dental02.jpg (11342 bytes)Fundamentals of
Dental Materials

frelogo01.gif (5798 bytes)

Gypsum Products, Dental Waxes, and Impression Materials

Contact Us - Tell A Friend - Make a Donation - Free-Ed.Net Home   Bookmark and Share

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.

David L. Heiserman, Editor

Copyright 2009-10, Free-Ed.Net
All Rights Reserved

Revised: May 22, 2017