Journal Article

Microtensile Specimen Attachment and Shape-Finite Element Analysis

SOARES C. J., SANTOS-FILHO P. C. F., ARMSTRONG S. R., SOARES P. V.

2008

Overview

Microtensile bond strength values are influenced by specimen shape and attachment method to the gripping device during testing. We hypothesized that stress distribution inside the testing specimen is affected by microtensile specimen shape and attachment method. Rectangular, hourglass-, and dumbbell-shaped specimens, all with a 1 mm2 cross-sectional testing region, were modeled as indirect ceramic restorations luted to dentin. Three specimen attachments were investigated: (1) posterior surface; (2) posterior, superior, and lateral surfaces; and (3) all surfaces. Qualitative and quantitative analyses were carried out according to von Mises’ criteria. Stress analysis showed a direct correlation between attachment modes and stress distribution, with shear stresses observed in models with less surface attachment. Increasing the number of faces for specimen attachment to the metallic gripping device resulted in a more homogeneous and regular distribution of stress, with tensile stress concentrated at the adhesive interface. Dumbbell-shaped specimens showed improved stress distribution compared with rectangular and hourglass-shaped specimens.

• Publisher: SAGE Publications,SAGE PUBLICATIONS, INC
• Subject: Bisphenol A-Glycidyl Methacrylate - chemistry / Dental Bonding - methods / Dental Materials - chemistry / Dental Porcelain - chemistry / Dental Stress Analysis - instrumentation / Dentin - ultrastructure / Elasticity / Finite Element Analysis / Humans / Imaging, Three-Dimensional / Lithium Compounds - chemistry / Materials Testing / microtensile testing / Polyethylene Glycols - chemistry / Polymethacrylic Acids - chemistry / Resin Cements - chemistry / stress distribution / Stress, Mechanical / Surface Properties / Tensile Strength