Influence of specimens' design and manufacturing process on microtensile bond strength to enamel: laboratory and FEA comparison

Autor(es)

Fernanda Tranchesi Sadek ^[1] ; Antônio Muench ^[2] ; Isis Andréa Poiate ^[3] ; Edgard Poiate Junior ^[4] ; Paulo Eduardo Capel Cardoso ^[5]

Afiliação do(s) autor(es)

^[1] University of São Paulo. Department of Dental Materials - Brasil

^[2] University of São Paulo. Department of Dental Materials - Brasil

^[3] Federal Fluminense University. School of Dentistry. Department of Operative Dentistry - Brasil

^[4] University of São Paulo. Department of Mining and Petroleum Engineering - Brasil

^[5] University of São Paulo. Department of Dental Materials - Brasil

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 13, n. 2, p. 253-260, 2010-06-00.

Resumo

This study evaluated the effect of specimens' design and manufacturing process on microtensile bond strength, internal stress distributions (Finite Element Analysis - FEA) and specimens' integrity by means of Scanning Electron Microscopy (SEM) and Laser Scanning Confocal Microscopy (LCM). Excite was applied to flat enamel surface and a resin composite build-ups were made incrementally with 1-mm increments of Tetric Ceram. Teeth were cut using a diamond disc or a diamond wire, obtaining 0.8 mm² stick-shaped specimens, or were shaped with a Micro Specimen Former, obtaining dumbbell-shaped specimens (n = 10). Samples were randomly selected for SEM and LCM analysis. Remaining samples underwent microtensile test, and results were analyzed with ANOVA and Tukey test. FEA dumbbell-shaped model resulted in a more homogeneous stress distribution. Nonetheless, they failed under lower bond strengths (21.83 ± 5.44 MPa)c than stick-shaped specimens (sectioned with wire: 42.93 ± 4.77 MPaª; sectioned with disc: 36.62 ± 3.63 MPa b), due to geometric irregularities related to manufacturing process, as noted in microscopic analyzes. It could be concluded that stick-shaped, nontrimmed specimens, sectioned with diamond wire, are preferred for enamel specimens as they can be prepared in a less destructive, easier, and more precise way. (AU)

• Processo FAPESP: 05/60644-2 - Influencia da geometria e modo de obtencao dos corpos-de-prova no teste de microtracao.
• Beneficiário: Fernanda Tranchesi Sadek
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado