Micro-shear bond strength of composite resin to glass ionomer cement using an alternative method to build up test specimens.

CONTEXT: Despite the relevance of the sandwich technique, there are still doubts about the best adhesive strategy and surface treatment for glass ionomer cements (GICs). AIM: The aim of this study is to evaluate the best surface treatment for GIC to ensure an effective and durable adhesion to resin, through micro-shear test, using an alternative method to build up test specimens. SUBJECTS AND METHODS: Eighty GIC samples were divided into eight groups (n = 10) according to five surface treatments (none, etching, air drying, grinding, and grinding plus etching) and according to the adhesive system (conventional or self-etch). Five starch tubes were positioned on each sample, and a flowable composite was inserted generating 50 resin test bodies per group and a total of 400 tested areas. All specimens were submitted to the micro-shear test: half immediately and half after thermal cycling (10,000 cycles of 20 s each/5° and 55°C). All samples were analyzed to evaluate fracture. Representative samples were also analyzed by scanning electron microscopy and energy dispersive spectroscopy. Data were analyzed with two-way ANOVA and Tukey's honest significant difference post hoc test (P <.05). RESULTS: The bond strengths in the thermal cycled specimens were lower and showed a statistically significant difference (P = 0). The "grinding" groups showed the highest bond strength. CONCLUSIONS: The alternative method to build up test specimens was effective and easy to execute. Grinding of the GIC surface, which is not normally performed before the use of the adhesive system, represented the best option of surface treatment.

Effect of prior silane application on the bond strength of a universal adhesive to a lithium disilicate ceramic.

STATEMENT OF PROBLEM: Universal adhesives combine silane and various monomers in a single bottle to make them more versatile. Their adhesive performance is unclear. PURPOSE: The purpose of this in vitro study was to assess the effects of an additional silane application before using a universal adhesive on the adhesion between a disilicate glass ceramic and a composite resin by using a microshear bond strength test (µSBS) and fracture analysis immediately and after thermocycling. MATERIAL AND METHODS: One hundred lithium disilicate glass ceramic disks were divided into 10 groups for bond strength testing according to the following 3 surface treatments: silane application (built-in universal adhesive or with additional application), adhesive (Adper Single Bond Plus [SB, 3M ESPE], Scotchbond Universal Adhesive [U, 3M ESPE], and mixed U with Dual Cure Activator [DCA, 3M ESPE]); or thermocycling (half of the specimens were thermocycled 10000 times). After surface treatment, 5 resin cylinders were bonded to each disk and submitted to a µSBS test. The failure mode was analyzed under a stereomicroscope and evaluated by scanning electron microscope and energy-dispersive x-ray spectroscopy. Data from the µSBS test were analyzed by 3-way ANOVA followed by the Tukey HSD post hoc test (α=.05). RESULTS: An additional silane application resulted in a higher µSBS result for all adhesive groups (P<.05). CONCLUSIONS: Ceramic surface treatment influenced the performance of adhesives, which may be improved with an additional silane application.

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.

Harmonização do sorriso com lentes de contato dental: relato de caso clínico / Harmonization of the smile with “contact lenses”: a case report

A odontologia moderna busca restaurações invisíveis que mimetizem os dentes naturais e que sejam confeccionadas com o mínimo prejuízo dos tecidos dentais. Nesse contexto, as lentes de contato dentais são excelentes opções restauradoras, quando bem indicadas, pois requerem pouco desgaste de estrutura dental e devolvem anatomia, forma, textura, cor e harmonia aos dentes envolvidos. Além disso, as cerâmicas têm excelente longevidade clínica quando aderidas ao esmalte dental. O presente artigo tem como objetivo descrever um caso clínico de fechamento de diastema e harmonização do sorriso com laminados cerâmicos de pequena espessura, e demonstra o protocolo conservador dessa técnica restauradora.

Modern dentistry seeks for invisible restorations that mimic natural teeth, with minimal damage to dental tissues. In this context, “contact lens” veneers are an excellent restorative option, when correctly indicated, as they require little wear of tooth structure and restore anatomy, shape, texture, color and harmony to the teeth involved. Furthermore, ceramics have excellent clinical longevity when bonded to tooth enamel. The aim of this work is to describe a clinical case of diastema closure and harmonization of the smile with thin ceramic laminates, demonstrating a conservative protocol of this restorative technique.

Surface roughness of different composite resins subject to in-office bleaching.

This study used atomic force microscopy to evaluate the effects of an in-office dental bleaching protocol on the surface roughness of 3 resins: microfilled, microhybrid, and nanofilled. Two disks of each resin were prepared and evaluated. Twenty-four areas (5 x 5 µm) were scanned using an atomic force microscope. Then, each disk was treated with 35% hydrogen peroxide activated by a light emitting diode. After bleaching, the disks were scanned again. Data from the 24 areas before and after bleaching were evaluated qualitatively using topographical and 3-dimensional images, as well as profile lines. Quantitatively, roughness data (mean roughness and root mean square) were statistically evaluated using standard ANOVA and Student-Newman-Keuls tests (P < 0.05). The bleaching procedure increased roughness for each resin analyzed. Based on the results, it was concluded that in-office bleaching with 35% hydrogen peroxide-based gel significantly increased the surface roughness of microfilled, microhybrid, and nanofilled resins.

Condicionamento de superfícies na Odontologia com plasma de argônio: uma revisão de literatura / Conditioning surfaces in Dentistry with argon plasma: a literature review

O objetivo deste estudo foi de verificar, por meio de revisão de literatura, os resultados do tratamento de diferentes superfícies de interesse para a Odontologia com gás argônio, um plasma frio à pressão atmosférica. Este vem sendo recentemente estudado e aplicado com o intuito de aumentar a molhabilidade do substrato condicionado, como zircônia, um material conhecidamente ácido resistente; dentina e pinos de fibra de vidro, interferindo positivamente na adesão. Diferentes estudos foram revisados, podendo-se concluir que o condicionamento com plasma frio de argônio alterou a superfície dos substratos testados, aumentando a área de superfície e, com isso, reduzindo o ângulo de contato. Isto contribui para uma maior molhabilidade do substrato e aumento da adesão às superfícies testadas.

The aim of this study was to verify, by means of literature review, the results of treatment of different areas of interest to Dentistry with Argon gas, a cold atmospheric pressure plasma. This subject has recently been studied and applied in order to increase the wettability of the substrate conditioning as zirconia, a well known acid-resistant material; Pins and dentin fiberglass positively interfering in adhesion. Different studies were reviewed, and shall be concluded that conditioning with cold argon plasma altered the surface of substrates, increasing the surface area and thereby reducing the contact angle. This contributes to a greatter wettability of the substrate and increased adherence to surfaces tested.

Solventes do Primer: revisão de literatura / Primer Solvents: literature review

O aperfeiçoamento dos agentes adesivos contendo diferentes solventes e os avanços no tratamento da dentina resultaram em crescentes forças de adesão entre dentina e resina. O primer de forma isolada ou combinada com o adesivo está dissolvido em solventes como acetona, álcool e água. Os solventes respondem pela diluição do monômero e na evaporação da água remanescente na superfície dentinária facilitando assim a formação da camada híbrida. Nem água nem resíduos do próprio solvente devem permanecer na intimidade da dentina desmineralizada, pois ambos irão propiciar inadequada polimerização dos monômeros resinosos contidos no primer ou na resina fluida, aplicada posteriormente. Diferentes solventes são responsáveis por diferentes metodologias de aplicação e formas de tratamento.

The improvement of adhesives containing different solvents and advances in the treatment of dentin resulted in bond strengths between dentin and higher resin. The "primer" in isolation or combined with the adhesive is dissolved in solvents such as acetone, water and Alcohol Free. Solvents works on the dilution of the monomer and the evaporation of water remaining on the dentin surface thus facilitating the formation of the hybrid layer. No water or solvent residues itself must remain in the intimacy of demineralized dentin, since both will provide inadequate polymerization of resin monomers contained in the "primer" or fluid resin, applied later. Different solvents are responsible for differents application methodologies e and treatments.

Avaliação da influência de um gel a base de peróxido de hidrogênio a 35 porcento sobre a rugosidade superficial de três resinas compostas fotopolimerizáveis de diferentes tamanhos médios de partículas / Evaluation of influence of a gel-based hydrogen peroxide 35% on the surface roughness of three composite resins of different sizes of particles

O clareamento dental se firmou na odontologia como o meio disponível mais simples, comum e conservador de devolver o padrão de cor almejado pelos pacientes. O processo clareador consiste em um ataque a superfície do substrato dentário, provocando pequenas alterações através da quebra de pigmentos, que são longas cadeias de carbono, originando cadeias moleculares cada vez menores até que possam ser eliminadas por difusão. Considerando-se a prática clínica diária nota-se que, algumas vezes, o agente clareador entra em contato com materiais restauradores que ali se encontram, como as resinas compostas por exemplo. Tal procedimento pode ocasionar a indicação de substituição da resina em boas condições clínicas, devido à diferença de cor entre o dente clareado e o compósito. Porém, há casos, como por exemplos: restaurações posteriores e manutenção de clareamento, em que a cor não seria fator decisivo para uma intervenção clínica sobre a restauração. Este estudo avaliou, através de microscopia de força atômica, o efeito de um protocolo de clareamento dentário de consultório a base de peróxido de hidrogênio 35% sobre a rugosidade superficial de três resinas de tamanhos de partículas diferentes (micro-híbrida, microparticulada e nanoparticulada). Vinte e quatro imagens de 5 X 5μm selecionadas aleatoriamente e geradas por microscopia de força atômica foram analisadas estatisticamente por ANOVA e pelo teste SNK (p< 0,05). A análise das topografias demonstrou a resina microparticulada com a menor rugosidade inicial (Rq: 19,22μm e Ra: 14,95μm) e final (Rq: 28,66μm e Ra: 23,06μm), sendo a final semelhante estatisticamente a nanoparticulada inicial (Rq: 29,60μm e Ra: 23,75μm). Seguiram a micro-híbrida inicial (Rq: 35,45μm e Ra: 26,22μm) e a nanoparticulada final (Rq: 40,22μm e Ra: 31,49μm). A resina micro-híbrida final apresentou a maior rugosidade (Rq: 47,41μm e Ra: 36,45μm). Um aumento uniforme e proporcional da rugosidade de superfície nas três resinas testadas foi...

The bleaching has been in dentistry as the simplest, common and conservative way to return of the pattern of color desired by the patients. The bleaching consists in an attack on dental surface breaking pigments, which are long chains of carbon, causing molecular chains ever smaller until it can be eliminated by diffusion. Considering the practice daily, the bleaching agent contacts restorative materials, such as composite resins for example. This procedure can appoint the replacement of the resin in good clinical conditions due the difference in color between the cleared tooth and composite. But there are cases, for examples: posterior restoratives and maintenance of bleaching, in which color would not be decisive factor for a clinical intervention on the restoration. This study evaluated, through atomic force microscopy, the effect of a memorandum of an in office dental bleaching by hydrogen peroxide 35% on the surface roughness of three types of resins of different sizes of particles (micro-hybrid, microparticles and nanoparticles). Twenty four images of 5 X 5μm randomly selected and generated by atomic force microscopy, were statistically analyzed by ANOVA and the SNK test (p< 0.05). The analysis of topographies showed the microfilled resin with lower initial roughness (Rq: 19.22μm and Ra: 14.95μm) and final roughness (Rq: 28.66μm and Ra: 23.06μm), with the final roughness statistically similar to initial roughness of nanoparticles resin (Rq: 29.60 μm and Ra: 23.75μm). Followed the initial roughness of micro-hybrid resin (Rq: 35.45 μm and Ra: 26.22 μm) and the final roughness of nanoparticles resin (Rq: 40.22μm e Ra: 31.49μm). The final roughness of micro-hybrid resin had the highest roughness (Rq: 47.41 μm and Ra: 36.45 μm). An uniform and proportional increase of surface roughness of the three resins tested was found. A second stage of the study evaluated the same area of surface before and after the procedure simulator of bleaching and the result was...