gypsum
Pronunciation: /ˈdʒɪp.səm/
A calcium sulphate–based material used in dental laboratories to fabricate stone or plaster models from impressions.
Full Definition
Gypsum products—including dental plaster (Type I/II), dental stone (Type III), die stone (Type IV), and high-strength die stone (Type V)—are the principal materials for creating working models and dies in traditional dental laboratories. Each type differs in water-to-powder ratio, expansion, compressive strength, and surface hardness. Editors reviewing dental laboratory documents should be aware that 'gypsum' is the umbrella term, while 'stone' and 'plaster' denote specific subtypes with distinct clinical applications. The term 'gyspum' is a common typographic error and should be corrected.
Usage
Usage note: Correct the common misspelling 'gyspum.' When the specific type matters clinically or technically, use the precise descriptor (e.g., 'Type IV die stone') rather than the generic 'gypsum.'
In Context
- "The model was poured in Type IV gypsum to ensure sufficient surface hardness for die fabrication." — Laboratory Procedure Record
- "Editors should distinguish between 'gypsum' as a generic material class and 'dental stone' as a specific subtype when reviewing technical specifications." — Style Guidance Note