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

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

AIM: To evaluate the bonding durability of materials used as sealants on different dentitions. METHODS: Deciduous (D) and permanent (P) molars were divided into four groups (n=5) and sealed with Fluroshield (F) and OptiBond FL (FL). Blocks of composite resin were built, stored in distilled water (24 h/37 °C), sectioned into 0.8 mm2 and tested at tensile (0.5 mm/min) after 24 h and 6 months. The fractures were observed and classified into adhesive, cohesive or mixed types. The data were analyzed using repeated measures ANOVA and Tukey test (α=5%), with tooth as the experimental unit. RESULTS: There were differences for dentition (p=0.0097), dental sealant (p=0.0019) and time (p=0.0001). At 24h the highest bond strength was observed for OptiBond FL on deciduous and permanent teeth, similar to Fluroshield at both dentitions. After 6 months the bond strength of OptiBond FL did not decrease in the permanent teeth, but decreased similar to Fluroshield in deciduous teeth, the bond strength of Fluroshield decreased similarly in both dentitions. CONCLUSIONS: The bond strength of dental sealants varied with the experimental conditions.

OBJETIVO: comparar a resistência ao atrito entre braquetes autoligáveis e braquetes convencionais, variando o tipo de fio. MÉTODOS: foram usados braquetes incisivos Abzil Kirium Capelozza e Easy Clip. Uma ligadura elastomérica ou um fio ligável de 0,010" foi usado para ligação do fio no braquete Abzil. Três tipos de ligas de fio ortodôntico foram avaliadas: fio de NiTi de 0,016"; fio de NiTi de 0,016" x 0,022"; e fio de aço de 0,019" x 0,025". Dez observações foram feitas para cada combinação "braquete-fio-inclinação". Os braquetes foram montados em um aparelho especial, posicionados a 90° em relação ao fio, e testados em duas inclinações. O teste de atrito foi realizado na máquina universal de ensaios, a 5mm/min e com 10mm de deslocamento. As médias (em MPa) foram submetidas aos testes ANOVA e de Tukey, a 5% de significância. As superfícies dos fios e dos braquetes foram observadas no MEV. RESULTADOS: o braquete com amarrilhos metálicos (16,48 ± 8,31MPa) apresentou médias mais altas que o braquete com ligaduras elastoméricas (4,29 ± 2,16MPa) e o braquete autoligável (1,66 ± 1,57) (p < 0,05), os quais também diferiram entre si (p < 0,05). Quanto ao tipo do fio, o fio de aço de 0,019" x 0,025" (5,67 ± 3,97MPa) apresentou médias mais baixas (p < 0,05) que os fios de NiTi de 0,016" (8,26 ± 10,92MPa) e de 0,016" x 0,022" (8,51 ± 7,95), os quais não diferiram entre si (p > 0,05). Nenhuma diferença estatística (p > 0,05) foi encontrada entre inclinações de zero (7,76 ± 8,46) e cinco (7,19 ± 7,93) graus. Concluão: o atrito foi influenciado pelo tipo de braquete e sistemas de ligaduras. Diferentes aspectos morfológicos foram observados para os braquetes e fios estudados.

OBJECTIVE: To compare the frictional resistance between self-ligating and conventional brackets tied to different types of wire. MATERIAL AND METHODS : Abzil Kirium Capelozza (Pattern I) and Easy Clip (Roth prescription) incisor brackets were used. An elastomeric ligature or a ligating wire 0.10-in was used to ligate the wire to the Abzil bracket. Three types of orthodontic archwire alloys were assessed: 0.016-in NiTi wire, 0.016 x 0.021-in NiTi wire and 0.019 x 0.025-in steel wire. Ten observations were carried out for each bracket-archwire angulation combination. Brackets were mounted in a special appliance, positioned at 90 degrees in relation to the wire and tested in two angulations. Frictional test was performed in a Universal Testing Machine at 5 mm/min and 10 mm of displacement. The means (MPa) were submitted to ANOVA and Tukey's test set at 5% of significance. The surfaces of wires and brackets were observed at SEM. RESULTS: Steel-tied brackets (16.48 ± 8.31) showed higher means of frictional resistance than elastomeric-tied brackets (4.29 ± 2.16 ) and self-ligating brackets (1.66 ± 1.57) (P < 0.05), which also differed from each other (P < 0.05). As for the type of wire, 0.019 x 0.025-in steel wire (5.67 ± 3.97) showed lower means (P < 0.05) than 0.16-in NiTi wire (8.26 ± 10.92) and 0.016 x 0.021-in NiTi wire (8.51 ± 7.95), which did not differ from each other (P > 0.05). No statistical differences (P > 0.05) were found between zero (7.76 ± 8.46) and five-degree (7.19 ± 7.93) angulations. CONCLUSIONS: Friction was influenced not only by the type of bracket, but also by the ligating systems. Different morphological aspects were observed for the brackets and wires studied

Objectives: This study evaluated the influence of different exposure times to saliva in situ in comparison with an antioxidant treatment on composite resin bond strength to human enamel restored after tooth bleaching. Material and Methods: Forty human teeth specimens measuring 5x5 mm were prepared and randomly allocated into 5 groups with 8 specimens each: Gct (control group, restored on unbleached enamel); Gbl (restored immediately after bleaching); Gsa (bleached, treated with 10% sodium ascorbate gel for 60 min and restored); G7d (bleached, exposed to saliva in situ for 7 days and restored); and G14d (bleached, exposed to saliva in situ for 14 days and restored). Restored samples were cut into 0.8 mm2 sticks that were tested in microtensile. Specimens were microscopically analyzed and failure modes were classified as adhesive, cohesive, or mixed. Pretest and cohesive failures were not considered in the statistical analysis, which was performed with one-way ANOVA and Tukey's post-hoc test (α=0.05), with the dental specimen considered as the experimental unit. Results: Mean bond strength results found for Gbl in comparison with Gct indicated that bleaching significantly reduced enamel adhesiveness (P<0.01). However, no statistically significant differences were found between Gct, Gsa and G7d (P>0.05). Bond strength found for G14d was significantly higher than for Gsa (P<0.01). Fractures modes were predominantly of a mixed type. Conclusions: Bonding strength to bleached enamel was immediately restored with the application of sodium ascorbate and exposure to human saliva in situ for at least 7 days. Best results were obtained with exposure to human saliva in situ for 14 days. Treatment with sodium ascorbate gel for 60 min may be recommended in cases patients cannot wait for at least 7 days for adhesive techniques to be performed.

Objectives This study aimed to compare the micro-tensile bond strength of methacrylate resin systems to a silorane-based restorative system on dentin after 24 hours and six months water storage. Material and Methods The restorative systems Adper Single Bond 2/Filtek Z350 (ASB), Clearfil SE Bond/Z350 (CF), Adper SE Plus/Z350 (ASEP) and P90 Adhesive System/Filtek P90 (P90) were applied on flat dentin surfaces of 20 third molars (n=5). The restored teeth were sectioned perpendicularly to the bonding interface to obtain sticks (0.8 mm2) to be tested after 24 hours (24 h) and 6 months (6 m) of water storage, in a universal testing machine at 0.5 mm/min. The data was analyzed via two-way Analysis of Variance/Bonferroni post hoc tests at 5% global significance. Results Overall outcomes did not indicate a statistical difference for the resin systems (p=0.26) nor time (p=0.62). No interaction between material × time was detected (p=0.28). Mean standard-deviation in MPa at 24 h and 6 m were: ASB 31.38 (4.53) and 30.06 (1.95), CF 34.26 (3.47) and 32.75 (4.18), ASEP 29.54 (4.14) and 33.47 (2.47), P90 30.27 (2.03) and 31.34 (2.19). Conclusions The silorane-based system showed a similar performance to methacrylate-based materials on dentin. All systems were stable in terms of bond strength up to 6 month of water storage.

Este estudo avaliou a efetividade de diferentes selantes aplicados a uma resina nanoparticulada. Quarenta espécimes de Filtek Z-350 foram obtidos depois da inserção do material em um molde de aço inoxidável seguido por fotoativação por 20 s. Os grupos foram divididos (n=10) de acordo com o tratamento superficial aplicado: Grupo controle (sem tratamento superficial), Fortify, Fortify Plus ou Biscover LV. Os espécimes foram submetidos a escovação simulada usando uma carga de 200 g e 250 ciclos/min para simular 1 semana, 1, 3 e 6 meses e 1 e 3 anos, considerando que 10.000 ciclos equivalem a um ano de escovação. Escovas Oral-B de cabeça macia e dentifrício Colgate Total diluído a 1:2 em água foram utilizados. Depois de cada período de simulação, a rugosidade superficial foi medida em triplicata. Os dados foram submetidos à ANOVA de dois fatores e ao teste de Tukey com nível de 95% de confiança. Os espécimes foram observados em microscopia eletrônica de varredura (MEV) depois de cada ciclo de escovação. O grupo controle não foi diferente (p>0,05) que os outros grupos, exceto pelo Fortify Plus (p<0,05), que foi mais rugoso. Nenhuma diferença (p>0,05) foi observada em 1 mês de simulação entre os grupos experimentais e o controle. Fortify e Fortify Plus apresentaram rugosidade regular com o tempo, diferindo da inicial em todos os tempos. Nenhum dos grupos selados mostrou melhor desempenho (p>0,05) que o grupo controle em qualquer um dos tempos. MEV ressaltou as diferenças encontradas durante o teste de rugosidade. Selantes de penetração de superfície não melhoram a rugosidade da resina nanoparticulada.

This study evaluated the effectiveness of different sealants applied to a nanofiller composite resin. Forty specimens of Filtek Z-350 were obtained after inserting the material in a 6x3 mm stainless steel mold followed by light activation for 20 s. The groups were divided (n=10) according to the surface treatment applied: Control group (no surface treatment), Fortify, Fortify Plus and Biscover LV. The specimens were subjected to simulated toothbrushing using a 200 g load and 250 strokes/min to simulate 1 week, 1, 3 and 6 months and 1 and 3 years in the mouth, considering 10,000 cycles equivalent to 1 year of toothbrushing. Oral-B soft-bristle-tip toothbrush heads and Colgate Total dentifrice at a 1:2 water-dilution were used. After each simulated time, surface roughness was assessed in random triplicate readings. The data were submitted to two-way ANOVA and Tukey's test at a 95% confidence level. The specimens were observed under scanning electron microscopy (SEM) after each toothbrushing cycle. The control group was not significantly different (p>0.05) from the other groups, except for Fortify Plus (p<0.05), which was rougher. No significant differences (p>0.05) were observed at the 1-month assessment between the experimental and control groups. Fortify and Fortify Plus presented a rougher surface over time, differing from the baseline (p<0.05). Biscover LV did not differ (p>0.05) from the baseline at any time. None of the experimental groups showed a significantly better performance (p>0.05) than the control group at any time. SEM confirmed the differences found during the roughness testing. Surface penetrating sealants did not improve the roughness of nanofiller composite resin.

Silorane-based composite, an epoxy material, was marketed as promising less polymerization contraction than conventional restorative materials. The aim of this study was to evaluate, by means of photoelasticity, the polymerization stress generated by a silorane-based composite. Thirty photoelastic rings with orifices measuring 5 mm (d) × 3 mm (h) were prepared and divided into 6 groups (n = 5) according to the material tested. The inside walls of the rings were sandblasted with aluminum oxide, after which the restorative materials were inserted into the orifices and photoactivated according to the manufacturer's instructions. The specimens were analyzed and the visual representation of the stress was measured considering the isochromatic ring of first order. The data were converted to MPa and subjected to ANOVA and Tukey's test (α= 0.05). The adhesive Filtek P-90 (G5) showed high contraction stress (p < 0.05) when compared to G1, G2, G3, G4, and G6, which did not differ from each other (p > 0.05). The composite Filtek P-90 showed similar contraction stress compared to the conventional composite and, additionally, its adhesive showed higher stress than did the etch-and-rinse 2-step adhesive.

O objetivo deste estudo foi avaliar a resistência de união (RU) de adesivos autocondicionantes com e sem HEMA à dentina. A superfície oclusal de 20 terceiros molares foi removida e a dentina abrasionada com lixa de carbeto de silício de granulação 600. Em seguida, os dentes foram divididos aleatoriamente em 4 grupos (n=5) e restaurados com os sistemas adesivos Go, Adper SE Plus, OptiBond All-In-One ed Clearfil 3S Bond e resina composta Filtek Z350. Após fotoativação (600 mW/cm²), eles foram armazenados em água destilada (37ºC/24 h) e secionados nas direções mésio-distal e vestíbulo-lingual, para obter corpos-de-prova em formato de palito (0,8 mm²). Os palitos foram tracionados em máquina de ensaio universal com velocidade de 0,5 mm/min, e os modos de fratura observados em microscópio eletrônico de varredura e classificados em adesiva, coesiva ou mista. Os dados de RU (em MPa) foram analisados estatisticamente por ANOVA a um critério e teste de Tukey com nível de significância de 5%. A menor RU foi observada para o adesivo GO (10,57 ± 3,72) (p=0,001). Adper SE Plus (29,08 ± 8,93), OptiBond All-In-One (28,36 ± 6,49) e Clearfil 3S Bond (28,62 ± 6,97) foram estatisticamente semelhantes entre si (p>0.05). Fraturas mistas predominaram nos grupos. Concluiu-se que a influência do HEMA na RU foi material-dependente.

This study analyzed the bond strength (BS) of HEMA versus HEMA-free self-etch adhesive systems to dentin. The occlusal surface of 20 third molars was removed and the dentin was abraded with 600-grit silicon carbide paper. The teeth were randomly assigned to 4 groups (n=5) and restored with GO, Adper SE Plus, OptiBond All-In-One, and Clearfil 3S Bond adhesive systems and Filtek Z350 composite. After light curing (600 mW/cm²), the teeth were stored in distilled water at 37ºC for 24 h and were sectioned in the mesiodistal and buccolingual directions to obtain sticks (0.8 mm²). The sticks were subjected to tensile force using a universal testing machine (0.5 mm/min), and the modes of failure were analyzed by scanning electron microscopy and classified as adhesive, cohesive, or mixed. The BS data (in MPa) were treated using one-way ANOVA and Tukey’s tests at 5% significance. GO presented the lowest mean bond strength value (10.57 ± 3.72) and differed significantly from the other materials (p=0.001), which, in turn, presented statistically similar results (p>0.05) among themselves: Adper SE Plus (29.08 ± 8.93), OptiBond All-In-One (28.36 ± 6.49), and Clearfil 3S Bond (28.62 ± 6.97). Mixed fractures were the most prevalent. It was concluded that the influence of HEMA on BS to dentin was material dependent.

OBJECTIVES: The aims of this study were to evaluate the effect of resin composite (Filtek Z250 and Filtek Flow Z350) and adhesive system [(Solobond Plus, Futurabond NR (VOCO) and Adper Single Bond (3M ESPE)] on the microtensile (μTBS) and microshear bond strength (μSBS) tests on enamel, and to correlate the bond strength means between them. MATERIAL AND METHODS: Thirty-six extracted human molars were sectioned to obtain two tooth halves: one for μTBS and the other one for μSBS. Adhesive systems and resin composites were applied to the enamel ground surfaces and light-cured. After storage (37(0)C/24 h) specimens were stressed (0.5 mm/min). Fracture modes were analyzed under scanning electron microscopy. The data were analyzed using two-way ANOVA and Tukey's test (α=0.05). RESULTS: The correlation between tests was estimated with Pearson's product-moment correlation statistics (α =0.05). For both tests only the main factor resin composite was statistically significant (p<0.05). The correlation test detected a positive (r=0.91) and significant (p=0.01) correlation between the tests. CONCLUSIONS: The results were more influenced by the resin type than by the adhesives. Both microbond tests seem to be positive and linearly correlated and can therefore lead to similar conclusions.

OBJECTIVES: To assess the bond strength and the morphology of enamel after application of self-etching adhesive systems with different acidities. The tested hypothesis was that the performance of the self-etching adhesive systems does not vary for the studied parameters. MATERIAL AND METHODS: Composite resin (Filtek Z250) buildups were bonded to untreated (prophylaxis) and treated (bur-cut or SiC-paper) enamel surfaces of third molars after application of four self-etching and two etch-and-rinse adhesive systems (n=6/condition): Clearfil SE Bond (CSE); OptiBond Solo Plus Self-Etch (OP); AdheSe (AD); Tyrian Self Priming Etching (TY), Adper Scotchbond Multi-Purpose Plus (SBMP) and Adper Single Bond (SB). After storage in water (24 h/37°C), the bonded specimens were sectioned into sticks with 0.8 mm² cross-sectional area and the microtensile bond strength was tested at a crosshead speed of 0.5 mm/min. The mean bond strength values (MPa) were subjected to two-way ANOVA and Tukey's test (α=0.05). The etching patterns of the adhesive systems were also observed with a scanning electron microscope. RESULTS: The main factor adhesive system was statistically significant (p<0.05). The mean bond strength values (MPa) and standard deviations were: CSE (20.5±3.5), OP (11.3±2.3), AD (11.2±2.8), TY (11.1±3.0), SBMP (21.9±4.0) and SB (24.9±3.0). Different etching patterns were observed for the self-etching primers depending on the enamel treatment and the pH of the adhesive system. CONCLUSION: Although there is a tendency towards using adhesive systems with simplified application procedures, this may compromise the bonding performance of some systems to enamel, even when the prismless enamel is removed.

The aim of this study was to evaluate the early and 12-month bond strength of two adhesive systems (Single Bond-SB and One Step-OS) applied to demineralized dentin (WH) and demineralized/NaOCl-treated dentin (H). Twenty flat dentin surfaces were exposed, etched, rinsed and slightly dried. For the H groups, a solution of 10% NaOCl was applied for 60 s, rinsed (15 s) and slightly dried. The adhesives were applied according to the manufacturer's instructions and composite resin crowns were incrementally constructed. After 24 h (water-37ºC), the specimens was sectioned in order to obtain resin-dentin sticks (0.8 mm²). The specimens were tested in microtensile (0.5 mm/min) immediately (IM) or after 12 months of water storage (12M). The data (MPa) were subjected to ANOVA and Tukey's test (a=0.05). Only the main factors adhesive and time were significant (p=0.004 and p=0.003, respectively). SB (42.3±9.1) showed higher bond strengths than OS (33.6±11.6). The mean bond strength for IM-group (42.5±8.7) was statistically superior to 12M (33.3±11.8). The use of 10% NaOCl, after acid etching, did not improve the immediate and the long-term resin-dentin bond strength.

Este estudo teve o objetivo de observar a morfologia da interface dente-restauração de diferentes sistemas adesivos em cavidades MOD, por microscopia eletrônica de varredura (MEV). A hipótese do estudo foi de que a morfologia da interface adesiva poderia variar nas diferentes regiões da cavidade MOD, para algum dos 3 sistemas adesivos estudados. Preparos tipo MOD foram confeccionados em 12 terceiros molares humanos hígidos e restaurados com resina composta Filtek Z250 e os seguintes sistemas adesivos: ABF (n=4), Clearfil SE Bond (n=4) (sistemas adesivos autocondicionantes) e Single Bond (n=4) (sistema adesivo de condicionamento ácido total). Após 24 h de armazenamento em água destilada a 37ºC, os dentes foram secionados e preparados para MEV. A morfologia da interface de união variou com o sistema adesivo e com a região analisada. A hipótese do estudo foi aceita, pois a morfologia da interface de união refletiu as características do substrato dental e dos sistemas adesivos testados.

The purpose of this study was to assess the morphological characteristics of the tooth/adhesive interface using different adhesive systems in MOD restorations under scanning electron microscopy (SEM). The tested hypothesis was that the morphology of the bonding interface would vary in different areas of MOD restorations for the three adhesive systems. MOD cavities were prepared in 12 sound extracted human third molars and restored with Filtek Z250 composite resin and one of the following adhesive systems: Experimental ABF (n=4), Clearfil SE Bond (n=4) self-etching primers and Single Bond etch-and-rinse adhesive system (n=4). After 24-h storage in distilled water at 37ºC, teeth were sectioned and prepared for SEM. The interfacial morphology varied depending on the adhesive system and also on the evaluated area. The null hypothesis was accepted because the morphology of the tooth/adhesive interface reflected the characteristics of both the dental substrate and the adhesive systems.

Objetivou-se verificar a influência do tempo de armazenamento (24 horas ou 3 meses) no selamento marginal de restaurações de classe II e, além disso, verificar a correlação entre dois métodos de obtenção dos resultados nos testes de microinfiltração. Cavidades classe II foram confeccionadas em molares humanos íntegros, sendo as cavidades MO restauradas com ABF experimental (Kuraray Medical Inc.) + Z250 (3M ESPE) e as DO, com Single Bond (3M ESPE) + Z250. Após os diferentes tempos de armazenamento, empregou-se uma metodologia para provocar microinfiltração (ciclagem térmica e corante azul de metileno 0,5% por 4 horas) e os corpos-de-prova foram seccionados em 3 fatias. Três avaliadores calibrados atribuíram escores conforme o grau de infiltração, e também foram realizadas medidas morfométricas com ajuda do software ImageLab 2000. A análise de regressão de Pearson mostrou correlação altamente significante entre os valores obtidos pelos dois métodos de avaliação (r = 0,978, p < 0,001). Constatou-se que o adesivo ABF experimental apresentou menor infiltração marginal em relação ao adesivo Single Bond (p < 0,001), sendo que o tempo de armazenamento não influenciou no comportamento dos adesivos.

The aim of this study was to evaluate the influence of storage periods of 24 hours and 3 months on the microleakage of class II cavities. Two methods of assessing microleakage were also compared. Class II cavities were prepared in sound human molars. MO cavities were restored using ABF experimental (Kuraray Medical Inc.) + Z250 composite resin (3M ESPE), and DO cavities were restored using Single Bond (3M ESPE) + Z250. After different storage periods, specimens were thermocycled, immersed in a dye (0.5% methylene blue solution for 4 h) and longitudinally sectioned. Dye penetration was scored according to a 0-4 scale. The extent of microleakage was measured using the ImageLab 2000 program. A statistically significant correlation was verified between both evaluation methods (r = 0.978, p < 0.001). ANOVA revealed a statistically significant difference between the tested adhesive systems regarding microleakage (p < 0.001), although it was not influenced by the different storage periods.