Alternative methodology for flexural strength testing in natural teeth

Abstract

The use of natural teeth for performing in vivo , in situ and/or in vitro studies has been widely observed in the dental field. The mechanical behavior of teeth subjected to masticatory efforts is commonly used as a variable of response. In conditions of malocclusion, the most relevant component accounting for the integrity of the dental structure is non-axial (flexural). This force, while acting on a tooth in function in the oral cavity, generates a similar situation as that of a beam in balance supporting a load concentrated on its free extremity. Based on this configuration, a methodology has been developed to investigate the behavior of teeth subjected to this kind of efforts, taking into consideration specific aspects of the tested teeth, such as the transversal section area and the moment of inertia. For determination of the transversal section area an image analysis program was used. For assessment of the other variables, a C++ language program was implemented utilizing the Borland Compiler C++ Builder, version 1.0, for Windows (Borland International, USA). The applicability of the developed methodology is illustrated in this article using bovine teeth. Our findings indicate that more accurate data can be obtained with the application of this methodology and that it is suitable for studies testing the flexural strength of extracted teeth, as a variable of response.

Flexural Resistance of Esthetic Materials Used by Indirect Restoration: A Comparative in vitro Study

“…All these materials have excellent aesthetic results, making the restoration almost imperceptible, but like all restorative material they have their disadvantages; in this case, their limited resistance to the forces produced inside the oral cavity. One of these forces is flexion (Reis & Borges, 2005), which can be tested using a three-point flexure test, a four-point flexure test or a biaxial flexure test. The threepoint analysis employs rectangular bar samples submitted to a central loading, creating a non-uniform stress field (Fischer et al, 2008) and producing compressive stress where the load is applied and tensile stress on the lower surface of the specimen (Della Bona et al, 2008).…”