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A medicinal plaster made with a pastelike mixture of powdered black mustard, flour, and water, used especially as a counterirritant. Also called sinapism.
mustard plasterHerbal medicine
A poultice used to relieve minor pain; if left in place for too long a period, mustard plasters may cause vesiculation.
1. A material, usually plaster of Paris, that is applied to a part and allowed to harden in order to immobilize the part or to make an impression. In many settings, plaster of Paris has been replaced with synthetic cast materials, such as fiberglass.
2. A topical preparation in which the constituents are formed into a tenacious mass of substance harder than an ointment and spread upon muslin, linen, skin, or paper.
A powder, when mixed with water, that hardens to form a stonelike investment or model material. It is composed of a hemihydrate of gypsum (CaSO4·2H2O), which differs in compression strength and expansion coefficient according to how it is treated and rehydrated. There are four classes of dental plaster, with differing uses as materials for casts, impressions, or stone models, based on the differences of characteristics.
plaster of Paris
Gypsum cement, hemihydrated calcium sulfate (CaSO4·2H2O), mixed with water to form a paste that sets rapidly; used to make casts and stiff bandages.
salicylic acid plaster
A uniform mixture of salicylic acid spread on an appropriate base such as paper, cotton, or fabric. It is applied topically for use as a keratolytic agent.