ceramic Primer, devoid of this monomer. 120 IPS Empress Esthetic (Ivoclar) ceramic disks were made with a diameter of 8 mm and thickness of 5 mm. The specimens were divided into eight groups (n=15): Groups 1, 2, 5, 6: hydrofluoric acid 10% for one minute; Groups 1 to 4: silane with acid monomer; Groups 5 to 8: silane without acid monomer; Groups 1, 3, 5, 7: thermocycled 1,000 times at 5°C and 55°C for 30 seconds. After that, the brackets were bonded to the ceramic with Transbond XT composite and cured with light-emitting diode (LED – Ultralume 5) at 1100 mW/cm². All samples were stored in distilled water at 37°C for 24 hours and submitted to shear bond strength test in an Instron testing machine at a crosshead speed of 0.5 mm/min. The data were submitted both to Anova and Tukey’s Test (p < 0,05). Statistical significance was found both in the adhesiveness increase with the acid etching as well as in the resistance decrease with thermocycling. By comparing the silanes, no statistical significance was found. All the experiments reached shear bond strength values higher than those established for clinical use.

Adhesive bonding of resin composite to various titanium surfaces using different metal conditioners and a surface modification system

Objective: This study evaluated the effect of three metal conditioners on the shear bond strength (SBS) of a prosthetic composite material to cpTi grade I having three surface treatments. Material and Methods: One hundred sixty eight rivet-shaped specimens (8.0x2.0 mm) were cast and subjected to polishing (P) or sandblasting with either 50 mm (50SB) or 250 mm (250SB) Al2O3. The metal conditioners Metal Photo Primer (MPP), Cesead II Opaque Primer (OP), Targis Link (TL), and one surface modification system Siloc (S), were applied to the specimen surfaces, which were covered with four 1-mm thick layers of resin composite. The resin layers were exposed to curing light for 90 s separately. Seven specimens from each experimental group were stored in water at 37ºC for 24 h while the other 7 specimens were subjected to 5,000 thermal cycles consisting of water baths at 4ºC and 60ºC (n=7). All specimens were subjected to SBS test (0.5 mm/min) until failure occurred, and further 28 specimens were analyzed using scanning electron microscope (SEM) and X-ray energy-dispersive spectroscopy (EDS). Data were analyzed by 3-way ANOVA followed by post-hoc Tukey's test (α=0.05). Results: On 50SB surfaces, OP groups showed higher SBS means than MPP (P<0.05), while no significant difference was found among OP, S, and TL groups. On 250SB surfaces, OP and TL groups exhibited higher SBS than MPP and S (P<0.05). No significant difference in SBS was found between OP and TL groups nor between MPP and S groups. The use of conditioners on 250SB surfaces resulted in higher SBS means than the use of the same products on 50SB surfaces (P<0.05). Conclusion: Sandblasting associated with the use of metal conditioners improves SBS of resin composites to cpTi. .

Chemical treatment of the intra-canal dentin surface: a new approach to modify dentin hydrophobicity

Objective: This study evaluated the hydrophobicity of dentin surfaces that were modified through chemical silanization with octadecyltrichlorosilane (OTS). Material and Methods: An in vitro experimental study was performed using 40 human permanent incisors that were divided into the following two groups: non-silanized and silanized. The specimens were pretreated and chemically modified with OTS. After the chemical modification, the dentin hydrophobicity was examined using a water contact angle measurement (WCA). The effectiveness of the modification of hydrophobicity was verified by the fluid permeability test (FPT). Results and Conclusions: Statistically significant differences were found in the values of WCA and FPT between the two groups. After silanization, the hydrophobic intraradicular dentin surface exhibited in vitro properties that limit fluid penetration into the sealed root canal. This chemical treatment is a new approach for improving the sealing of the root canal system.