Plaster of Paris application in the orthopedic for stabilization and immobilization of the fractured bone.
Chemical Formula of plaster of Paris
CaSO4.1/2 H2O Hemihydrated salt of calcium sulfate
The Exothermic reaction takes place in the formation of hard POP application. For plaster of paris formula
Plaster of Paris with chemical formula CaSO4.1/2 H2O contact with hot water and becomes molded and then in a hard state
CaSO4.1/2 H2O + 1/2 H2O –> CaSO4.H2O
Anhydrous hemihydrated calcium sulphate —–> Hydrated calcium sulphate (Gypsum)
The hardness of plaster depends on the use of hot water
The cast applied on the target of bone in different parts of the body
The material used for the application of Slab or Cast mentioned below
- Plaster of Paris
- Thermoplastic material
- Powdered Cotton Bandage
- Othocast
Types of Cast and Slab
Plaster of Paris Application in two manners one in full cover the surface that is called a cast. Another one which covers some parts of surface or parts called slab
Avoid tight and wrinkles while applying the cast and slab. plaster molded when it is wet to form the exact shape for immobilization
Slab
Slab means the plaster applied on any one of the surfaces of the target parts.
Apply the slab with appropriate cotton padding before application
Types of the slab as follows
Above elbow Back slab
Below elbow back slab
Below knee back slab
Volar slab
Plaster of Paris Application-CAST
Cast means plaster wind fully on the surfaces of the body. It covers full parts with the plaster to enhance the immobilization.
Below elbow cast
Above elbow cast
Below knee cast
Scaphoid cast
Bennett’s cast