997 resultados para self-etching cement resins


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Objectives: the purpose of this study is to employ optical microscopy to measure the thickness of the hybrid layer and the penetration (tags) of an aggressive self-etching adhesive system into sound dentin.Methods: occtusat cavities were prepared in 40 extracted human posterior teeth. The prepared teeth were randomly assigned to four experimental groups with 10 specimens each. The self-etching adhesive system Adper Prompt L-Pop was applied to the dentin surface as follows: Group 1: cavosurface enamel was etched for 60 s and dentin for 20 s with 35% phosphoric acid get, immediately followed by application of the self -etching adhesive with a brush to the entire cavity for 15 s; Groups 2, 3, and 4: no pre-etching was performed, and the self -etching adhesive was applied to both enamel and dentin for 15, 30 and 45 s, respectively. After curing, the cavities were fitted with composite resin Fittek Z250. Afterwards, the teeth were decalcified and the restorations were carefully removed for later embedding in paraffin. The specimens were serially sectioned at 6 mu m of thickness and sequentially mounted in glass slides. These sections were stained with Brown and Brenn staining for posterior analysis and measurement of the hybrid layer and resin tags on a tight microscope with a micrometric ocular 40/075. The results were submitted to analysis of variance at the 5% level.Results: whenever there was significance, the Tukey test was applied at the 5% level. The specimens receiving application of acid etching before the selfetching. adhesive displayed a larger thickness of the hybrid layer; on the other hand, specimens receiving only application of the self -etching adhesive on dentin for 15, 30 and 45 s exhibited similar thickness of the hybrid layer. As regards the resin tags, no statistically significant differences could be found between the study groups.Conclusions: it could be concluded that the increase in the time of application of the self-etching adhesive Adper Prompt L-Pop did not significantly influence the formation and thickness of hybrid layer, as well as its penetration into the sound dentin surface. (c) 2005 Elsevier Ltd. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Objectives: The incorporation of antibacterial agents into adhesive systems has been proposed to eliminate residual bacteria from dentine. This study used the agar diffusion method to evaluate the antibacterial activity of Clearfil Protect Bond (CPB), Clearfil SE Bond (CSEB), Clearfil Tri-S Bond (C3SB) and Xeno-III (XIII) self-etching adhesive systems, with or without light-activation, against cariogenic bacteria, and to assess the influence of human dentine on the antibacterial activity of these materials.Methods: An aliquot of 10 mu l per material (and individual components) were pipetted onto paper and dentine discs distributed in Petri dishes containing bacterial culture in BHI agar. Positive control was 0.2% chlorhexidine digluconate (CHX).Results: After incubation, the adhesive components of CPB and CSEB, liquid A of XIII and C3SB did not present antibacterial activity when applied to paper discs. The non-light-activated CPB primer + adhesive promoted the greatest inhibition of Streptococcus mutans (p < 0.05), whereas with light-activation, there was no significant difference between primer + adhesive and primer alone. For Lactobacillus acidophilus, CPB primer presented the greatest antibacterial activity in both light-activation conditions (p < 0.05). Regarding the dentine discs, only CHX promoted an inhibitory effect, though less intense than on paper discs (p < 0.05). CHX presented greater antibacterial activity against S. mutans than against L. acidophilus (p < 0.05).Conclusions: Light-activation significantly reduced the antibacterial activity of the self-etching adhesive systems; MDPB incorporation contributed to the effect of adhesive systems against cariogenic bacteria; the components eluted from the adhesive systems were not capable to diffuse through 400 mu m-thick dentine disc to exert their antibacterial activity against cariogenic bacteria. (C) 2008 Elsevier Ltd. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Purpose: The aim of this study was to evaluate the influence of dentin abrasion on the microshear bond strength of two self-etching adhesive systems, using either an ultrasound diamond bur or a high-speed diamond bur.Materials and Methods: Twenty noncarious human third molars were sectioned mesiodistally into halves. The enamel was ground to expose a flat dentin surface on both sections. The dentinal surfaces were randomly assigned to two groups, depending on the method of smear layer preparation: ultrasound diamond bur (UB) or conventional diamond bur (CB). The prepared dentin surfaces received one of two self-etching systems: Clearfil SE Bond (CF) and One-Up Bond F (OB). A composite cylinder with a 0.95-mm diameter was bonded to each specimen and the microshear bond test was performed. The results were expressed in MPa and were subjected to two-way analysis of variance (ANOVA) and Tukey's test (alpha = 0.05).Results: There was no significant difference in dentin bond strength when comparing the conventional and ultrasonic abrasion methods. When the adhesive systems were compared, Clearfil SE Bond achieved higher bond strength means than did One-Up Bond F.Conclusion: The dentin surface preparation method did not influence the microshear bond strength and the Clearfil SE Bond adhesive system, independent of bur type used, Clearfil SE Bond showed higher bond strengths than did the One-Up Bond F adhesive system.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The effect of application methods and dentin hydration on the bond strength of three self-etching adhesives (SEA) were evaluated; 195 extracted bovine incisors were used. The buccal surface was ground in order to expose the dentin, which remained 2-mm minimum thickness, measured by a thickness meter through an opening on the lingual surface. Adper Single Bond 2 (TM) was used for the control group. The SEA were applied following two modes of application: passive or active and two hydration states of the dentin surface-dry and wet. After light-curing, composite buildups were made using Grandio (TM) composite. The specimens were sectioned and tested with a microtensile bond strength test. The application method and the hydration state resulted in statistical differences (p = 0.000) making the values of active application for mu TBS to dentin higher than passive application. The wet surfaces showed higher mu TBS to dentin ratios than dry surfaces. There were no statistical differences in mu TBS among the SEA tested but there were differences regarding to control group.

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This study evaluated the cohesive strength of composite using self-etching adhesive systems (SE) in the lubrication of instruments between layers of composite. The specimens were made by using a Teflon (R) device. SE were used at the interface to lubricate the instruments: Group 1(G1) - control group, no lubricant was used; Group 2(G2) -Futurabond (R) M; Group 3(G3) - Optibond (R) All-In-One; Group 4(G4) - Clearfil (R) SE Bond; Group 5(G5) - Futurabond (R) NR; Group 6(G6) - Adper (R) SE Plus; Group 7(G7) - One Up Bond (R) F. Specimens were submitted to the tensile test to evaluate the cohesive strength. Data were submitted to the ANOVA and Tukey tests. ANOVA showed a value of p = 0.00. The average means (SD): G2 = 11.33(+/-3.44) a, G3 = 15.36(+/-4.06) ab, G4 = 18.9(+/-4.72) bc, G7 = 19.62(+/-4.46) bc, G5 = 21.02(+/-5.09) bc, G6 = 23.39(+/-4.17) cd, and G1 = 28.49(+/-2.89) d. All SE decreased the cohesive strength of the composite, except for Adper (R) SE Plus.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Background and Objectives. The adhesion of dental materials is important for the success of treatment. The aim of this study is to evaluate the bond strength of a composite resin applied with a self-etching adhesive system in different dentins after irradiation with Er:YAG and Nd:YAG lasers, observing their morphologic pattern using Scanning Electronic Microscopy (SEM). Materials and Methods. The buccal surface of 72 bovine incisors was worn until exposure of medium depth dentin. The specimens were divided into three groups; GI: normal, GII: demineralized and GIII: hypermineralized dentin. These were also divided into two subgroups; A-irradiated for 30 s with Er:YAG laser in noncontact mode at 40 mJ and 6 Hz and B- irradiated for 30 s with Nd:YAG laser in contact mode at 60 mJ and 10 Hz. The adhesive system Clearfil SE. Bond (Kuraray) and composite resin Tetric Ceram (Vivadent) were applied on the irradiated area by the incremental technique. After storage for 24 h in distilled water at 37 degrees C, the specimens were submitted to the shear strength test in a universal testing machine (EMIC) at a crosshead speed of 1.0 mm/min. Other specimens were made to be analyzed by SEM. Results. The results were statistically analyzed by Analysis of Variance and the Tukey test. Regardless of the type of dentin, the bond strength of specimens irradiated with the Nd:YAG laser (8,94 +/- 2,07) was higher compared to specimens irradiated with the Er:YAG laser (7,03 +/- 2,47); the highest bond strength was obtained for the group of hypermineralized dentin irradiated with the Nd:YAG laser. The SEM analysis showed that the Er:YAG laser caused opening of tubules and the Nd:YAG laser produced areas of fusion as well as regions of opening of dentinal tubules. Conclusions. The dentin showed different morphological patterns and the laser promote alterations on their surfaces, influencing the bond strength of the composite resin. (C) 2010 Laser Institute of America.

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Purpose: To evaluate the effect of surface hydration state and application method on the microtensile bond strength of one-step self-etching adhesives systems to cut enamel.Materials and Methods: One hundred ninety-five bovine teeth were used. The enamel on the buccal side was flattened with 600-grit SiC paper. For the control group, 15 teeth received Adper Single Bond 2, applied according to manufacturer's recommendations. The other specimens were divided into three groups according to the adhesive system used: Futura Bond M (FM; Voco), Clearfil S-3 Bond (CS; Kuraray), and Optibond All in One (OA; Kerr). For each group, two hydration states were tested: D: blown dry with air; W: the excess of water was removed with absorbent paper. Two application methods were tested: P (passive): the adhesive was simply left on the surface; A (active): the adhesive was rubbed with an applicator point. A coat of Grandio composite resin (Voco) was applied on the surface. The teeth were sectioned to obtain enamel-resin sticks (1 x 1 mm), which underwent microtensile bond testing. The data in MPa were submitted to a three-way ANOVA and Tukey's test (alpha = 5%).Results: The ANOVA showed significant differences for application method and the type of adhesive, but not for hydration state. For the application method, the results of Tukey's test were: P: 31.46 (+/-7.09)a; A: 34.04 (+/-7.19)b. For the type of adhesive, the results were: OA: 31.29 (+/-7.05)a; CS: 32.28 (+/-7.14)a; FM: 34.68 (+/-7.17)b; different lower-case letters indicate statistically significant differences.Conclusion: Active application improved the bond strength to cut enamel. The adhesive Futurabond M showed the highest bond strength to cut enamel.

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Purpose: To test the null hypothesis that beveling and/or etching enamel would not affect the 18-month clinical performance of the self-etching adhesive Clearfil SE Bond (CSEB) in noncarious cervical lesions (NCCL). Methods: With Institutional Review Board approval, 34 patients were enrolled in this study. A total of 120 NCCL was selected and assigned to four groups: (1) CSEB was applied without any cavity preparation; (2) CSEB was applied after beveling enamel; (3) CSEB was applied after etching enamel for 15 seconds with 35% phosphoric acid; (4) CSEB was applied after beveling and etching enamel. A microfilled composite resin was used for all restorations. Resuts: At 6 months after initial placement, 120 restorations (a 100% recall rate) were evaluated. At 18 months, 87 restorations (a 72.5% recall rate) were available for evaluation. A survival rate of 100% was measured for all groups at both 6 and 18 months. Sensitivity to air decreased significantly only for Group 3 (no bevel+acid etch) from baseline to 18 months without statistical changes from 6 months to 18 months. None of the other parameters resulted in significant differences for any of the four groups. However, when data were pooled, both the overall marginal discoloration and the overall marginal adaptation were significantly worse at 18 months than at baseline, while sensitivity to air decreased significantly from baseline to 18 months. The 18-month survival rate of the self-etching adhesive Clearfil SE Bond was not improved by enamel bevel or by enamel etching. Both overall marginal adaptation and overall marginal discoloration were worse at 18 months than at baseline.