American Board of Dental Examiners (ADEX) Dental Hygiene Licensing Examination 2025 – 400 Free Practice Questions to Pass the Exam

The correct answer is that gypsum known as plaster of Paris refers to Type I gypsum. Type I gypsum is primarily made for laboratory use and is characterized by its fast setting time and ability to form a soft, porous texture when mixed with water. This type of gypsum is less commonly used in clinical settings compared to other types, specifically because it is not ideal for creating models or casts that require higher strength and durability.

In contrast, the other types of gypsum (Type II, Type III, and Type IV) serve more practical and specialized functions in dentistry and dental hygiene. Type II gypsum, for example, is used for making dental casts and has improved strength properties over Type I. Type III is a dental stone that is more refined and stronger than Type II, making it suitable for precision molds and models. Type IV is a high-strength stone that is frequently used for making working dies where extra durability is essential.

Consequently, plaster of Paris (Type I) stands out for its specific properties and the limited contexts in which it is applied compared to the other types, which have broader applications in dental practices.