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15 Cards in this Set
- Front
- Back
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What are silicate cements used for?
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Anterior restorations
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What is the powder composition of silicate cements?
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SiO2, Al2O3, F and Ca components
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What is the liquid composition of silicate cements?
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Phosphoric acid
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What is the setting reaction of silicate cements?
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Ca2+, Al3+, and F- ions leeched by acid attack forming phosphates
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What is an advantage of silicate cements?
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Fluoride release
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What are disadvantages of silicate cements?
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High solubility, degradation, loss of contour, short life span, and brittle
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What is/are the use(s) of zinc phosphate cements?
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Final cementation, high-strength base
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What is the powder composition of zinc phosphate cements?
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10% magnesium oxide and 90% zinc oxide
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What is the liquid composition of zinc phosphate cements?
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Phosphoric acid
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How can you alter the setting of zinc phosphate cements?
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Alter the temperature of the mixing slab NOT by changing the powder/liquid ratio
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What is the pH of zinc phosphate cements and why is it relevant?
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pH=2; Necessary to have pulpal protection
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What are the uses of zinc polycarboxylate cements?
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Restorative and orthodontic cementation; base cement
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What is the powder composition of zinc polycarboxylate cements?
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Zinc oxide, magnesium oxide, aluminum oxide, and bismuth oxide. SnF helps setting time, manipulative properties and strength
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What is the liquid composition of zinc polycarboxylate cements?
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Polyacrylic acid with itaconic acid
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How long is the working time of zinc polycarboxylate cements and what happens if you have gone over that time?
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2.5 minutes; cobweb appearance occurs and there are no longer any carboxyl groups left
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