National Dental Assisting Examining Board (NDAEB) Practice Exam

Impression materials that are repelled by moisture are known as what?

1. Hydrophilic

2. Hydrophobic

3. Imbued

4. Hydra-resistant

The correct answer is: Hydrophobic

Impression materials that are repelled by moisture are referred to as hydrophobic. This means that these materials do not absorb water and instead tend to resist wetting. Hydrophobic impression materials are often used in situations where moisture could interfere with the accuracy of the impression. Typically, hydrophobic materials create a better dimensional stability and detail reproduction in environments where moisture control can be challenging. The hydrophobic nature of these materials allows them to maintain integrity while capturing the necessary details of the oral structures, leading to more precise results in dental applications. In contrast, hydrophilic materials, which are designed to absorb moisture, are beneficial in wet environments but may not provide the same level of stability as hydrophobic materials. The other terms such as imbued and hydra-resistant do not specifically designate the moisture-repelling characteristics that define hydrophobic materials. Thus, understanding the use and application of hydrophobic impression materials is essential for effective dental practice.