Influência do selamento dentinário imediato com sistema adesivo universal na resistência de união / Influence of immediate dentin sealing on dentin bond strength with universal adhesive system

Resumo Introdução O selamento dentinário imediato consiste na aplicação imediata de um sistema adesivo sobre exposições dentinárias após o preparo dental e previamente aos procedimentos de moldagem. Objetivo O objetivo do estudo foi avaliar a influência do selamento dentinário imediato (SDI) na resistência adesiva do sistema adesivo universal (Single Bond Universal, 3M ESPE) em dentina, na forma de aplicação autocondicionante. Material e método 30 incisivos bovinos foram divididos em 3 grupos (n = 10): grupo S (Sem Selamento Dentinário Imediato), grupo SDI (Selamento Dentinário Imediato) e grupo SDIF (Selamento Dentinário Imediato + Resina Flow). A superfície vestibular foi desgastada com pontas diamantadas até a exposição superficial de dentina. A simulação da lama dentinária foi realizada com lixa d'água por 30s e a dentina tratada de acordo com o respectivo grupo. Para simulação da restauração provisória, foram cimentados blocos de resina bisacrílica com cimento de óxido de zinco. Após 7 dias, foi realizada a cimentação definitiva de blocos de resina com cimento resinoso dual (RelyX ARC, 3M ESPE). Os espécimes foram seccionados para obtenção de filetes de 1mm2 e submetidos ao teste de microtração, em uma máquina universal de ensaios (Instron). Os resultados foram tabulados e submetidos a Análise de Variância (ANOVA) e teste de Tukey a 5% de significância. Resultado Observaram-se maiores valores de resistência de união para o grupo SDIF (23,53 MPa), diferindo estatisticamente do Grupo S (17,65 MPa) (p=0,008). O grupo SDI apresentou valor médio de resistência de união (19,25 MPa), não diferindo estatisticamente dos grupos S (p=0,68) e SDIF (p=0,07). Conclusão Recomenda-se a técnica de selamento dentinário imediato seguido da uma camada de resina flow, em exposições dentinárias ocasionadas pelo preparo dental para restaurações indiretas.

Abstract Introduction Imediate dentin sealing (IDS) is a procedure where a dentin adhesive is applied on the exposed dentin surfaces after its preparation to indirect restorations and before impression procedures. Objective The objective of the study was to evaluate the effectiveness of the immediate dentin sealing technique (SDI) in adhesive resistance, using the Universal adhesive system (Single Bond Universal, 3M ESPE). Material and method 30 bovine incisors were selected and divided into 3 groups (n = 10): Groups S (Without Immediate Dentin Seal), SDI (Immediate Dentin Seal with Adhesive) and SDIF (Immediate Dentin Seal with Adhesive + Flow Resin). The vestibular surface was worn with diamond-tipped conical tips until superficial dentin exposure. The smear layer simulation was carried out with # 600 granulation sandpaper for 30s and the dentin was treated according to the respective group. To simulate the temporary restoration, blocks of bisacrylic resin were cemented with zinc oxide cement. After 7 days, the final cementation of resin blocks with dual resin cement (RelyX ARC, 3M ESPE) was carried out. The specimens were sectioned to obtain 1mm2 fillets and subjected to the microtensile test. Result The ANOVA test showed a statistical difference between the groups evaluated. Higher values of bond strength were observed for the SDIF group (23.53 MPa), differing statistically from Group S (17,65 MPa) (p = 0.008). The SDI group showed an average bond strength (19.25 MPa), which did not differ statistically from groups S (p = 0.68) and SDIF (p = 0.07). Conclusion Based on the results, it is recommended the immediate dental sealing technique with adhesive + flow resin in dental exposures caused in the dental preparation for indirect restorations.

Seria o YouTube uma fonte confiável de informação sobre clareamento dental no Brasil? / Would YouTube a reliable source of information about dental bleaching in Brazil?

Resumo Introdução O clareamento dental é um procedimento amplamente realizado, levando a uma procura de informação pelos pacientes, sendo que uma dessas fontes são os vídeos do YouTube. Objetivo: Avaliar a qualidade das informações contidas nos vídeos do YouTube sobre clareamento dental no Brasil. Material e método Uma busca no YouTube foi realizada com a frase "clareamento dental". Os primeiros 100 vídeos foram selecionados e visualizados na íntegra por dois examinadores, e parâmetros gerais foram registrados. Para avaliar a qualidade das informações, duas análises foram realizadas, avaliando a utilidade e a confiabilidade das informações. O teste de Mann-Whitney foi utilizado para avaliar e comparar a qualidade das informações. Resultado Dos 100 vídeos selecionados, 22 foram excluídos por não se adequarem aos critérios de seleção, restando 78 vídeos. Sobre a utilidade dos vídeos, 65,4% foram classificados como não úteis, 26,9% pouco úteis, 6,4% moderadamente úteis e apenas 1,3% muito útil. Sobre a confiabilidade dos vídeos, 94% não utilizaram fontes confiáveis de informação e 69% das informações não se apresentaram equilibradas e imparciais. Por outro lado, 60% dos vídeos exibiram informações claras e objetivas. Conclusão Atualmente, o YouTube não é uma fonte adequada de informações para pacientes sobre clareamento dental no Brasil. Sobre a qualidade dos vídeos, a maioria não se apresentou como satisfatória para os critérios de confiabilidade e utilidade. Os dentistas são a melhor fonte de conteúdo para clareamento dental. Entretanto os vídeos mais populares são de leigos e normalmente abordam receitas caseiras de clareamento dental.

Abstract Introduction Dental Bleaching is a widely procedure in dental practice, conducting patients to search for information and one of these sources of information it is videos from YouTube. Objective: Evaluate quality of information in videos from YouTube about dental bleaching in Brazil. Material and method: YouTube search for "dental bleaching" was performed. Theses videos are watched in full and categorized for two examinators. Reliability and usefulness were used to value the quality of information. Mann-Whitney test was used in statical analysis. Result The first 100 videos were examined for exclusion criteria and 22 were excluded, yielding 78 videos. About Usefulness of videos 65,4% were classified as non useful, 26,9% little useful, 6,4% moderately useful and just 1,3% as very useful. About reliability of videos 94% non used reliable sources of information, 69% of information was not balanced and impartial. However 60% of videos showed clear and objective information. Conclusion Actually YouTube was not a appropriate of information for patients about dental bleaching in Brazil. About quality of the videos, majority was not satisfactory for useful and reliability criteria. Dentists are the better source of information about dental bleaching, however most popular videos were from independent users e normally approaching homemade techniques of bleaching.

Bulk-Fill Composite Restorations Step-by-Step Description of Clinical Restorative Techniques Case Reports / Restauraciones compuestas Bulk-Fill Descripción paso a paso de las técnicas de restauración clínica Informes de casos

ABSTRACT Composite resins are excellent materials for direct restorations in the posterior region, satisfactorily reestablishing esthetics and function. Recently, a new class of composites has been commercialized, the so-called Bulk-fill resins. These resins may be inserted in the dental cavity in increments of 4 to 5 mm thick, and have the advantages of reducing polymerization shrinkage and clinical working time. The aim of this case report was to describe the use of bulk-fill composite resins to restore Class I and Class II cavities by means of two different restorative techniques.

RESUMEN Las resinas compuestas son excelentes materiales para restauraciones directas en la región posterior, restableciendo satisfactoriamente la estética y la función. Recientemente, se ha comercializado una nueva clase de compuestos, las denominadas resinas Bulk Fill. Estas resinas pueden insertarse en la cavidad dental en incrementos de 4 a 5 mm de espesor, y tienen las ventajas de reducir la contracción de la polimerización y el tiempo de trabajo clínico. El objetivo de este informe de caso fue describir el uso de resinas Bulk fill para restaurar las cavidades de Clase I y Clase II mediante dos técnicas de restauración diferentes.

Esthetic Rehabilitation of Retained Primary Teeth-A Conservative Approach.

With the advancement in ceramic restorations bonded to tooth structure, the treatment has become a feasible and conservative option to restore teeth with alteration in shape when owing to high demand in esthetics, with or without minimum tooth preparation. This article describes a report of a 32-year-old woman who was dissatisfied with her smile. The patient reported that she still had deciduous teeth, and that the maxillary lateral incisors had been restored with direct resin composite to correct the teeth shape. After discussing the restorative possibilities, a decision was made to place all-ceramic crowns (lithium disilicate glass-ceramic) with minimal tooth preparation, which figures as a conservative full-coverage approach. An esthetic outcome resembling a natural-looking smile resulted in the patient's satisfaction. Bonding of all-ceramic crowns onto minimally prepared deciduous teeth figures as a conservative treatment in case of partial anodontia, which decreases the chance of root resorption induced by trauma and benefits from good adhesion to enamel.

Influence of Teeth Preparation Finishing on the Adaptation of Lithium Disilicate Crowns.

The polishing step of teeth preparations for crowns is a step often performed, so that there is an increased time during the clinical procedure. The aim of this study is to evaluate the marginal and internal adaptation of all-ceramic CAD/CAM lithium disilicate crowns in polished preparations for crown and nonpolished preparations for crowns. For this purpose, 20 first molars were selected, which were divided into two groups (n = 10) G1, teeth that received surface roughening similar to preparation without polishing, and G2 (control), polished preparations. After the preparations were completed the teeth were scanned (Cerec Bluecam, Sirona, Bensheim, Germany), and the crowns were designed and machined using CAD/CAM technology (Sirona, Bensheim, Germany). The adaptation of the pieces was evaluated using polyvinyl siloxane replicas and stereomicroscope photographs with 70x magnifications. The normality test indicated a nonnormal result, so a Man-Whitney nonparametric test was performed. One out of the 24 measured regions showed a statistically significant difference (p = 0.0494). With this study it can be concluded that crowns fabricated by CAD/CAM technology performed on unpolished preparations are not influenced by the internal marginal adaptation and the ceramic part and are different from polished preparations.

Técnica semidireta: abordagem prática e eficaz para restauração em dentes posteriores / Semidirect technique: practical and effective approach to restoration in posterior teeth

Introdução: Embora as restaurações diretas tenham boas propriedades mecânicas, quando utilizadas sem indicação em cavidades amplas ficam susceptíveis a fratura e ao desgaste. Nesses casos, o ideal é que sejam feitas restaurações indiretas do tipo inlay ou onlay, entretanto o custo da etapa laboratorial das restaurações indiretas limitam a realização dessa técnica. Para tentar minimizar o custo e melhorar as propriedades da técnica direta existe as restaurações semidiretas. Objetivo: Descrever na forma de Um caso clínico a confecção de uma restauração do tipo onlay pela técnica semidireta. Relato de caso: Paciente compareceu a clínica odontológica para substituição de restauração insatisfatória no elemento 46. O tratamento de escolha foi substituição da restauração de resina composta por uma restauração do tipo onlay. A técnica semidireta foi eleita para confecção da restauração, uma vez que agrega as vantagens das técnicas direta e indireta, com um menor custo operacional e tempo de execução. Conclusão: A técnica semidireta é uma opção de tratamento para restaurações em dentes posteriores, com menor custo para o paciente e pode ser seguramente indicada em cavidades amplas (AU).

Introduction: Although direct restorations have good mechanical properties when used without large cavities indicated they are susceptible to fracture and wear. In such cases, the ideal is that indirect restorations of inlay or onlay type are carried out, however the cost of the laboratory stage of indirect restorations limit the realization of this technique. To attempt to minimize the cost and improve the properties of the direct technique exists semidiretas restorations. Objective: To describe the form of a clinical case the making of a restoration type onlay by semidirect technique. Case report: Patient attended the dental clinic for poor restoration replacing the element 46. The treatment of choice was replacement of the composite resin restoration by a restoration of the onlay type. The semi-direct technique was chosen to construct the restoration as it adds the advantages of direct and indirect techniques with a lower cost and execution time. Conclusion: The semidirect technique is a treatment option for restorations in posterior teeth, with less cost to the patient and can be safely displayed in large cavities (AU).

Compósitos em incisivos lateriais conoides: ciência e arte / Composite resin restorations in peg-shaped lateral incisors: science and art

A presença de incisivos laterais conoides compromete a harmonia do sorriso. O presente artigo tem como objetivo apresentar um relato de caso de reanatomização de laterais conoides, com consequente fechamento dos diastemas anterossuperiores e restabelecimento de guia canina. Entre as opções de tratamento optou-se pela restauração direta com resina composta por apresentar-se como o método que melhor se adaptou às expectativas e anseios da paciente. Ao final, o processo resultou em um sorriso esteticamente agradável não somente em termos dentais, mas também com relação à face da paciente, proporcionando um aspecto harmonioso e natural ao sorriso...

Diastema and peg-shaped teeth may compromise patient’s smile harmony. This article presents a case report of reshaping peg-shaped lateral incisors and subsequent closure of the maxillary anterior spacing and reestablishment of the canine guidance. Among the treatment options, direct resin composite restoration was selected because it was the treatment that best adapted to the expectations and desires of the patient. An excellent result was achieved with an aesthetically pleasing smile not only in dental terms, but also in relation to the face of the patient...

Modeling and validation of a 3D premolar for finite element analysis / Modelagem e validação 3D de um premolar para análise de elementos finitos

Introduction: The development and validation of mathematical models is an important step of the methodology of finite element studies. Objective: This study aims to describe the development and validation of a three-dimensional numerical model of a maxillary premolar for finite element analysis. Material and method: The 3D model was based on standardized photographs of sequential slices of an intact premolar and generated with the use of SolidWorks Software (Dassault, France). In order to validate the model, compression and numerical tests were performed. The load versus displacement graphs of both tests were visually compared, the percentage of error calculated and homogeneity of regression coefficients tested. Result: An accurate 3D model was developed and validated since the graphs were visually similar, the percentage error was within acceptable limits, and the straight lines were considered parallel. Conclusion: The modeling procedures and validation described allows the development of accurate 3D dental models with biomechanical behavior similar to natural teeth. The methods may be applied in development and validation of new models and computer-aided simulations using FEM.

Introdução: O desenvolvimento e validação de modelos matemáticos é uma importante etapa da metodologia de estudos de elementos finitos. Objetivo: Este estudo tem o objetivo descrever o desenvolvimento e validação de um modelo numérico tridimensional de um pré-molar superior para análise em elementos finitos. Material e método: Fotografias padronizadas de cortes sequenciais de um pré-molar hígido serviram de referência para o desenvolvimento do modelo 3D, que foi construído por meio do programa SolidWorks (Dassault, França). A fim de validar o modelo testes de compressão e simulação numérica foram realizados. Os gráficos de carga versus deslocamento de ambos os ensaios foram comparados visualmente, a percentagem de erro calculada e homogeneidade dos coeficientes de regressão testada. Resultado: Um modelo 3D preciso foi desenvolvido e validado, uma vez que os gráficos apresentavam-se visualmente semelhantes, o percentual de erro ficou dentro dos limites aceitáveis e as retas foram consideradas paralelas. Conclusão: Os procedimentos de modelagem e validação descritos permitem o desenvolvimento de modelos dentários 3D precisos com comportamento biomecânico semelhante aos dentes naturais. Os métodos podem ser aplicados no desenvolvimento e validação de novos modelos e estudos de simulações computacionais por meio do MEF.

Clinical evaluation of different desensitizing agents in home-bleaching gels.

STATEMENT OF PROBLEM: The influence of different compositions of desensitizing agents in whitening gels should be evaluated. PURPOSE: The purpose of this clinical trial was to compare the effectiveness of 4 carbamide peroxide (CP)-based bleaching gels containing desensitizing agents regarding the degree of bleaching, tooth sensitivity, degree of participant satisfaction, and gingival irritation. MATERIAL AND METHODS: The maxillary arch of the 50 participants was bleached using a split mouth, home-bleaching technique. The participants were divided into 2 groups: G1, 10% CP (Opalescence PF; Ultradent Products, Inc) (right) and 10% CP (Power Bleaching 10%; BM4) (left); and G2, 15% CP (Opalescence PF) (right) and 16% CP (Power Bleaching 16%) (left). Each gel was used in a 2-hour daily regimen for 45 days. The shade of the 6 maxillary anterior teeth was recorded with a shade guide and spectrophotometer at baseline, and after 15, 30, 45, and 180 days of treatment. Statistical differences were analyzed with ANOVA for repeated measures followed by the Bonferroni and Student t tests (α=.05). Tooth sensitivity was evaluated with a visual analog scale (rated on a 0 to 10 scale). Participant satisfaction was evaluated by using participant reports of their personal satisfaction or dissatisfaction with the shade. Gingival irritation was evaluated using the Löe index scores. RESULTS: Color change was found to be statistically significant for all treatment periods evaluated, both by the objective and the subjective analyses, regardless of the composition and the concentration of the bleaching agent (P<.001). After 45 days, all participants were satisfied with the shade obtained. No clinically diagnosed gingival irritation was noted. Neither of the 10% CP products caused sensitivity during treatment, and 16% CP containing 3% potassium oxalate showed lower sensitivity than 15% CP containing potassium nitrate. CONCLUSION: The association of 3% potassium oxalate with fluoride was effective in reducing tooth sensitivity during and after bleaching, particularly with the 16% CP product, and did not compromise the effectiveness of treatment.

Microtensile bond strength of a universal adhesive to deepdentin / Resistência de união de um sistema adesivo universal aplicado em dentina profunda

This study evaluated the microtensile bond strength of a universal adhesive system applied to deep dentin under different bonding strategies.Material and Methods: Fifteen human third molar shad the coronal portion removed exposing deep dentin and were assigned into 3 groups according to the adhesive system: G1(control): 2-steps totaletch(Adper Single Bond 2, 3M ESPE); G2: 1-stepself-etch universal adhesive (Scotchbond Universal,3M ESPE); G3:2 steps total-etch universal adhesive(Scotchbond Universal, 3M ESPE). Composite build up swere performed on the dentin surfaces and after water storage for 24 h, teeth were sectioned to obtain40 bonded beams per group with sectional areaof 0.9 mm2. The specimens were submitted to the microtensile bond strength (μTBS) test until failure.Statistical analyses were computed using one-wayANOVA (p = 0.05). Results: The mean μTBS (inMPa) were G1 = 22.27, G2 = 22.85 and G3 = 20.3.After statistical analysis, no significant differences were observed among the groups. Conclusions:Universal adhesive system performed similarly tothe total-etch adhesive and was not affected by theadhesion strategy...

O estudo avaliou a resistência de união à microtração de um sistema adesivo universal aplicado em dentina profunda sob diferentes estratégias adesivas. Material e Métodos: 15 terceiros molares tiveram a porção coronária removida,expondo dentina profunda, sendo então divididos em 3 grupos de acordo com o sistema adesivo: G1 (controle) sistema adesivo convencional de 2 passos e condicionamento ácido total (Adper SingleBond 2, 3M ESPE); G2: sistema adesivo universal,1 passo, autocondicionante (Scotchbond Universal,3M ESPE); G3: sistema adesivo universal, 2 passos e condicionamento ácido total (Scotchbond Universal,3M ESPE). As porções coronárias foram reconstruídas em resina composta e após 24 h em água destilada os espécimes foram seccionados para obtenção de 40 filetes por grupo. Os filetes foram submetidos ao teste de microtração à velocidade de 0,5 mm/min e os dados analisados estatisticamente. Results:Não foram observadas diferenças estatísticas entre os grupos, sendo as médias de resistência de união(MPa): G1 = 22,27, G2 = 22,85 and G3 = 20,3.Conclusão: O sistema adesivo universal apresentou performance similar ao sistema adesivo convencional e seu desempenho não foi afetado pela estratégia adesiva utilizada...

Silanization effect on microtensile bond strength of a self-adhesive luting material to a disilicate-based glass ceramic

Introduction: The rehabilitation of teeth by means of ceramic indirect restorations has been widely performed. Previous studies has shown the effectiveness of silane coupling agents on improving the bond strength of the adhesion of resin cements to ceramics; however, some studies question the use of silane. Objective: To evaluate the effect of silane application on the microtensile bond strength of an auto-adhesive luting material to a lithium disilicate glass-ceramic. Material and methods: Two blocks (9x11x4mm) of lithium disilicate glass-ceramic had one of their surfaces polished (# 220, 360, 600 grit silicon-carbide abrasive papers) and cleaned ultrasonically. The ceramic blocks were then divided into two groups according to the surface treatment: G1 (control group): etched with 10% hydrofluoric acid for 20s and silane coated; G2: etched with 10% hydrofluoric acid for 20s. After building two blocks of composite resin (Filtek Z350) with the same dimensions of the ceramic blocks, the self-adhesive resin cement (SpeedCEM) was applied directly to the ceramic surface and the resin block was seated on the cement. After storage (24h, 37°C), the ceramic-cement-composite blocks were cut with an Isomet low-speed diamond saw machine producing sticks, which were loaded to failure at a crosshead speed of 0.5 mm/min. The type of fracture was analyzed under an optical microscope. The results were statistically analyzed using the Student t test. Results: The mean microtensile and standard deviations in megaPascals were: G1 = 21.32 (± 4.36) and G2 = 16.55 (± 4.92). Statistical analysis showed that the bond strength was not significantly affected by the surface treatment with silane. Most of the fractures occurred within the adhesion zone. Conclusion: The application of silane had no significant effect on the bond strength between lithium disilicate glass-ceramic and self-adhesive resin cement.

Effect of ceramic thickness and composite bases on stress distribution of inlays--a finite element analysis.

The purpose of this study was to determine the effect of cavity depth, ceramic thickness, and resin bases with different elastic modulus on von Mises stress patterns of ceramic inlays. Tridimensional geometric models were developed with SolidWorks image software. The differences between the models were: depth of pulpal wall, ceramic thickness, and presence of composite bases with different thickness and elastic modulus. The geometric models were constrained at the proximal surfaces and base of maxillary bone. A load of 100 N was applied. The stress distribution pattern was analyzed with von Mises stress diagrams. The maximum von Mises stress values ranged from 176 MPa to 263 MPa and varied among the 3D-models. The highest von Mises stress value was found on models with 1-mm-thick composite resin base and 1-mm-thick ceramic inlay. Intermediate values (249-250 MPa) occurred on models with 2-mm-thick composite resin base and 1-mm-thick ceramic inlay and 1-mm-thick composite resin base and 2-mm-thick ceramic inlay. The lowest values were observed on models restored exclusively with ceramic inlay (176 MPa to 182 MPa). It was found that thicker inlays distribute stress more favorably and bases with low elastic modulus increase stress concentrations on the internal surface of the ceramic inlay. The increase of ceramic thickness tends to present more favorable stress distribution, especially when bonded directly onto the cavity without the use of supporting materials. When the use of a composite base is required, composite resin with high elastic modulus and reduced thickness should be preferred.

Effect of Ceramic Thickness and Composite Bases on Stress Distribution of Inlays - A Finite Element Analysis

The purpose of this study was to determine the effect of cavity depth, ceramic thickness, and resin bases with different elastic modulus on von Mises stress patterns of ceramic inlays. Tridimensional geometric models were developed with SolidWorks image software. The differences between the models were: depth of pulpal wall, ceramic thickness, and presence of composite bases with different thickness and elastic modulus. The geometric models were constrained at the proximal surfaces and base of maxillary bone. A load of 100 N was applied. The stress distribution pattern was analyzed with von Mises stress diagrams. The maximum von Mises stress values ranged from 176 MPa to 263 MPa and varied among the 3D-models. The highest von Mises stress value was found on models with 1-mm-thick composite resin base and 1-mm-thick ceramic inlay. Intermediate values (249-250 MPa) occurred on models with 2-mm-thick composite resin base and 1-mm-thick ceramic inlay and 1-mm-thick composite resin base and 2-mm-thick ceramic inlay. The lowest values were observed on models restored exclusively with ceramic inlay (176 MPa to 182 MPa). It was found that thicker inlays distribute stress more favorably and bases with low elastic modulus increase stress concentrations on the internal surface of the ceramic inlay. The increase of ceramic thickness tends to present more favorable stress distribution, especially when bonded directly onto the cavity without the use of supporting materials. When the use of a composite base is required, composite resin with high elastic modulus and reduced thickness should be preferred.

O objetivo do estudo foi avaliar o efeito da profundidade da cavidade, da espessura da cerâmica e da presença de bases de resina, com os diferentes módulos de elasticidade na distribuição de tensões de von Mises em inlays cerâmicos. Modelos geométricos tridimensionais foram desenvolvidos com o software SolidWorks. As diferenças entre os modelos foram: a profundidade da parede pulpar, a espessura da cerâmica e a presença de bases de resina composta com diferentes espessuras e módulos de elasticidade. Os modelos geométricos foram engastados nas superfícies proximais e base do osso maxilar e uma carga de 100 Newton foi aplicada. O padrão de distribuição de tensões foi analisado com diagramas de tensão de von Mises. O valor de tensão máxima de von Mises foi variável entre os modelos e situou-se na faixa entre 176 e 263 MPa. O maior valor foi encontrado nos modelos restaurados com bases de resina composta de 1 mm e inlay cerâmico de 1 mm de espessura. Valores intermediários (249-250 MPa) ocorreram nos modelos com bases de resina composta de 2 mm e inlays de 1 mm de espessura e nos modelos com bases de resina composta de 1 mm e inlays de 2 mm. Os menores valores foram observados nos modelos restaurados exclusivamente com inlay cerâmico (176-182 MPa). Verificou-se que inlays com maior espessura distribuem o estresse de forma mais favorável e bases com baixo módulo de elasticidade aumentam a concentração de tensões na superfície interna do inlay de cerâmica. O aumento da espessura do material cerâmico tende a apresentar uma distribuição de tensões mais favorável, principalmente quando cimentadas diretamente sobre o preparo cavitário, sem a existência de materiais intermediários. Em situações em que o emprego de materiais de base é necessária, deve-se preferir resinas compostas com alto módulo de elasticidade e espessura reduzida.

Heat Treatment Influences Monomer Conversion and Bond Strength of Indirect Composite Resin Restorations.

PURPOSE: To assess the resin microtensile bond strength (MTBS) and the degree of conversion (DC) of indirect composite resin restorations polymerized with light and heat. MATERIALS AND METHODS: Two direct (Filtek Z100 and Premise) and one indirect (Premise Indirect) composite resins were polymerized with a combination of light and heat (138°C for 20 min). For MTBS, 42 cylinders were fabricated (n = 7). After the surface treatment, cylinders were bonded to each other using adhesive resin (Optibond FL). Specimens were stored in water for 24 h. Another 15 cylinders (n = 5) were fabricated for determining degree of conversion using Fourier Transform Infrared Spectrometry immediately and at 24 h. The MTBS and the DC was submitted to two-way ANOVA. The interaction with existing data was explored with univariate ANOVA and two-way ANOVA. Tukey's HSD post-hoc test was used to detect pairwise differences (α = 0.05). RESULTS: The MTBS to light and heat polymerized Z100 was 75.7 MPa, significantly higher than that to Premise (58.6 MPa) and Premise Indirect (63.9 MPa). The immediate DC for Z100, Premise, and Premise Indirect were 51.0%, 68.7%, and 61.8%, respectively. The DC at 24 h ranged from 53.4% (Z100) to 72.8% (Premise Indirect) and significantly increased for Premise Indirect only. Comparison with previously published data revealed that the heat treatment increased both MTBS and DC of Premise and Premise Indirect. CONCLUSION: Z100 showed better bond strength but lower DC. Heat treatment and a 24-h delay before delivery can benefit DC of Premise Indirect. The increase in DC of Premise and Premise Indirect did not affect their bond strength.

Bond strength and monomer conversion of indirect composite resin restorations, Part 1: Light vs heat polymerization.

PURPOSE: To assess the resin microtensile bond strength (MTBS) and the monomer conversion (MC) of indirect composite resin restorations made of three different materials. MATERIALS AND METHODS: Two light-polymerized direct materials (Filtek Z100 and Premise) and one light- and heat-polymerized indirect material (Premise Indirect) were used. For MTBS testing, 42 cylindrical samples were fabricated (7 pairs per material). Surface conditioning included airborne-particle abrasion, cleaning, and application of a silane. Cylinders were bonded to each other using adhesive resin (Optibond FL). Specimens were stored in water for 24 h. Another 15 cylinders (5 per material) were fabricated for MC measurements (FT-IR) immediately and at 24 h. The MTBS data were submitted to one-way ANOVA and the MC to two-way ANOVA (material and storage time) (α=0.05), followed by post-hoc comparisons with the Tukey test. RESULTS: The MTBS to Z100 was 72.2 MPa, significantly higher than that to Premise (48.4 MPa) and Premise Indirect (52.7 MPa). The immediate MC was similar for all materials (range 51% to 56%) and significantly increased at 24 h (range 57% to 66%), except for Z100. Premise Indirect showed the highest MC (66% at 24 h). CONCLUSION: Z100 showed better "bondability" than Premise and Premise Indirect. Premise Indirect, with its heat initiator, did not present a higher MC.

Efeito do tratamento de superfície e condição de armazenamento sobre a resistência de união resina-cerâmica / Effect of surface treatment and storage condition on the ceramic-resin bond strength

Uma superfície de cada um de quatro blocos foi polida e submetida aos seguintes tratamentos de superfície: bloco A (HF+S) - microjateamento com Al2O3 de 50 μm (15 s), condicionamento com ácido HF a 9,5% (20 s) e aplicação de silano (3 min); bloco B (HF) - microjateamento e condicionamento com ácido HF; bloco C (S) - microjateamento e silano; e bloco D (CJ) - microjateamento com CoJet Sand e aplicação de silano. O adesivo Scotchbond Multi-Purpose Plus foi aplicado sobre a superfície dos blocos A, B e C, e o adesivo Visio-Bond do sistema CoJet, no D, todos polimerizados, e resina composta (Filtek Z250) foi adicionada em quatro incrementos de 1 mm e fotopolimerizada. Os blocos de resina-cerâmica foram, então, seccionados em dois eixos perpendiculares, produzindo cada um aproximadamente 40 corpos de prova, divididos em dois grupos: grupo “Imediato”, dividido em quatro subgrupos: HF+S/I (n = 19), HF/I (n = 19), S/I (n = 20) e CJ/I (n = 16), armazenados por 24 h em água destilada; e grupo “12m+Tc”, dividido em quatro subgrupos: HF+S/12m (n = 20), HF/12m (n = 20), S/12m (n = 20) e CJ/12m (n = 17), armazenados por 12 meses em saliva artificial, seguidos por termociclagem (800 ciclos). Os valores médios obtidos (HF+S/I = 56,85±16,52(a), HF/I = 51,69±11,34(ab), S/I = 50,73±12,37(ab), CJ/I = 40,13±9,27(bc), HF+S/12m = 42,29±17,34(b), HF/12m = 21,03±7,02(d), S/12m = 13,72±6,24(d), CJ/12m = 26,77±21,07(cd)) foram analisados estatisticamente (ANOVA 2). Observou-se interação entre tratamento de superfície e condição de armazenamento. Condicionamento da superfície cerâmica com ácido HF combinado com silanização propiciou maior μ-TBS à resina após 12 meses de armazenamento em saliva artificial e termociclagem...

One surface of each out of four blocks was polished and subjected to the following surface treatments: A: (HF + S) – sandblasting with AL2O3 50 μm (15 s), etching with 9.5% HF (20 s) and silane application (3 min); B:(HF) - sandblasting and etching with HF; C: (S) – sandblasting and silane; D: (CJ) – sandblasting with CoJet Sand and silane application. A three-step total-etch adhesive was applied (ScotchBond Multi-Purpose Plus) on the surface of the blocks A, B, and C, and the light-cured bonding material, proprietary of the CoJet system (Visio-Bond) on block D, light-cured, and composite resin (Filtek Z250) was added in four 1 mm increments and light cured. The ceramic-resin blocks were then sectioned into two perpendicular axes, each producing approximately 40 specimens, divided into two groups: “immediate” group divided into four subgroups: HF + s / i (n = 19) , HF / i (n = 19), S / I (n = 20) and cj / i (n = 16), stored for 24 h in distilled water; and group “12m + tc”, divided into four subgroups: s/12m + HF (n = 20) HF/12m (n = 20) s/12m (n = 20) and CJ/12m (n = 17) stored for 12 months in artificial saliva followed by thermocycling (800 cycles). The obtained average values (HF + s / i = 56.85 ± 16.52 (a) HF / i = 51.69 ± 11.34 (ab) s / i = 50.73 ± 12.37 (ab), CJ/ i = 40.13 ± 9.27 (bc) + HF s/12m = 42.29 ± 17.34 (b), HF/12m = 21.03 ± 7.02 (d), s / 12m = 13.72 ± 6.24 (d), 26.77 ± 21.07 CJ/12m = (cd)) were statistically analyzed (2-way ANOVA). Interaction between surface treatment and storage conditions were observed. Conditioning of the ceramic surface with HF associated with silanization provided greater μ-TBS values to resin after 12 months of storage in artificial saliva and thermocycling...

Silorane adhesive system: a case report.

Silorane-based composite resin requires a specific adhesive system: a 2-step self-etching adhesive. Clinical protocols are well established and are based on the principles of adhesion to mineralized dental tissues. In this paper, we present a clinical application of the silorane adhesive system in a class-II restoration using silorane-based composite resin.

Influence of reused dental burs on bond strength to dentin

AIM: this study evaluated the bond strength of an adhesive system to human dentin prepared with reused diamond burs. MATERIAL AND METHODS: five molars (G1) were prepared in a standardized way with five diamond burs. Flat deep dentin surfaces were etched, received adhesive and received composite build-ups. The same burs were cleaned and reused on another five teeth groups (G2 until G8). After 24-hours storage and thermocycling, 50 dentin-resin sticks per group were obtained and subjected to microtensile bond strength test (µTBS). RESULTS: analysis of variance (ANOVA) and Tukey test were applied to identify differences between groups (p<0.05). The reuse of a diamond bur for more than two preparations resulted in significantly lower µTBS values (G1 = G2 > G3 = G4 = G5 = G6 = G7 = G8). CONCLUSION: Reuse of diamond burs interfered on adhesion between dentin and resin.

Avaliação clínica de um sistema adesivo autocondicionante com e sem condicionamento ácido prévio do esmalte em lesões cervicais não cariosas / Clinical evaluation of a self-etch adhesive system with and without previous acid conditioned of the enamel on non carious cervical lesions

Objetivo: O objetivo deste estudo foi comparar o desempenho clínico de lesões cervicais não cariosas (LCNCs) restauradas com o sistema adesivo autocondicionante com e sem condicionamento prévio do esmalte, pelo período de 12 meses. Metodologia: Sessenta restaurações foram realizadas e distribuídas em dois grupos constituídos de 30 restaurações cada da seguinte maneira: Grupo Adh: as LCNCs foram restauradas com o sistema adesivo autocondicionante de acordo com as instruções do fabricante; Grupo CAdh: as margens de esmalte das LCNCs foram condicionadas com ácido fosfórico a 37% previamente a aplicação do sistema adesivo autocondicionante. Todas as restaurações foram avaliadas pelo método direto USPHS modificado. Para o tratamento estatístico dos dados, foi utilizado o teste da Razão de Verossimilhança, com nível de significância de 5% (p<0,05)

Influência do uso do selante de superfície na microinfiltração e no manchamento de restaurações de resina composta / Influence of surface sealant on microleakage and staining of composite resin restorations

Este trabalho teve como objetivo avaliar a infiltração marginal e o manchamento de restaurações de resinas após o resselamento. Foram confeccionadas 40 cavidades classe V em 20 terceiros molares. Após o procedimento restaurador, os dentes foram divididos aleatoriamente em quatro grupos: ISS (acabamento e polimento imediato), ICS (acabamento e polimento imediato e resselamento com o selante de superfície Biscover); 24hSS (acabamento e polimento 24 horas após o término da restauração) e 24hCS (acabamento e polimento 24 horas após o término da restauração e resselamento com o selante de superfície Biscover). Os grupos foram termociclados, imersos em fucsina básica 0,5%, fotografados para estimar o grau de manchamento por meio de escores e analisados pelo teste Kruskall Wallis. Os espécimes foram incluídos em resina epóxica, seccionados, fotografados, mensurados pelo software Image Tool e passaram por análise de variância (ANOVA). Como resultado, a variável resselamento apresentou infiltração marginal e manchamento superficial para todos os grupos, entretanto diminuiu a microinfiltração marginal. Com isto, conclui-se que o momento de acabamento não interferiu na microinfiltração.O resselamento reduziu a microinfiltração marginal e esse procedimento potencializou o manchamento das restaurações de resinas compostas.