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DENTAL CASTING

ALLOYDental Material Laboratory

FKG-UPDM(B)


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TERMINOLOGY

Noble metalsbasic for inlay,crown,and

bride,metal ceramic alloyscorrosion

resistance in oral ca!ityc"emical stable#

Precio$s metals

c"emical stability# %emi&recio$s metals#

Base metals non noble elements,

com&onents of dental castin alloy&"ysical

&ro&erties,control of t"e ammo$nt and ty&eof o'idation#


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FOUR NOBLE METALS

%il!er

Gold

Palladi$m

Platin$m


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CLASSIFICATION OF DENTAL

CASTING ALLOYS

lloys ty&e by f$nction

*y&e + soft

*y&e ++ medi$m *y&e +++ "ard

*y&e + e'tra "ard

lloys ty&e by descri&tion

ellow old

."ite old


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CLASSIFICATION BY ADA 1984

/i" Nobel 0/N 1 23 4 $

Noble0N 1 56 4 $

Base Metal0PB7 56 4 $

8L%%+F+8*+9N 9F D:N*L LL9% B

+%90;6# *P: +++ /+G/ %*=:NG*/

2# *P: + :?*= /+G/ %*=:NG*/


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KARAT AND FINENESS

*"e @arat system s&ecifies t"e old

content of an alloy based on &arts of old &er

52 &art of t"e alloy#

:'52 @arat old is &$re ;33 4 old# Finenesst"e $nit t"at describe t"e old

content in noble metal alloys by t"e n$mber

of &arts of old &er ;333 &arts of alloys#

:'&$re ;33 4 old "as a fineness of ;333


7/25

PROPERTIES OF DENTAL

CASTING ALLOYS

Biocom&atibility

8orrosion resistance

*arnis" resistance

llerenic com&onents in castin alloys est"etics

*"ermal &ro&erties

Meltin rane Porcelain bondin

Finis"in of cast metal


8/25

DENTAL CASTING ALLOYS

+ncl$de t"e old and non old#

Noble and base metals alloys f$ll metal and

&artial !enneers#

;#%il!er A Palladi$m lloys

."ite colored&redominantly sil!er in

com&osition#

Palladi$m at least 56 4 %il!er tarnis" resistance

8astin tem&erat$res are in t"e rane of

yellow old alloys


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5# Metal 8eramics lloys

ll t"e alloys "a!e to bond to dental

&orcelain

8oefficients of t"ermal e'&ansion com&atiblewit" dental &orcelain

%olid$s tem&erat$re is s$fficiently "i" to

&ermit t"e a&&lication of low f$sin

&orcelains


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11/25

NOBLE METAL ALLOYS FOR

PORCELAIN BONDING

old-&latin$m-&alladi$m old content

ranin $& to 4

old-&alladi$m-sil!er old based alloys

between >C4 and 4 old, $& to >6 4&alladi$m,55 4 sil!er

old-&alladi$m old content 22-66

4,&alladi$m >6-26 4

&alladi$m-sil!er "i" sil!er le!elsdiscoloration (yellow,reen,or brown)

"i" &alladi$m &alladi$m content $& to

4


12/25

BASE METAL ALLOYS FOR

PORCELAIN BONDING

nic@el-c"romi$mnic@els le!els $& to 3

4,c"romi$m content ;>-55 4 ( small amo$nt

of berylli$m 5 4)

cobalt-c"romi$m

only for remo!abledent$re frame wor@s, contain 66-


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TYPICAL COMPOSITION OF SOME MODERN NOBLE

METAL DENTAL ALLOYS

*y&e + old $ > 4,8$ < 4, ;3 4,Pd 3,6 4

*y&e ++ old $ 4,8$ 4, ;2 4,Pd ; 4

*y&e +++ old $ 6 4,8$ C 4, ;; 4, Pd

>,6 4 *y&e +++ Low old $ 2< 4,8$ 4, >C 4,

Pd < 4


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*y&e +++ sil!er-&alladi$m $ -, 8$ -, 3 4,

Pd 56 4

*y&e + old $ ,6 4 *y&e + low old $ 6< 4,8$ ;2 4, 56 4,

Pd 2 4

*y&e + sil!er-&alladi$m$ ;6 4, 8$ ;2 4,

26 4, Pd 56 4


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PHYSICAL PROPERTIES

1. Type I gold

- melting range 943-960 0 C

- density 16.6 gm/cm 2

- yield strength 103 Mpa

- hardness 0 !"#

- elongation 36 $

2. Type II gold


- density 1%&9 gm/cm 2


- hardness 101 !"#

- elongation 3 $


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># Type III gold


- density 1%&% gm/cm 2

- yield strength 20' Mpa

- hardness 121 !"#

- elongation 39 $

4. Type III lo( gold


- density 12& gm/cm 2


- hardness 13 !"#

- elongation 30 $-


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%. Type III sil)er-palladi*m


- density 10&6 gm/cm 2


- hardness 143 !"#

- elongation 10 $

6. Type I! gold


- density 1%&2 gm/cm 2

- yield strength 2'% Mpa

- hardness 149 !"#

- elongation 3% $-


18/25

'. Type I! lo( gold

- melting range '1-932 0 C


- yield strength 3'2 Mpa

- hardness 16 !"#

- elongation 3 $

. Type I! sil)er -palladi*m



- yield strength %'2 Mpa

- hardness 220 !"#

- elongation 20 $-


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MECHANICAL PROPERTIES

;# 8o-8r % ;3 M&a, *% 3 M&a, :lonation ;,<4, /ardness 2>5 /N, M: 55>,6 M&a';3 <

5# Ni-8r % ,

4, /ardness >33 /N, M: ;5 M&a';3 <

3. Co-Cr-#i % 23 M&a, *% M&a, *% < M&a,:lonation 4, /ardness 5


20/25

CASTING SHRINKAGE

*"e s"rin@ae occ$rs in t"ree staes

;# *"e t"ermal contraction of liE$id metal#

5# *"e contraction of metal in"erent in itsc"ane from liE$id to solid state#

># *"e t"ermal contraction of solid metal#


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REMOVABLE PARTIAL DENTURE

ALLOYS

*y&e + old alloys

8o-8r 34 8r

Ni-8rt"e most often $sed beca$se relati!e

easy of castin and finis"in# 8o-8r-Ni a !ariation on t"e traditional 8o-

8r alloys,Ni is $sed to form strent"enin

&"ases#


22/25

WROUGHT ALLOYS

%*+NL:%% %*::L%

."en ;5->3 4 8r is added to iron#

:lement ot"er t"an iron, carbon, and 8r#

=esintance

tarnis" and corrosion

8r59>

o'ide layer#

*/=:: *P:% 9F %%

;# F:==+*+8 ( 8r ;;,6-5 Ni - 8 3,53 )

5# U%*:N+*+8 ( 8r ;# M=*:N%+*+8 ( 8r ;;,6-; Ni 3-5,6 8 3,;6-

;,53)


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F:==+*+8 %*+NL:%% %*::L%

*"ese alloys desinated by merican +ron and

%teel +nstit$te series 233 %%#

*"is series

martensitic %% Good corrosion resistance

M=*:N%+*+8 %*+NL:%% %*::L%

8orrosion resistance 7

/i" strent" and "ardness

- Used for s$rical and c$ttin instr$ments


24/25

U%*:N+*+8 %*+NL:%% %*::L%

*"e most corrosion resistant alloys

Used for ort"odontic wires,endodontic

instr$ments and crowns in &ediatric dentistry Greater d$ctility

- :ase of weldin and solderin


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SEKIAN

TERIMA KASIH

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