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AIM: This study was undertaken to examine the effect of root canal (RT) sealers content and the cleaning procedure of RT walls on bond strength (BS) of a fiber reinforced composite (FRC) post cemented with resin-based or zinc phosphate cement. MATERIALS AND METHODS: Forty bovine roots were divided into 2 groups (n = 20) and obturated with gutta-percha points plus Sealer 26 sealer or gutta-percha points plus N-Rickert sealer. In each group, half (n = 10) of intracanal walls was cleaned with ethanol and the other half with sulfuric ether. In each of these subgroups, half of intracanal posts (n = 5) were cemented with Bistite resin-based cement and half with zinc phosphate cement. Specimens were submitted to pull-out test and tensile force until post dislodgement. The maximum forces required for post removal was expressed in MPa, means were submitted to statistical analysis (Analysis of Variance Test, a = 0.05). RESULTS: Fiber reinforced composite cemented with zinc phosphate were significantly more retentive than those cemented with Bistite (p < 0.05). Regarding the influence of eugenol-based sealer on post retention, there was a statistically significant difference (p < 0.05) only between groups cemented with Bistite, in which canals filled with N-Rickert + gutta-percha showed lower BS than canals filled with Sealer 26 + gutta-percha. CONCLUSION: Despite endodontic cement used, higher pull-out bond strength were obtained when posts were cemented with zinc phosphate. CLINICAL SIGNIFICANCE: The importance of ethanol or sulphuric ether application to properly replace water from intraradicular dentine still requires further investigations, especially to clarify if this technique may reduce the effect of aging and improve the stability of the bond, when used to cement fiber posts into the root canal.

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A radiopacidade é um pré-requisito imprescindível para materiais utilizados como base eforramento de restaurações. Possibilita que o profissional identifique a presença do material,permitindo a diferenciação com a estrutura dental adjacente. Objetivo: O objetivo desse estudofoi avaliar a radiopacidade de materiais de base e forramento disponíveis para uso clínico ecomparar com a radiopacidade do esmalte e dentina. Materiais e Métodos: Foram analisados:13 marcas comerciais de cimento de ionômero de vidro, 1 amálgama e 1 resina composta. Foramconfeccionados três corpos de prova com espessura de 1 mm para cada cimento de ionômerode vidro e para cada material restaurador. Obteve-se 1 espécime, com 1 mm de espessura, deesmalte/dentina através de um corte transversal da coroa dental. As tomadas radiográficas foramfeitas com o sistema digital ~VG 5000 Kodak e tempo de exposição de 0,32 segundos. Asimagens obtidas foram trabalhadas no programa Image Tool® obtendo-se os valores médiosde cinza. A análise estatística ANOVA, seguida pelo teste de Tukey (p 0,05) detectou diferençasconsideráveis. Resultados: Alguns cimentos de ionômero de vidro apresentaram radiopacidadeinferior à da dentina e inadequada segundo as normas ISO9917, sendo considerada insuficientepara um correto diagnóstico radiográfico. Conclusão: Conclui-se que existem cimentos de ionômerode vidro indicados como base e forramento de restaurações disponíveis para aquisiçãocom radiopacidade imprópria para serem detectados radiograficamente.

The radiopacity is an essential prerequisite for materiais used as a base liner and restorationsand allows the professional to identify the presence of the material allowing the differentiationfrom the adjacent tooth structure. Objectives: The aim of this study was to evaluate the radiopacityof base and liner materiais available for clinical use and compare to the radiopacity ofenamel and dentin. Materiais and methods: 13 glass ionomer cements, one resin composite andone amalgam were evaluated. Three specimens with 1 mm thickeness for each glass ionomercement and restorative material were prepared. Cross section was made from a third molardental crown to obtain enamel and dentin specimen with thickness of 1 mm. Radiographswere taken with digital system Kodak RVG5000 and exposure time of 0.32 seconds. The imageswere analysed through the programe Image Tool" to obtain the mean grey values. Statisticaltest ANOVA followed by Tukey test (p<0.05) detected considerable differences. Results: Someglass ionomer cements presented radiopacity lower than dentin, considered insufficient for acorrect radiographic diagnosis, according to ISO 9917. Conclusion: It was concluded that somebase and liner materiais available for purchase have an inadequaderadiopacity to be detectedradiographically.

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BACKGROUND: The use of laser irradiation for dental surface treatment may increase tooth-composite bond strength. Its use on bleached teeth may decrease the waiting time between bleaching and restorative procedures. OBJECTIVE: This study aimed to evaluate the bond strength between a composite resin and bovine enamel bleached with 35% hydrogen peroxide and etched with Er:YAG laser. MATERIALS AND METHODS: Thirty bovine teeth were randomly divided into six groups (n = 5): G1, unbleached and restored 24 h after storage in artificial saliva, etching with 35% phosphoric acid (PA) (control); G2, unbleached and restored 24 h after storage in artificial saliva, etching with Er:YAG laser and 35% PA; G3, bleached and restored immediately afterward, etching with 35% PA; G4, bleached and restored 24 h after bleaching, etching with 35% PA; G5, bleached and restored immediately afterward, etching with Er:YAG and 35% PA laser; G6, bleached and restored 24 h after bleaching, etching with Er:YAG laser and 35% PA. Bond strength was quantitatively evaluated by microtensile test (1.0 mm/min). Data were submitted to statistical analysis using ANOVA and Tukey tests (α = 0.05). RESULTS: Bond strength values (MPa) were G1, 26.17 ± 4.44; G2, 28.87 ± 3.94; G3, 17.25 ± 4.58; G4, 21.93 ± 5.02; G5, 16.69 ± 2.31; and G6, 29.06 ± 8.31. There was no statistically significant difference among groups G1, G2, and G6 (p = 0.119), which presented higher bond strength than group G4, followed by groups G3 and G5. CONCLUSION: Er:YAG irradiation of bleached surfaces may favor bonding procedures when performed 24 h after bleaching.

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PURPOSE: To assess the effects of three different dental adhesive systems on the formation of secondary root caries, in vitro, with a standardized interfacial gap in a filled cavity model. METHODS: 40 sound human molars were selected and randomly assigned to four experimental groups: Clearfil SE Bond (CSEB), Xeno III (X-III), Scotchbond Multi-Purpose Plus (SBMP) and negative control (NC) without an adhesive system. After the standardized Class V cavity preparations on the buccal and lingual surfaces, restorations were placed with resin composite (Filtek Z250) using a standardized interfacial gap, using a 3 x 2 mm piece of 50 microm metal matrix. The teeth were sterilized with gamma irradiation and exposed to a cariogenic challenge using a bacterial system with Streptococcus mutans. Depth and extension of wall lesions formed and the depth of outer lesions were measured by software coupled with light microscopy. RESULTS: For wall lesion extension the ANOVA test showed differences between groups except between X-III and SBMP (P=0.294). The Tukey's test of confidence intervals indicated smaller values for the CSEB group than for the others. For wall lesion depth the CSEB group also presented the smallest mean values of wall lesion depth when compared to the others (P<0.0001) for all comparisons using Tukey's test. Regarding outer lesion depth, all adhesives showed statistically similar behavior. SEM evaluation of the morphologic appearance of caries lesions confirmed the statistical results showing small caries lesion development for cavities restored with CSEB adhesive system, which may suggest that this adhesive system interdiffusion zone promoted a good interaction with subjacent dentin protecting the dental tissues from recurrent caries.

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PURPOSE: To evaluate the influence of cleaning procedures (pumice, anionic detergent and both procedures together) on the tensile bond strength of etch-and-rinse and self-etch adhesive systems to bovine enamel and dentin in vitro. METHODS: Eighty non-carious, bovine incisors were extracted, embedded in acrylic resin to obtain enamel/dentin specimens. Flat bonding surfaces were obtained by grinding. Groups were divided according to substrate (enamel or dentin), adhesive system [etch-and-rinse, Adper Single Bond 2 (SB) or self-etch, Clearfil Protect Bond (PB)]; and cleaning substances (pumice, anionic detergent and their combination). The teeth were randomly divided into 20 groups (n=8): G1--Enamel (E) + SB; G2--E + oil (O) + SB; G3--E + O + Pumice (P) + SB; G4--E + O + Tergentol (T) + SB; G5--E + O + P + T + SB; G6--E + PB; G7--E + O + PB; G8--E + O + P + PB; G9--E + O + T + PB; G10--E + O + P + T + PB; G11--Dentin (D) + SB; G12 D + SB + O; G13--D + SB + O + P; G14--D + SB + O + T;G15--D + SB + O + P + T; G16--D + PB; G17--D + O + PB +; G18--D + O + P + PB; G19--D + O + T + PB; G20--D + O + P + T + PB. Specimens were contaminated with handpiece oil for 5 seconds before bonding. Adhesive systems and resin composite were applied according to manufacturers' instructions. Specimens were tested in tension after 24 hours of immersion using a universal testing machine at a crosshead speed of 0.5 mm/minute. Bond strengths were analyzed with ANOVA. Failure sites were observed and recorded. RESULTS: Tensile bond strength in MPa were: G1 (23.6 +/- 0.9); G2 (17.3 +/- 2.2); G3 (20.9 +/- 0.9); G4 (20.6 +/- 0.5); G5 (18.7 +/- 2.3); G6 (23.0 +/- 1.0); G7 (21.5 +/- 2.4); G8 (19.9 +/- 1.3); G9 (22.1 +/- 1.2); G10 (19.1 +/- 1.2); G11 (18.8 +/- 1.3); G12 (15.7 +/- 2.1); G13 (17.8 +/- 3.3); G14 (15.3 +/- 2.9); G15 (15.6 +/- 1.9); G16 (14.7 +/- 2.3); G17 (5.5 +/- 0.9); G18 (19.3 +/- 1.8); G19 (15.6 +/- 1.6); G20 (20.3 +/- 3.9). Statistical analysis showed that the main factors substrate and cleaning were statistically significant, as well as the triple interaction between factors of variance. However, the factor adhesive system did not show statistical difference. Oil contamination reduced bond strengths, being less detrimental to enamel than to dentin. Etch-and-rinse (SB) and two-step self-etch (PB) systems had similar bond strengths in the presence of oil contamination. For etch-and-rinse (SB), the cleaning procedures were able to clean enamel, but dentin was better cleaned by pumice. When self-etch (PB) system was used on enamel, anionic detergent was the best cleaning substance, while on dentin the tested procedures were similarly efficient.

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The cleaning of cavity walls aims to improve adhesive restorative procedures and longevity of restorations. This study has compared the effect of three cleaning agents--sodium bicarbonate jet (Profi II, Dabi Atlante, São Paulo, Brazil); pumice paste plus a biologic detergent (Tergestesim, Probem, São Paulo, Brazil); air water spray--on the bond strength between dentin and two different adhesive systems: Clearfil SE Bond (Kuraray, Kioto, Japan) and Scotchbond Multi-Purpose Plus (3M-ESPE, São Paulo, Brazil). Six groups (n: 10) of dental fragments obtained from young adult extracted teeth were prepared, and each one received one of the listed surface cleaning techniques. After the adhesive application, a cone-shaped test body was built with AP-X (Kuraray, Kioto, Japan) or Z100 (3M-ESPE, São Paulo, Brazil) composite resins, using a Teflon matrix. The specimens were tested for tensile bond strength after one-week storage in distilled water at 37 degrees C. Two pairs of fractured specimens of each group were randomly chosen and processed for scanning electron microscopy (SEM) analysis. ANOVA test of the bond strength values showed no statistical differences among the cleaning agents and neither between their interactions with the bonding systems. Upon SEM analysis, most surfaces showed mixed fractures of adhesive and cohesive failures in bonding resin to dentin. Based on statistical and SEM analysis, it was concluded that the cleaning agents studied did not interfere with the bond strength of the adhesive systems used to dentin.

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OBJECTIVES: The aim of this study was to compare the interaction of dentin with 2 different self-etch resin bonding systems, as well as with a total-etch resin bonding system. METHOD AND MATERIALS: Nine recently extracted, unerupted third molars, roots, and occlusal thirds were used. A standardized smear layer was produced on the occlusal dentin surface exposed. The specimens were split into 3 groups of 3 specimens each, 1 group for each bonding agent: Clearfil Liner Bond 2, Prime & Bond 2.1, and Scotchbond Multipurpose (control group). After the tooth was briefly sprayed with an air/water mixture, 1 of the experimental adhesive systems was applied on the dentin surface. A 2-mm layer of composite was applied over the adhesive system layer. After 7 days in distilled water at 37 degrees C, the specimens were cross-sectioned perpendicular to the resin-dentin interface. The crosssections were mounted on aluminum stubs, etched with 2% hydrochloridric acid, and studied using scanning electron microscopy. A descriptive analysis of the images of the interdiffusion zone characteristics was done first. Afterwards, statistical analyses of the measurements of the interdiffusion zone structures-hybrid layer thickness, resin tags penetration, and adhesive layer thickness using analysis of variance, followed by "post hoc" test-were carried out to compare the bonding systems' interactions. RESULTS: The descriptive analysis of the self-etch bonding systems studied showed a good interlocking of Clearfil Liner Bond 2 with dentin, similar to Scotchbond Multipurpose and better than Prime & Bond 2.1. The analysis of variance, followed by the "post hoc" test, identified statistical differences just for the adhesive layer thickness that was thicker for Scotchbond than for Prime & Bond (P = .020). The "post hoc" test also showed a strong tendency to identify differences between the Scotchbond and the Prime & Bond groups (P = .062), and the Clearfil and the Prime & Bond groups (P = .069). CONCLUSION: Within the limitations of this study, Clearfil Liner Bond 2 produced the thickest hybrid layer with deepest tag formation and good interlocking with dentin, similar to the control. Statistical differences among the interdiffusion zone of the 3 bonding systems studied were identified just for the adhesive layer thickness, which was thicker for Scotchbond than for Prime & Bond.

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Introdução - O dente humano apresenta fluorescência quando irradiado por luz ultravioleta. Para a obtenção da estética com restaurações diretas de resina composta é necessário que este material se assemelhe ao dente em diferentes situações, inclusive quando submetido à incidência de diversos tipos de luz. Métodos - Nesta pesquisa, avalia-se a emissão de fluorescência de algumas marcas comerciais de resina composta anterior/posterior quando submetidas apenas à iluminação por lâmpadas emissoras de radiação ultravioleta. Dez avaliadores calibrados classificaram em níveis de fluorescência (alta, média e baixa) os 33 corpos de prova, dispostos aleatoriamente em um ambiente escuro desprovido de luz natural e apenas sob o efeito da luz ultravio1eta. Resultados - Devido à amostra obtida não ser normal nem homogênea, os escores conferidos pelos avaliadores foram submetidos ao Teste de Friedman. A distribuição das diversas marcas comerciais entre 11 grupos permitiu identificar o comportamento de cada amostra. Conclusões - Houve uma grande diferença entre as vârias marcas comerciais de resinas compostas que foram identificadas como de alta, média e baixa fluorescência. Geralmente as marcas comerciais de cada fabricante apresentavam valores de fluorescência semelhantes. As resinas compostas de uma mesma marca comercial, indicadas para reproduzir a dentina, o esmalte ou a borda incisal apresentaram fluorescências iguais.

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Introdução - É importante conhecer o valor da adesão entre porcelana e dentina humana devido à variedade de agentes cimentantes e adesivos existentes. Métodos - Foi avaliada in vitro a força de união por tração entre a porcelana feldspática Noritake Super Porcelain EX-3 (Noritake) e a dentina humana profunda. Noventa e seis corpos de prova de porcelana com 2 mm de altura e 5 mm de diâmetro foram jateados, condicionados com ácido t1uorídrico e submetidos à aplicação de silano. As superfícies de porcelana foram, então, cimentadas à dentina profunda de molares humanos. Para essa cimentação, foram utilizados: Panavia 21 (Kuraray) associado ao ED Primer (Kuraray) ou ao Bond-l (Jeneric/Pentron) fotoativado; Cement-it (Jeneric/Pentron), associado ao Bond-l fotoativado ou não; Variolink (Vivadent), associado ao Syntac Primer/Adhesive (Vivadent) fotoativado ou não; Nexus (Kerr) associado ao Nexus n.1+ n.2+ n.3 (Kerr) ou ao Bond-l fotoativado. Os testes de resistência à tração foram realizados 20 minutos e 24 horas após a cimentação. Resultados e Conclusões - Os resultados obtidos foram submetidos à análise estatística. Conclui-se que a resistência adesiva à tração entre a porcelana feldspática e a dentina humana profunda é: 1) semelhante, após 20 minutos e após 24 horas; 2) semelhante para os quatro tipos de cimentos resinosos avaliados, quando não for realizada a foto ativação do adesivo antes da cimentação; 3) maior, quando os adesivos forem fotoativados antes da cimentação (exceto com o Panavia 21). Os resultados ainda sugerem que a técnica adesiva empregada é mais importante que o tipo de cimento resinoso utilizado.

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Introdução - Avaliação, in vitro, da adesão de restaurações diretas de resina composta às superfícies dentinárias previamente tratadas com dois agentes dessensibilizantes: Gluma Desensitizer, Health-Dent Desensitizer; e um desinfetante cavitário: Cav-Clean. Métodos - As coroas de 20 molares humanos extraídos foram seccionadas paralelas ao plano oclusal de modo a expor a dentina, que foi polida até a granulação 600. A seguir foram realizados o condicionamento com ácido fosfórico a 37% por 15 segundos e lavagem por 30 segundos. As amostras foram divididas em quatro grupos para sofrerem diferentes tratamentos: Grupo 1 (controle): adesivo dentário (Single Bond) + resina composta (Z100); Grupo 2: Gluma + adesivo dentário + resina composta; Grupo 3: Health-Dent + adesivo dentário + resina composta; Grupo 4: Cav-Clean + adesivo dentário + resina composta. Os produtos testados foram aplicados sobre a dentina segundo as instruções do fabricante. Após o armazenamento por 24 horas, as amostras foram tracionadas na máquina Instron 4442, e os dados obtidos foram analisados através do teste t de Student com p=0,05. Resultados - Não houve diferenças significativas na força de adesão entre os grupos analisados quando comparados com o grupo controle e entre si. Conclusão - O uso de dois agentes dessensibilizantes e um desinfetante cavitário antes da aplicação do uso do adesivo dentário e da resina composta não imterfere com a força da adesão final

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