EFEITO DA FOTOATIVAÇÃO PROLONGADA DE ADESIVOS AUTOCONDICIONANTES NA ADESÃO À DENTINA / Effect of prolonged exposure time of one-step self-etching in dentinbonding

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

24/02/2012

RESUMO

This study evaluated the effect of prolonged exposure times on immediate (IM) and 6-month (6M) adhesive properties: degree of conversion within hybrid layer (DC), silver nitrate uptake (SNU) and resin-dentin bond strenght (μTBS) for three one-step self-etch adhesive systems (Adper Easy Bond [EB], Clearfil S3 Bond [CS3] and Go [GO]).Ninety caries-free extracted molars were included in this study being 45 for μTBS and SNU (n=5) and 45 for DC (n=5). The dentin surfaces were bonded according to the manufacturers instructions, but they were light-cured for 10, 20, and 40 s at 600mW/cm2. Bonded teeth for the μTBS test were sectioned in order to obtain stick-like specimens (0.8mm2) and tested under tensile stress 0.5mm/min). Two bonded sticks from each tooth were analyzed by scanning electron microscopy for SNU. The DC within the hybrid layer were evaluated with micro-Raman spectroscopy. All tests were performed IM and at 6M. Data were analyzed by a threeway repeated measures ANOVA and Tukeys test (alpha=0.05).The prolonged exposure times increased the DC () [10s- 67.319.5; 20s- 84.6 12.3 e 40s- 82.9 13.1] for all adhesives and decreased the SNU ()[10s- 24.8 13.2; 20s- 13.3 7.5 e 40s- 13.5 9.3] significantly for all adhesives; however significant improvements in the μTBS (MPa) [10s- 17.3 3.7; 20s- 31.9 4.9 e 40s- 25.0 3.7] and stable bond strengths after water storage [IM- 25.2 7.3; 6M- 24.2 7.2] were observed only for CS3. EB [IM- 35.9 4.7; 6M- 28.0 6.0] and GO [IM- 25.6 5.0; 6M- 14,3 3,7] decreased the μTBS after 6 months. The prolonged exposure times improved the DC within the hybrid layer and reduced the SNU for all adhesives, however this did not prevent the degradation of the adhesive interface.

ASSUNTO(S)

polimerização resistência à tração adesivos dentinários análise spectral raman dentin-bonding agents tensile strength polymerization raman spectrum analysis odontologia

ACESSO AO ARTIGO

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