Fundamentals
of
Dental Materials
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| Gypsum Products, Dental Waxes, and Impression Materials |
| 3-21. MIXING AND SETTING TIME The best method of controlling the gelation time of alginate-type hydrocolloid materials is to alter the temperature of the water used in the mix. The higher the temperature of the water, the faster gelation will occur. Higher temperatures accelerate the chemical reaction. The temperature of the water must be regulated carefully within a few degrees of that recommended by the manufacturer to obtain a constant and reliable gelation time. The average recommended temperature of water is 70o F (21o C). Changing the water-powder ratio and the mixing time will alter the gelation time, but these methods of control also impair certain properties of the material. The amount of the retarder in the material can be regulated only by the manufacturer since the action of the retarder changes the nature of the material. |
| Primary Content Providers: The U. S.
Army, The U.S. Navy Ancillary Content and Online Version: David L. Heiserman Publisher: SweetHaven Publishing Services |
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SweetHaven Publishing Services |