National Dental Assisting Examining Board (NDAEB) Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare for the National Dental Assisting Exam with comprehensive quiz questions, including multiple choice and detailed explanations. Equip yourself for success!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

Among impression materials, which one has the highest rate of dimensional stability?

Alginate
Reversible hydrocolloid
Polyester
Polyether

The correct answer is: Reversible hydrocolloid

The correct choice is polyester. Among impression materials, polyester is known for its excellent dimensional stability, which means it maintains its shape and volume over time without significant distortion. This property is crucial in dental procedures, as any changes in the impression dimensions can lead to inaccuracies in the final restoration or appliance being created. Polyester materials can be used for various applications, including making impressions for crowns, bridges, and dentures, and their low shrinkage and stability over time make them favorable in scenarios where precision is paramount. Reversible hydrocolloid is not the correct choice because, while it does have some dimensional stability, it generally has a higher degree of water absorption and can distort if exposed to changes in temperature or humidity. Alginate has a good balance between ease of use and accuracy but is less stable in dimension over time due to its significant water content and tendency to shrink. Polyether is known for good dimensional stability as well, but it is not as stable as polyester in terms of maintaining its shape after setting.