The comparative properties of plaster of Paris and plaster of Paris substitutes

Modern casting materials are becoming available in an increasing and bewildering variety. A series of tests has been devised to investigate the properties of these materials. They have been tested for strength, flexibility, lamination, fatigue life and radiolucency. Their properties have been compared with those of plaster of Paris in order that the role of the newer materials can be defined. It is suggested that the tests described might form the basis of a standard from which user trials could be designed to appraise the value of these materials in clinical practice.