???, dental stone, ???, ????? ?? ? ????

1
???, dental stone, ???, ????? ?? ? ????

• ???? ???
• ??? ???

2
Reversible hydrocolloid impression material(agar)

• ADA specification
• 10 ??? ?? 30? ?? load? ??
• ?????? 1.5 ??(? 1? ????)
• Remove with a sudden motion
• Remove with a quick jerk
• Dimensional stability X (imbibition, syneresis)
• ?? pouring
• If not, 100 humidity or 2 k2SO4,solution?
• ??

3
Irreversible impression material (alginate)

• ADA specification
• 10 compressed? ??? 30? ??
• ????? 3 ??(?? 1.5)
• ???? ?
• -testing ? ??? ????
• -removal ?? ?? distortion ?? ?????
• -compression?? ??? ?????
• -W/P ratio ?
• ?? pouring
• If not, 100 humidity ??

4

• Impression compound
• ?????? ?? ??(25C)? ?? ? 0.30.4 shrinkage
• ?ZOE ??? final impression
• Zinc Oxide Eugenol Impression Paste
• (ZOP)
• 30? ?? ? 0.1 ??? shrinkage
• 24?? ???? ? ??? dimensional
• change X

5
Elastomeric impression material

• Polysulfide rubber(mercaptan rubber)
• Silicone rubber
• -addition type
• -condensation type
• Polyether rubber

6
type polysulfide Condensation silicone Addition silicone polyether
Shrinkage. 24 hours() 0.25 0.6 0.05 0.10
stability 1 hr Pour as soon as possible days 1 hr
product Water Ethyl alcohol ?? X X

• Dimensional stability
• condensation silicone ltpolysulfide ltpolyether
• ltaddition silicone

7
Inlay casting wax

• Thermal contraction
• 0.035 /C
• ?indirect technique??? ?? X

8
Inlay casting wax

• Reduction of distortion
• ADA specification No.4? ??? wax? ??
• Dry heat, ??? ???? ??
• ??? ???? ??? ??? ?? ? ???
• Wax pattern? die?? ??? ? ????? ?? ?
• ?? ? wax pattern? ??? ? ?? ??
• Full crown? ?? die? liquid wax? dip repeatedly
• Silk cloth? final polishing

9
Gypsum

• Application
• -cast(model) ???
• -die
• -impression material
• -binding agent of investment

10
??
?? ????????(ADA)
Type I ??? ??(?? ??) 0.07 (?? 0.06)
Type II Plaster (white) 0.3
Type III Stone (yellow) 0.2
Type IV Improved stone 0.1
Type V Colloidal silica ??(???), ???? ??? silica ?? ??? ?? ?, ???? Colloidal silica ??(???), ???? ??? silica ?? ??? ?? ?, ????
11

• Control of setting expansion
• 1)immersion in water
• (hygroscopic setting expansion)
• ???? ?, ???? ??? ??
• ??? ??? ?? ??? ??
• 2) ???? ??? ????? ?
• 3)Mixing time ?????? ?
• 4)W/P ratio ?????? ?

12

• ???? ???
• -accelerators
• 20 ??? NaCl, k2SO4,,inorganic salt
• 12 ??? Na2SO4
• -retarder
• borax, borate, citrate, 20 ??? NaCl,
• 12 ??? Na2SO4,,zinc acetate,
• colloid

13
Investment

• ??
• Gypsum-bonded investment
• Phosphate-bonded investment
• Silica-bonded investment

14

• ADA specification No.2 for casting investments
  for dental gold alloy
• 1.Type I investment
• inlay or crown casting (thermal expansion)
• 2.Type II investment
• inlay or crown casting
• (hygroscopic expansion)
• 3.Type III investment
• construction of partial denture with gold
  alloys (thermal expansion)

15
Gypsum bonded investment

• ????
• -??? ?? ??
• -but, ?? ?? wax pattern ??
• - ADA specification No.2??? type I? ?? 0.5
  ??? ??
• (?? modern investment? 0.4 ??)
• -low W/P ratio
• ? mold? effective setting expansion ??

16

• ????
• -???? ????? ? ??? ??? ?? ?? ??? ?? ????? ??
  ????? ?? ?? ?? ?? ??? ??? ??
• ??? ?????? 6? ??
• - ADA specification No.2 ? type II investment
• 1.2 2.2

17
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18
????? ??? ?? ???

• Effect of composition
• -silica ?, silica? particle size ?
• Effect of the W/P ratio
• Effect of spatulation
• Shelf life of the investment
• Effect of time of immersion
• Effect of confinement
• Effect of the amount of added water

19

• ???
• -cristobalite? ??? investment? quartz? ???
  investment?? ? ??, ? ?? ??
• -ADA specification No.2
• type I investment 12
• type II investment-00.6
• -W/P ratio ? ? ????

20

• ?? ??? ??? ??? ???? ?????

21

• ??? ???? ?? ??? ??? ??? ??

???? ????? ???? ???
???? ?? ??
???? ? ?? ??
???? ? ?? ??
???? ??? ? ?? ??
????? ??? ???? ? ??
???? ? ??
Wax? ?? ?? ?? ?? ??
Sprue? ?? ?? ?? ?? ??
22
Phosphate bonded investment

• ????? ???
• -?? ? ??? ??
• -??? colloidal silica suspension? ??? ?? ??? ???
  ??
• -????? ?? ? ? ?? ? ???
• colloidal silica suspension
• colloidal silica suspension water x
  100
• -?????? ?? ?? 200-400C?? ??
• but, colloidal silica suspension?? ?? ? ?? ??
  ??

23
Casting gold alloys
Type Noble metal (Au Pt) color ??
Type I 83 yellow Small inlay
Type II 78 Light yellow Inlay crown
Type III 78 Light yellow Cr Br
Type IV 75 white RPD, long Br, Clasp
24

• ????? ???? ??? ??

25
???????? ?????

• ?? ? ????

26

• ??? ??

27

• Linear casting shrinkage

Metal Casting shrinkage()
Gold(100) 1.67
22-k alloy 1.50
Type I 1.56
Type II 1.37
Type III 1.42
28
Asbestos liner

• Liner? ??? ???? ???? ???? ?? ? ? semihygroscopic
  expansion? ?? ? ?? normal setting expansion? ??
• 1mm ???? ??? liner? ???
• Liner? ring?? 3mm ?? ??
• longitudinal expansion ?
• ?uniform expansion? ??

29
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30
Control of the shrinkage compensation

• Restoration type? ?? ???? shrinkage ???
• MOD inlay, full Cr gt occlusal inlay
• Configuration of pattern
• ?? ??? ??? ???? ?? ? ??
• Asbestos liner? ??? ??
• Wax pattern? ???? sprue former? ??
• ex) MOD inlay
• occlusal metal ring? ?? mesiodistal expansion
  ??
• proximal - mesiodistal expansion? ring? open
  end ???? ?? ???

31

• W/P ratio ?(thick mix)
• ? ?? ????? ?
• Hygroscopic expansion? ??
• W/P ratio, ?? ??, ?? ?
• Wax type? ?? ???
• soft wax gt hard wax
• Burn-out temperature ?? ????
• Hygroscopic expansion ? ?? ?? ?
• ? ????

32
?? ??????

• AROMA FINE DF III NORMAL SET
• HI-kosetone(yellow stone)
• GC FUJIROCK(brown stone)
• New Plastone(white stone)
• PERMLASTIC polysulfide
• Flexitime vinyl polysiloxane
• Permadyne polyether

33

• AROMA FINE DF III NORMAL SET
• -alginate
• -????? 2.2

34

• HI-kosetone(yellow stone)
• -improved dental stone
• GC FUJIROCK(brown stone)
• - improved dental stone
• -setting expansion 0.08
• New Plastone(white stone)
• - setting expansion 0.25

35

• PERMLASTIC

Light bodied Regular bodied Heavy bodied
Type Type 3 Type 2 Type 1
Max Strain in Compression() 15.2 12.9 7.8
Recovery from deformation () 97.8 97.2 98.7
Linear dimensional change() 0.40 0.35 0.45
36

• Flexitime

Easy putty Heavy putty Mono Phase Correct flow
Max Strain in Compression() 1.8 1.6 2.6 4.6
Recovery from deformation() 99.7 99.0 98.8 99.6
Linear dimensional change() 0.20 0.18 0.20 0.11
37

• Permadyne

Heavy-bodied consistency Light-bodied consistency
Max Strain in Compression() 2.8 3.0
Recovery from deformation() 98.5 99.3
Linear dimensional change() -0.1 -0.1
38

• Kerr inlay casting waxes

color Type Approximate melting point(C) Residue on lgnition()
Blue Regular 71 lt0.1
Blue Type 2 74 lt0.1
Green Type 2 75 lt0.1
Ivory Regular 72 lt0.1
39
Gold alloy

• AGIS-IN88
• inay

• Physical properties

Melting Temp(C) 1,0201,030
Casting Temp(C) 1,1201,130
Tensile Strength(Mpa) 265
Yeild Strength(Mpa) 100
Vickers hardness(VHN) 70
Density(g/cm3) 16.83
Elongation() 41.72
Softening Heat Treatment(C) 700/10
AU PT Ag
88 0.1 9.1
40

• AGIS-A(A type)
• Cr, CR BR

• Physical properties

Melting Temp(C) 930965
Casting Temp(C) 1,0101,050
Tensile Strength(Mpa) 370
Yeild Strength(Mpa) 245
Vickers hardness(VHN) 170
Density(g/cm3) 13.1
Elongation() 34
Softening Heat Treatment(C) 700/10
AU PD ??
48.3 4.2 BAL
41

• AGIS-REX(SA type)

• Physical properties

Melting Temp(C) 920958
Casting Temp(C) 1,0201,060
Tensile Strength(Mpa) 425
Yeild Strength(Mpa) 270
Vickers hardness(VHN) 150
Density(g/cm3) 14.38
Elongation() 42
Softening Heat Treatment(C) 780/10
AU PD ??
62.8 3 BAL
42

• NEO76(Pt type)

• Physical properties

Melting Temp(C) 948955
Casting Temp(C) 1,0001,060
Tensile Strength(Mpa) 440
Yeild Strength(Mpa) 290
Vickers hardness(VHN) 135
Density(g/cm3) 15.59
Elongation() 49
Softening Heat Treatment(C/?) 780/10
AU PT PD
76 1 2
43

• CERANUM82(PFG)

• Physical properties

Melting Temp(C) 1,1321,139
Casting Temp(C) 1,2001,240
Tensile Strength(Mpa) 490
Yeild Strength(Mpa) 345
Vickers hardness(VHN) 205
Density(g/cm3) 17.9
Elongation() 11.3
Oxidation Heat Treatment(C/?) 980/10
Porcelain Bonding strength(Mpa) 41.3
C.T.E(ppm/C) 13.33
AU PT PD
82 6.5 3.8
44

• ???????????????F-1
• -gypsum bonded investment
• -inlay or crown
• -setting expansion 0.6
• -thermal expansion 1.3

45

• CB-30 Crown Bridge Investment
• -phosphate bonded investment
• -Cr BR, porcelain
• -setting expansion 0.5
• -thermal expansion 1.5

46
??? ????????!!!