Mechanical property tests such as the diametral tensile, uniaxial tensile, biaxial flexural, shear, and transverse strength tests are commonly used for assessing the bond that forms between dental composites and dental substrates such as dentin and enamel. These tests, while providing useful information, can be difficult to interpret because of the interaction of many competing failure modes that accompany failure, not only at the interface or interphase, but also in the substrate and/or in the composite. Shear bond testing to assess the bond strength between polymeric adhesives and mineralized tissue is widely used due to the ease of specimen preparation and testing. We have designed and developed a new shear test protocol that minimizes the tensile forces at the interface and maximizes the shear forces. Because our bonded surfaces are very small (~0.4 mm2), we are able to test many specimens on a single surface of enamel or dentin, thereby aiding in the conservation of teeth. Additionally, we can perform regional mapping of the tooth structure and can reach temperature equilibrium conditions rapidly, which permits accelerated durability studies.
Citation: A Microshear Test to Measure the Bond Between Dental Composites and Dental Substrates
Pub Type: Others
bond strength, dental composites, dental substrates, microshear