Comparison of both cast materials
On a fibreglass cast one can put pressure already one hour after application. Plaster takes almost one day to harden completely. Fibreglass is more breakproof and lighter than plaster. The various colours of fibreglass bandages can improve the patient's acceptance.

But fibreglass bandages are more expensive. The polymerising material could cause allergic reactions on the skin. Therefore it is necessary to use gloves for the application (the patients skin is protected by stockinette and padding). In contrast to plaster, corrections on a fibreglass cast could not be done after hardening. Furthermore the non-polymerised bandages could only be used in a limited period of time, and the waste management of fibreglass is ecological difficult.

Which material should be used ?
The first cast for a fracture should be out of plaster. Usually it has to be removed after short times because of necessary corrections or after a swelling went down. So the cheaper plaster is the material of choice in the beginning. Later on, when the cast remains for a longer period and especially when a walking cast is applied, fibreglass should be used.