The use of film thickness to measure working time of zinc phosphate cements

A method is proposed to quantify the working time of zinc phosphate cement based on sequential measurement of viscosity. The method was used to measure the extension of working time resulting from reduced mixing temperatures. Premixing small amounts of powder prior to standard mix was shown to be ineffective at extending working time. The addition of water to the cement was shown not to affect working time but did decrease the setting time of the cement.