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Zinc Phosphate Cement

DA 122Dental Materials

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Common Uses

• Permanent cementation (luting)– Crowns, bridges– Inlays, onlays– Orthodontic bands and brackets

• Insulating Base

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Special Properties

• Reliable• Exothermic reaction-mix on cool glass

slab• Bonds to tooth structure by

mechanical interlocking

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Ratio

• Luting Consistency =• 1 measure of powder– Measure to “shoulder” of powder cap

• 6 drops of liquid• Base Consistency =– same ratio BUT add more powder to desired

thickness

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Armamentarium

• Cooled glass slab-slows exothermic reaction• Cement spatula• 2 x 2 gauze square• Zinc phosphate powder• Zinc phosphate liquid• Plastics filling instrument

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Zinc Phosphate Armamentarium

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Dispensing zinc phosphate cement: 6 drops liquid to 1 cap powder

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Dispensing anddividing powder

• Shake powder bottle to fluff, dispense 1 capful, then divided into 6 parts:

– Level powder to 1 mm of thickness

– Divide into 2 equal portions

– Divide each of these into quarters

– Then divide 2 sections into eighths

– Lastly-divide one of these into sixteenths.

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Mixing

– Smallest increment should be brought into liquid first• 1/16th

• Mix for 15 seconds to totally incorporate powder into liquid• Continue adding small increments,

mixing slowly, wiping both sides of spatula

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Mixing

• Use cooled glass slab w/ cement spatula

• Mix over large area of glass slab to keep material cool (controls exothermic reaction)-use figure 8 rotary motion when mixing

• Mix time: 2 minutes• Work time: 3 ½ minutes• Set time: 7 minutes

– Can be affected by cool temperature-takes longer to set

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Figure 8 mix over glass slab

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Clean-up

• Water (mixed with baking soda) + 2x2 gauze

• IMMEDIATELY prior to setting• If material has set, will need to use a temp

cement remover solution in an ultrasonic cleaner

• Discard unused powder left on mixing slab

13Luting = ½ - 1 inch string-elongation of material when lifted

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Roll into ball for base

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Appearance

• Luting = creamy

• Base = putty-like, rolled into a ball

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Common Brand Name

• Flecks

Copyright 2012 Porter & Chester Institute, Inc. All rights reserved