Orthodontic Assistant Practice Exam

How should gypsum materials used for orthodontic procedures be stored?

1. In a humid container

2. In a sealed plastic bag

3. In an airtight dry container

4. At room temperature without a cover

The correct answer is: In an airtight dry container

Gypsum materials, which include dental plaster and stone used in orthodontics, require specific storage conditions to maintain their quality and prevent deterioration. Storing them in an airtight dry container is the best practice because gypsum is hygroscopic, meaning it has the ability to absorb moisture from the environment. If exposed to humidity, the material can clump, harden improperly, or lose its suitability for use in creating molds and casts. Using an airtight dry container protects gypsum from moisture and environmental factors, ensuring that it remains in optimal condition. This storage method prevents any chemical reactions that could result from humidity and keeps the material free from contaminants, ensuring reliability in clinical use. Storing gypsum in a humid container or at room temperature without a cover would allow moisture to enter and could compromise the material. Similarly, while a sealed plastic bag may provide some moisture protection, it does not ensure that the conditions inside remain dry enough for optimal storage, particularly over an extended period. Thus, an airtight dry container is the most effective method for preserving gypsum materials in orthodontic practice.