Transcript DENT 1312 Materials I

DENT 1200 Materials I
CEMENTS
CEMENTS IN THIS UNIT
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Varnish and Liners ( Copalite, Ca OH)
Zinc Oxide Eugenol ( ZOE) & IRM
Zinc Phosphate
Polycarboxylate
Glass Ionomer
Composite
Cement in General
• Most dental cements are purchased from a dental supply company
in the form of powder and liquid or two tubes of paste which are
mixed together to form a paste or fluid which hardens in a short
period of time. Some cements come in a capsule and are mixed on
an amalgamator. The consistency depends upon the intended use.
Cements are used alone or in conjunction with other materials in
about 50% of all dental restorations.
• GENERAL USES OF ALL DENTAL CEMENTS
• 1. Capping
• 2. Insulating bases
• 3. Temporary restorations or temporary cementing.
• 4. Permanent cementing (luting) of fixed restorations.
• 5. Luting agents for orthodontic bands.
• 6. Root canal fillings, surgical cements and periodontal dressings
Important considerations
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Cements do not (in most cases) actually adhere to tooth
Cements dissolve and disintegrate in the mouth.
Period of usefulness in oral cavity is likely to be limited.
Cements are not considered truly permanent when used as a
restorative material.
Chemical and physical properties leave much to be desired.
• Manipulative techniques are especially important for good
results. With some cements, improper mixing can harm the teeth.
Poor mixing technique affect the strength of the finished product.
Manufacturers change ingredients and instructions. Please read
the manufacturer’s instructions each time a new package is
opened.
Dispensing cement rules
• FLUFF POWDER
• Dispense P before L
• Hold L bottle vertical
• Many offices mix on
pads- area of high
contamination?????
• Autoclave slabs ****
Luting Crown
permanent or provisional(temp)
metal(gold) or porcelain
Varnish
• A cavity varnish
(Copalite) is a liquid used
to seal dentinal tubules to
protect the tooth from the
chemical effects of some
cements and restorative
materials. It is applied
with a microbrush or
cotton pellot. DO NOT
USE with Composite.
Liners
Calcium Hydroxide DYCAL / Glass Ionomer VITREBOND
• STIMULATE
SECONDARY
DENTIN
FORMATION
• 1:1 mix 15 sec LC
• Fluoride- reduce
secondary caries
Zinc Oxide Eugenol
• ZOE IS THE LEAST
IRRITATING OF THE
DENTAL CEMENTS
SOOTHING
BASIC INGREDIENTS
POWDER- ZINC
OXIDE, FILLERS
LIQUIDEUGENOL, OIL OF
CLOVES
FORMS
• P/L
• 2 PASTE
Uses and Mixing of ZOE
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USES OF ZOE (not with composite)
TEMPORARY / SEDATIVE RESTORATIONS – BALL 1:1
Base – Ball 1:1
TEMPORARY LUTING – CREAMY 1:2
EQUIPMENT NEEDED
PAPER PAD
FLEX. SPATULA
POWDER AND LIQUID
2X2
ALCOHOL
NORMAL MIXING TIME 30-60 SEC.
SETTING TIME 3-5 MIN. (MOISTURE ACCELERATES)
Reinforced ZOE= IRM
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USE
LONG TERM TEMP.
RESTORATION
(not with composite)
• CAN BE PURCHASED
IN P/L FORM or
CAPSULE
FORM THAT NEEDS
TO BE TRITURATED.
Mixing IRM
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EQUIPMENT NEEDED
PAPER PAD
FLEX. SPATULA
IRM MATERIAL- POWDER & LIQUID OR CAPSULE
TRITURATOR IF NEEDED
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NEED TO USE A STROPPING MOTION TO MIX IRM.
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CONSISTENCY for temporary restoration NEEDS TO BE DRY AND
ALMOST FLAKEY. (For luting, creamy)
RECOMMENDED P/L RATIO IS 1:1 OR 6 TO 1 BY WEIGHT.
MIXING TIME IS 1 MINUTE, SET TIME IS ABOUT 5 MIN. AFTER START
OF MIX.
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TO MIX ADD ½ OF POWDER TO LIQUID, THEN 2 SMALLER
INCRIMENTS. Clean with alcohol.
ZINC PHOSPHATE
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ALSO CALLED CROWN AND BRIDGE CEMENT
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USED FOR:
LUTING Permanent RESTORATIONS
INSULATING BASE
CEMENTING ORTHODONTIC APPLIANCES ( NOT AS POPULAR NOW )
TEMPORARY RESTORATIONS
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LUTING - SHOULD BE LIKE ELMERS GLUE, FOLLOW SPATULA 1 INCH AND
BREAK. 1 cap of powder to 6 drops liquid
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BASE - SHOULD BE THICK, PUTTY, TACKY. 1 cap of powder to 5 drops liquid
ACIDIC IRRITATING TO THE PULP
EXOTHERMIC.
ZPO4
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MAIN INGREDIENTS
POWDER- ZINC OXIDE
LIQUID- ORTHOPHOSPHORIC ACID AND WATER
THE MOST CRITICAL INGREDIENT OF THE LIQUID IS WATER
IF WATER CONTENT IS ALTERED IN THE LIQUID IT CHANGES SETTING
TIME.
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WATER EVAPORATES – LIQUID WILL BE CLOUDY OR HAVE CRY•
STALS IN IT. IT WILL TAKE LONGER TO SET, INCREASE THE SET•
TING TIME
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MOISTURE INCORPORATED EITHER FROM GLASS SLAB BEING
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TOO COLD OR MOISTURE FROM THE AIR. IT WILL SET FASTER
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THUS DECREASed set time
MIXING
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INCORPORATED TOO FAST
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CEMENT WILL SET TOO
FAST!!
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WON’T GET AS MUCH
POWDER, MAKES A
WEAKER, MORE SOLUBLE
CEMENT.
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MORE ACIDIC –
POSSIBLY HARMING THE
PULP.
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CAN CAUSE
DISCOMFORT FOR THE
PATIENT.
• ZINC PHOSPHATE
MATERIAL IS
EXOTHERMIC!!!!!!! NEEDS
TO BE MIXED OVER A
LARGE AREA.
• IDEAL MIXING TIME IS 1 ½
MIN. - SETS IN 5-9 MIN.
• CLEAN UP WITH WATER
Control Set Times
• THE BEST WAY TO CONTROL THE SET IS TO
HAVE THE GLASS SLAB AT 68 DEGREES,
INCORPORATE THE POWDER SLOWLY
OVER A LARGE AREA OF THE SLAB, AND
ADD IN SMALL AMOUNTS.
• IF SETTING TIME IS INCREASED- MATERIAL
IS SLOWER TO SET, takes longer
• IF SETTING TIME IS DECREASEDMATERIAL SETS FASTER, accelerated
ZPO4
• P&L
• Mix on slab, divide P
Polycarboxylate Cement
• Brand name- DURELON
• Use- Perm Luting
• ADV- ease of mix
adheres(enamel
st.steel)
less acidic
Liquid is viscous- syringe not dropper
MIXING
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Luting- 1:1
Mix in 30 sec
Consistency- glossy
Working time 1 ¾ min set 3-4 min
• Clean up ASAP with water
• P-zinc oxide
• L- polyacrylic acid
Glass Ionomer
• We have already discussed GI liner. In DMII we
will discuss GI as a Perm restoration or core
build up. Here, we will discuss GI cement, used
for Perm Luting, or as a base.
• Forms- P&L, capsules, 1 paste
• Adv- high strength, low solubility, F,
adheres to moist area, bonds to tooth
• Irritating to tissue
Capsules, Paste, P&L
Comp of Cements
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Varnish- copal
Liner- calcium hydroxide or GI
ZOE
zinc oxide eugenol
ZPO4
zinc oxide orthophosphoricA
Carbox
zinc oxide polyacrylic Acid
GI FAlosilicate glass polyacrylic Acid
The Cronicks