pH studies in modern dental alginates

Abstract The change in pH during setting of seven modern dental alginates has been studied with a view to developing novel colorimetric setting indicators. Final pH at setting time varied considerably among materials, and in all cases was still changing. One material became acidic at setting time, while others would probably have done so later, and one material showed a reversal of pH change during setting. From the typical rate of change of pH at setting time, it is concluded that a novel setting indicator would need to be sensitive to pH changes of the order of 0·1 pH. A possible alternative method of indicating setting time is discussed.