Bond strength evaluation of light, self and dual-cured adhesive systems for indirect composite restorations / Avaliação da resistencia de união de sistemas adesivos de dupla-presa, fotoativados e autopolimerizavel indicados para cimentação de peças proteticas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The purpose of this study in vitro was to evaluate the tensile bond strength (µTBS) of light-, self- and dual-cured dentin adhesive systems using foundation of composite blocks with resinous agents. Thirty-six third molars caries-free were extracted and sectioned perpendicully to the long axis, in the third occlusal area of the coronary portion with a diamond disk of high concentration and scorched with 400 and 600 grit SiC, exposing a surface dentinária plane of medium depth without enamel remainder, observed through the visual criteria. The teeth were randomly divided into six experimental groups accorded with the foundation systems (n=6): Group 1-Single Bond/3M-ESPE (SB) and Group 2-Scotchbond Multipurpose Plus/3M-ESPE (SBMP), in association with the resinous cement Rely X/3M-ESPE (RX); Group 3-Prime &Bond NT/Dentsply (PB), and Group 4 Prime &Bond NT + Self-cure Activator/Dentsply (PBA), associated the resinous cement Enforce/Dentsply (EN); Group 5-Clearfil SE Bond/Kuraray (CSB) and Group 6 ED Primer/Kuraray (ED), in association with the resinous cement Panavia F/Kuraray (PF). After the application of the systems according with the manufacturer s instruction, composite blocks Clearfil APX (Kuraray) were fastened with approximately 2 mm thick, with the resinous cement respective. The groups 1, 3 and 5 had the adhesive light-cured previously and after the foundation for 40 seconds. In the groups 2,4 and 6 were used the dual adhesive without initial lightactivated and all light-cured system for 40 seconds, only after the foundation. The samples were vertically, buccal-lingual (VL) and mesiodistal (MD) sectioned, resulting specimens in form of toothpicks with a cross-sectional area of approximately 0,8 mm2. Four specimens from each sample were tested in a microtensile device coupled in an universal testing machine (4411 Instron), at a crosshead speed of 0.5 mm/min. The results were expressed in MPa and statistically analysed by analysis of variance (only facto r) and Tukey test (5%). The medium values of ?TBS (MPa) were the following: Group 1 (SB/RX) = 26.74 ± 7.44 ab; Group 2 (SBMP/RX) = 32.89 ± 6.16 a; Group 3 (PB/EN) = 26.11 ± 4.48 ab; Group 4 (PBA/EN) = 25.30 ± 6.42 ab; Group 5 (CSB/PF) = 16.82 ± 5.52 bc and Group 6 (ED/PF), = 11.20 ± 6.79 c. In the medium values of TR the G4 had lower rank than the other groups, excepted to the observed in the G6. The group 2 (SBMP/RX) showed larger µTBS than the groups 5 and 6, which used self-etching adhesive. In comparison among adhesive systems from the same manufacturer and with the same resin cement, there was not significant difference among them, except for the products of Dentsply Company

ASSUNTO(S)

dentina dental adhesives adesivos dentarios dentin

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