d e n t a l s t u d i o sP r e p a r a t i o n G u i d e : a n t e r i o r premier

a l l - c e r a m i c

But t jo in t mar g in

Footba l l - shapedf in i sh ing bur

Rounded in ter na ll i ne ang les

But t jo in t mar g in1.0 -mm reduct ionat g ing i va l mar g in

1.5 -mm l ingua lcontac t c lear ance

1.5 -mm to 2 .0 -mminc i sa l reduct ion

1.0 -mmto 1.5 -mmfac ia l reduct ion

chamfer mar g in

1.0 -mm 1.5 -mmreduct ion a t

g ing i va l mar g in

1.0 -mm to 1.5 -mml ingua l contac t c lear ance

1.5 -mm to 2 .0 -mminc i sa l reduct ion

1.5 -mmto 2 .0 -mmfac ia l reduct ion

p o rc e l a i n f u s e d t o m e t a l

veneersfull - coverage crowns

Depth cut s o f0 .6 -mm to 0 .8 -mm

1.0-mm to 1 .5 -mminc i sa l reduct ion

contac t po in t

chamfer marg ins : Correct preparation of the chamfer margins interproximally al lows for adequate bulk of porcelain.

a “s l i ce” preparat ion : This technique enables the ceramist to close the space and avoid unnatural l ingual contour s.

i n terprox ima l extens ion : Using the same round-ended diamond bur, the interproximal preparation is extended from the gingival chamfer margin into the proximal space .

i nc i sa l preparat ion : The diamond is angled to el iminate undercuts and establish a butt joint on the l ingual aspect of the preparation. The incisal edge should be

rounded to el iminate sharp l ine angles.

un i form fac ia l preparat ion : A medium-gr it round-ended diamond is used to join the depth cut grooves to establish a uniform preparation and porcelain thickness of at least 1.0-mm.

* All internal l ine angles are rounded and smoothed *

1.0 -mm reduct ionat g ing i va l mar g in

But t jo in t mar g in

1.5 -mm ax ia lreduct ion

1.5 -mm to 2 .0 -mminc i sa l reduct ion

three - unit bridge

maryland bridge1.5 -mm l ingua l c lear ance

2 .0 -mm prox ima l box

Supr a-g ing i va lmar g ins

1.0 -mm to 1.5 -mmrounded shou lder reduct ion

d e n t a l s t u d i o sP r e p a r a t i o n G u i d e : p o s t e r i o r premier

a l l - c e r a m i c

1.5 -mmax ia l reduct ion

A f l a t -ended tapered d iamond buri s u t i l i zed to es tabl i sh a but t jo in t mar g in .

1.0 -mm to 1.5 -mmging iva l mar g in reduct ion

1.5 -mm to 2 .0 -mmocc lusa l reduct ion

p o rc e l a i n f u s e d t o m e t a l

f u l l c a s t

full - coverage crowns three - unit bridge

inlay/onlay bridgeonlay

inlay

rounded in ter na ll i ne ang les

fea ther-edge orchamfer mar g in

1.0 -mm bucca l andl ingua l reduct ion

1.0 -mm to 1.5 -mm occ lusa l reduct ion

Porce la injunc t ion

mar g in des i gn

No sharpcorners

Bucca l L ingua l

Meta lmar g in des i gn

orce la injunc t ion

mar g in des i gn

No sharpcorners

ucca l L ingua l

Mmar g in des i gn

2.0-mmocclusal reduction

1 .0 -mm to 1 .5 -mmwide g ing i va l f loor

Rounded in ter na ll i ne ang les

1 .5 -mm to 2 .0 -mm i s thmus w idth

1 .5 -mmdepth

at i s thmus

But t jo in t mar g in

1 .5 -mm to 2 .0 -mm i s thmus w idth

Rounded in ter na ll i ne ang les

But t jo in t mar g in

1 .0 -mm to 1 .5 -mmwide g ing i va l f loor

1 .0 -mm reduct ionat the g ing i va l mar g in

But t jo in t mar g in

1 .5 -mm to 2 .0 -mmocc lusa l reduct ion

1 .5 -mm ax ia l reduct ion

Premolar in l ay prepar a t ion( 1 .5 -mm depth )

Mola r on lay prepar a t ion( 2 .0 -mm cuspa l reduct ion )

Edentu lous space

2 .0 -mm cuspa l reduct ion