National Dental Assisting Examining Board (NDAEB) Practice Exam

When can the tubes of catalyst and base be interchanged?

1. When they are from different brands

2. When they are the same brand of impression material

3. When they are the same color

4. When they are unused

The correct answer is: When they are the same brand of impression material

The correct answer is that the tubes of catalyst and base can be interchanged when they are the same brand of impression material. This is crucial because each brand is formulated with specific chemical properties and ratios that dictate how the catalyst and base interact. Mixing products from different brands could lead to improper curing and the potential for compromised impressions. When the materials are from the same brand, it is highly likely that they have been designed to work together, meaning that their chemical compositions and intended uses are compatible. This compatibility ensures that the resulting material achieves the desired properties such as setting time, hardness, and overall performance. The other options suggest circumstances that do not guarantee compatibility. For instance, using different brands may introduce variations in formulation that could lead to inconsistent results. Color alone is not an indicator of compatibility; different brands can have the same color for different formulations. Lastly, being unused does not provide any assurance that two different products will work well together; it's the formulation, not the usage state, that determines compatibility.