duplicating & wax up
DESCRIPTION
Duplicating and wax up in partial prosthesisTRANSCRIPT
Purpose
Procedure
Material
What is duplicating? What is duplicating?
Duplicating & wax-upDuplicating & wax-up
AdvantagesAdvantages
Preserve the original castPreserve the original cast Eliminating the danger of fracture or Eliminating the danger of fracture or
abrading the surface of the original master abrading the surface of the original master cast cast
Forming the wax or plastic patternForming the wax or plastic pattern The metal framework is cast against the The metal framework is cast against the
surface of refractory castsurface of refractory cast
Duplicating materials & flasksDuplicating materials & flasks
Duplicating materials & flasksDuplicating materials & flasks
Duplicating materials & Duplicating materials & flasks
Duplicating materials & flasksDuplicating materials & flasks
DuplicatingDuplicating
Materials used for Materials used for dduplicating :uplicating :
Duplicating gelsDuplicating gels SiliconesSilicones
Agar Composition
Agar 12-25 %
Borax 0.2 %
Potassium sulfate 1-2 %
Alkyl benzoate 0.1 %
Water 85 %
Plasticizer glycerin
Filler silica , wax , rubber
Bactericidal Agent Thymol , Quaternary ammonium
Coloring / flavoring agent
HysteresisGel Sol
70-100 °
37-50 °
Agar
liquefaction 100 ° 8-12 min
Storage 65 ° 7 days
Chilling 18-21 ° 3-5 min
Agar
Duplicating procedureDuplicating procedure
Duplicating procedureDuplicating procedure
Duplicating procedureDuplicating procedure
Duplicating procedureDuplicating procedure
Duplicating procedureDuplicating procedure
Duplicating procedureDuplicating procedure
Duplicating procedureDuplicating procedure
Duplicating procedureDuplicating procedure
Duplicating procedureDuplicating procedure
Duplicating procedureDuplicating procedure
InvestmentInvestment
Select investments that is compatible Select investments that is compatible
alloys alloys
Investment
Wax pattern shrinkage
Metal shrinkage (~ 1.5-2%)
Wax pattern expansion
Investment expansion• Setting• Hygroscopic• Thermal
ExpansionExpansion Setting ExpansionSetting Expansion
Hygroscopic setting expansion
Thermal Expansion.Thermal Expansion.
““Ideal” Investment:
Expaned to compensate metal shrinkageExpaned to compensate metal shrinkage
not decompose at high temperaturenot decompose at high temperature
Strengthed at various temperatureStrengthed at various temperature
Porous to allow the escape of gasesPorous to allow the escape of gases
Consistent casting temperaturesConsistent casting temperatures
““Ideal” InvestmentIdeal” Investment
Easy to manipulate.Easy to manipulate.
Smooth castings.Smooth castings.
Easy to break out.Easy to break out.
Inexpensive.Inexpensive.
TYPES OF INVESTMENTS
Based on the type of binderBased on the type of binder::
Gypsum-bonded or Calcium-sulfate bondedGypsum-bonded or Calcium-sulfate bonded
Phosphate-bondedPhosphate-bonded
Gypsum-bonded or Calcium-sulfate bondedGypsum-bonded or Calcium-sulfate bonded
CompositionComposition Binder: a-hemihydrate form of gypsum (25-45%)Binder: a-hemihydrate form of gypsum (25-45%)
Ca SO4 ½+3/2 h2o= Ca So4.2H2oCa SO4 ½+3/2 h2o= Ca So4.2H2o
Not to be heated above 700Not to be heated above 700ooC C decomposition decomposition
Phosphate-bonded investmentPhosphate-bonded investment
CompositionComposition::
Filler (refractory) = quartz or cristobalite or both Filler (refractory) = quartz or cristobalite or both (80%)(80%)
Binder = magnesium oxide and acid phosphateBinder = magnesium oxide and acid phosphate
Liquid = colloidal silica suspensionLiquid = colloidal silica suspension
FactorFactor Setting hygroscopic Setting hygroscopic
expansionexpansion Thermal expansionThermal expansion
Water/powder ratio Water/powder ratio increasedincreased
DecreasedDecreased DecreasedDecreased
Time of spatulation Time of spatulation increasedincreased
IncreasedIncreased No effectNo effect
Rate spatulation Rate spatulation increasedincreased
IncreasedIncreased No effectNo effect
Age of investment Age of investment increasedincreased
DecreasedDecreased No effectNo effect
Delay before Delay before immersion increasedimmersion increased
DecreasedDecreased
Water bath Water bath temperature patternstemperature patterns
IncreasedIncreased
DuplicatingDuplicating
DuplicatingDuplicating
Duplicating procedureDuplicating procedure
Refractory castRefractory cast
1
2
3
1-Master cast
2. Refractory cast
3. Master cast
Waxing the frameworkWaxing the framework
Dental waxesDental waxes
Pattern waxPattern waxeses
11..Inlay waxesInlay waxes
3.Baseplate waxes2.Casting waxes
Casting waxCasting wax
The pattern for the metallic framework of RPD.
Casting waxCasting wax
Casting wax : Casting wax : CCompositionomposition
The ingredients are similar to inlay waxes
Casting wax : PropertiesCasting wax : Properties
FlowFlow
Breaking pointBreaking point :: no fractureno fracture
PiPillable and readily adaptableable and readily adaptable
Adapt Adapt accurately accurately to to surface against which it pressed surface against which it pressed
not be brittle on coolingnot be brittle on cooling
VapVappporize, leaving no film orize, leaving no film ratherrather than than ccarbonarbon
Working propertiesWorking properties
Lingual bar waxing
Half-pear-shaped , 6- gauge + 24-gauge sheet wax
Minor connector (guiding plate)Minor connector (guiding plate)
Half round 8-gauge
Minor connectorMinor connector
Round wax 10-gauge
Metal base
24-gauge sheet wax24-gauge sheet wax
RestRest
Half round 8-gauge
Reciprocal armReciprocal arm
Half-round 12 gauge
Half-round 8- gauge
External finish lineExternal finish line
14-gauge round wax
Saddle waxing
Longitudinal pieces12-gauge half round
Saddle waxingSaddle waxing
Buccal loop 18-gauge round wax
External finish lineExternal finish line
14-gauge round wax
Nailhead configurationsNailhead configurations
Round wax 14-gauge
Wrought wire joiningWrought wire joining
Completed wax patternCompleted wax pattern
any questions ?