FORMULATION AND SETTING TIMES OF SOME CALCIUM ORTHOPHOSPHATE CEMENTS - A PILOT-STUDY

Calcium orthophosphates which either can be formed by precipitation at room or body temperatures or by reactions at higher temperatures have been reviewed. Most formulations of cements contain at least one or m ore acidic components and one or more basic components which react whe n the powder is mixed with water. Several combinations of reactants ar e possible in the systems of calcium phosphates and even combinations with calcium phosphates containing sodium, potassium, magnesium, zinc, carbonate or chloride are thought to be useful. Furthermore, other co mpounds can be added as accelerators or retarders of the setting react ion or as promoters of bone ingrowth. In this study, over 100 formulat ions have been tested on their ability to set upon mixing with water. The initial and final setting times were measured with Gilmore needles .