1-16. PREPARATION AND USAGE OF POLYCARBOXYLATE CEMENT
a. Equipment. The equipment required for mixing polycarboxylate cement consists of a nonporous, polymer paper pad, a glass mixing slab, a stainless steel spatula, and a matched set of powder and liquid. See figure 1-6.
b. Powder and Liquid. Dispense the powder and liquid according to manufacturer's instructions (to achieve the desired consistency). Do not predispense and allow to sit. Loss of moisture will cause the liquid to thicken.
c. Mixing. Mixing is done by rapidly blending the powder and the liquid for 30 seconds on a polymer paper-mixing pad. Ensure that all the powder is incorporated into the mix. If extended working time is desired, mix on a cooled glass slab.
Figure 1-6. Setup for mixing polycarboxylate cement.
d. Characteristics of a Completed Mix. The correct cementing mix is more viscous than zinc phosphate cement. Because of its composition, the cementing mix flows adequately under pressure.
e. Precautions. The following precautions should be observed.
(1) The interior of restorations and tooth surfaces must be free of saliva.
(2) The mix should be used while it is still glossy, before the onset of cobwebbing.
(3) The powder and liquid should be stored in stoppered containers under cool conditions. Loss of moisture from the liquid will lead to thickening.
|David L. Heiserman, Editor||
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Revised: May 22, 2017