HESI General Chairside Assisting Practice Exam

Which method is not used to dispense elastomeric impression materials?

1. Cartridge system

2. Pre-filled syringes

3. Powder/liquid

4. Automated dispensers

The correct answer is: Powder/liquid

The method that is not employed to dispense elastomeric impression materials is the powder/liquid approach. Elastomeric materials are primarily composed of base and catalyst components that are pre-measured or combined in specific ratios to form the impression material before use. The dispensing of these materials typically involves systems that allow for accurate mixing and application, such as cartridge systems, pre-filled syringes, and automated dispensers, which enable the proper handling and delivery of the material without the need for manual mixing of powder and liquid components. In contrast, powder/liquid systems are more commonly associated with other types of materials, such as gypsum or alginate, where the two components need to be mixed to activate the material. In the context of elastomeric impression materials, such as polyvinyl siloxane or polyether, the focus is on precise ratios and consistent mix quality provided by the aforementioned dispensing methods.