Metal Ceramic Plastic Braces Testing
The Challenge
Metal braces are the most common type of braces for correcting misaligned teeth, and are typically made from high quality stainless steel or titanium. The components of metal braces include the brackets that physically attach to the teeth, bonding material like an adhesive to secure the brackets to the teeth, arch wire that connects the brackets together, and elastic which is typically referred to as O-ring material. In recent years, clear braces produced from plastic or ceramic have become a popular alternative to metal braces for cosmetic reasons. For a patient that requires braces, the preparation and application of braces are both expensive and time intensive. It is imperative that braces remain intact during application and during the patient's daily use of eating and drinking. Given the complexity of different patients and the multiple components and materials associated with braces, testing all parts and use cases can be overwhelming.
In order to test each component in a set of braces, we recommend using a Universal Testing System, such as the 6800 Series or 3400 Series systems with Bluehill® Universal software. Bluehill Universal's flexible user interface enables users to quickly set up different methods for tensile, compression, flex, peel, tear, and friction tests. This allows users to test the compressive strength properties of the brackets, peel properties of the adhesive, and tensile strength of both the metal wire and O-ring material. For testing the brackets, we recommend using 2-inch compression platens. When testing the adhesive, we recommend performing a 90° peel test with the adhesive bonded to substrates that mimic the tooth. Depending on the thickness of the metal wire, pneumatic cord and yarn grips may be the most preferred gripping solution for wire tensile tests. Finally, for testing the elastomeric O-ring material, Instron® offers a specialized O-ring fixture designed for measuring stiffness, strain, and ultimate tensile strength properties for a variety of O-ring sizes.