An inlay may cap none, or may cap all but one cusp. Sturdevant’s 4th ed. page579 Inlays may be used as single-tooth restorations for proximo-occlusal or gingival lesions with minimal to moderate extensions Shillingburg page 1 An inlay may be defined as a restoration which has been constructed out of mouth from gold, porcelain, or other material & then cemented into the prepared cavity of a tooth. William McGehee pg410

1. INLAY
GUIDED BY:
DR.RAHUL MARIA
PRESENTED BY:
DR. ANUBHUTI
MDS
Conservative Dentistry & Endodontics

2. CONTENTS
Definition
Indications
Contraindications
Advantages /Merits over (direct restorations/others)
Disadvantages/De-Merits over (direct restorations/others)
Armamentarium
Basic concept of cavity design
Difference between amalgam & inlay Preparation
anusavice 11th edition 2

3. Dr. Phil brook in 1897,was the first to introduce
Inlay in dentistry who gave the concept of forming an
investment around a wax pattern, eliminating the
wax, and filling the resultant mold with a gold alloy.
In 1907 Taggart changed the practice of restorative
dentistry by introducing his technique for cast gold
dental restorations
3
INTRODUCTION
Charbeneau page no: 349

4. METERIALS FOR CAST RESTORATIONS
valuble in restorations to rebuild most or entire occlusal surface.
High tensile and Compressive forces
Advantage
Casting alloys used
4
Charbeneau page no: 350

5. FOUR DISTINCT GROUPS OF ALLOYS ARE USED
CURRENTLY
High gold
alloys
Low-gold
alloys
Pallidium-
silver
alloys
Base
Metal
Alloys
5

6. ACCORDING TO STURDEVANT THERE ARE 4 DISTINCT
GROUPS OF ALLOYS.
The traditional
high gold
alloys.
Low gold
alloys.
Palladium-
silver alloys
Base metal
alloys.
6

7. ACCORDING TO MARZOUK:
Class-I:
Gold and
platinum
group
based
alloys.
Class-II:
Low gold
alloys
(gold
content <
50%).
Class-III:
Non-gold
palladium
based
alloys.
Class-IV:
Nickel-
chromium
based
alloys.
Castable
moldable
ceramics
anusavice 11th edition 7

8. ACCORDING TO ADA SPECIFICATION NO.5:
Type-I (Soft): For restorations subject to very slight stress such as inlays.
Type-II (Medium): For restorations subject to moderate stress such as onlays.
Type-III (Hard): For high-stress situations, including onlays, crowns, thick veneer crowns
and short-span fixed partial dentures.
Type-IV (Extra hard): For extremely high stress states, such as endodontic posts and cores,
thin veneer crowns, long span fixed partial dentures and removable partial dentures.
8

9. An inlay may cap none, or may cap all but one cusp.
Sturdevant’s 4th ed. page579
Inlays may be used as single-tooth restorations for
proximo-occlusal or gingival lesions with minimal
to moderate extensions
Shillingburg page 1
An inlay may be defined as a restoration which has
been constructed out of mouth from gold,
porcelain, or other material & then cemented into
the prepared cavity of a tooth.
William McGehee pg410
DEFINITIONS

10. A fixed intra-coronal restoration, made
outside of a tooth to correspond to the
form of the prepared cavity, which is then
luted into the tooth.
GPT 2005

11. A cavity’s width does not
exceed one-third the
intercuspal distance
Strong, self-resistant cusps
remain
minimum or no occlusal
facets and if present, are
confined to the occlusal
surfaces
The tooth is not to be used
as a abutment for a fixed or
removable prosthesis
Occlusal or occluding
surfaces are not to be
changed by the restorative
procedure.
INDICATIONS
Marzuk’s page no 323
11

12. Occlusal
disharmony
CONTRA INDICATIONS
Sturdevant’s 4th edition & Rosensteil page no:309
anusavice 11th edition 12

13. ADVANTAGES
Excellent
mechanical
properties.
Low creep &
corrosion
No tooth
discoloration.
Control of
contours &
contacts
Sturdevant & Rosensteil page no: 309anusavice 11th edition 13

14. In the
restoration of a
small carious
lesion an inlay is
not very
conservative.
Rely on the bulk
of the buccal &
lingual cusps for
resistance &
retention form.
(wedge the
cusps)
Number of
appointments
Temporary
Necessity for a
cementing
medium.
DISADVANTAGES
Sturdevant & Rosensteil page no: 309 14

15. Burs :
TF -21
• FCR-12EF
• FO-21F
• TF-S31
• TF-41CA
• TF-11CA
• TC-S21
• TF-S41
Chisel Hatchet
BLADE should
be SHARP &
BROAD
Gingival
marginal
trimmers
BLADE should
be SHARP &
BROAD
Excavaters
Rosensteil page no: 310
ARMAMENTARIUM
anusavice 11th edition 15

16. SELECTION OF PATIENT
Contact
point
Height of
the tooth
IOPAR
16
OVOID
(narrow)
MORE
PULP
CHAMBER

17. VARIATION IN
PROXIMAL
MARGIN DESIGN
BEVELSINLAY TAPER
BASIC CONCEPTS OF CAVITY DESIGN
Charbeneau page no:351,352,353 17

18. INLAY TAPER
In extracoronal preparation walls must converge from the cervical to the
occlusal surface. This is the concept Of taper.
Taper permits an unobstructed removal of the wax pattern & seating of the
subsequent casting.
The taper is 2-5 degree from the path of preparation
Each wall should make a right angle or slightly obtuse angle with the pulpal
floor.
Longer preparations require taper in higher range, short preparations in the
lower range.
Charbeneau page no:351
18

19.  Extension of opposing walls, which
diverge toward the occlusal form a
convergent angle ‘b’. A bisection of
this angle positions the “line of
draw” which is perpendicular to
the pulpal floor.
EXTRACORONAL TAPER
Charbeneau page no:352
Angle ‘a’ defines the relation of the lateral cutting
surface of the bur with the ‘line of draw’

20. EXTRACORONAL TAPER
Extension of opposing walls,
which converge towards the
occlusal maxillary tooth.
Charbeneau page no:352

21. Bevels are the flexible
extensions of a cavity
preparation, allowing the
inclusion of surface defects,
supplementary grooves, or
other areas on the tooth
surface.
Beveling of enamel margins
serve the following purposes-
Obtuse -angled tooth structure
i.e. the strongest configuration
and acute-angled marginal alloy
i.e. burnishable. Thus makes it
possible to decrease the cement
line.
A lap, sliding fit is
produced at
gingival margin.
It results in 30-
degree metal that is
burnishable.
Weak enamel
is removed.
BEVEL
Charbeneau page no:352

22. Properly directed gingival
bevel resulting in 30 degree
marginal metal
Failing to bevel gingival
margin resulting in
undermined rods and
difficulty in burnishing.

23.  Mesial bevel directed
correctly to result in 40
degree marginal metal.
 Unbeveled mesial margin
is incorrect because it
results both in weak
enamel margin and
unburnished marginal
metal.

24. Partial bevel
Involves the part
of the enamel
wall, not
exceeding 2/3rd
of its dimensions.
Not used in cast
restorations
Used to trim
weak enamel
rods from margin
peripheries
Short bevel
Includes the
entire enamel
wall but not
dentin
Long bevel
Includes all of the
enamel wall & up
to one half of the
dentinal wall.
Advantage:
preserves the
internal boxed up
resistance &
retention features
of the preparation
Full bevel
Includes all of the
dentinal & enamel
walls .
Disadvantage:
deprives the
preparations
internal resistance
& retention form
Counter bevel
Given opposite to
an axial wall, on the
facial or lingual
surface with the
gingival inclination
facially or lingually.
Used for the
capping of cusps
to protect &
support them `
Hollow ground
(concave)
bevel
Prepared in concave
form. It allows
more space for cast
material bulk
TYPES OF BEVEL
24

25. Design of proximal
margins will vary with:
• The extent of tissue loss
• The location of that loss
• Tooth form
• The positional relationship
with adjacent teeth
• Need for retention form
• convenience
BOX
SLICE
AUXILLARY
SLICE
MODIFIED
FLARE

26. PRINCIPLES OF CAVITY DESIGN
External
outline
form
Internal
outline
form
Resistance
& retention
form
Removing
carious
dentin
Convenience
form
Finishing
enamel
walls and
margins

30. Straight lines and smooth
flowing curves avoiding
nay sharp angles.

31. The occlusal surfaces of maxillary molars
and mandibular first bicuspids are usually
divided into mesial and distal segments by
oblique and transverse ridges
respectively .
When this ridge is not undermined by
caries or crossed by retentive fissure, it
should be allowed to remain intact and not
be included in the prepared cavity.

33. Finishing line should be
extended on the occlusal to
include retentive fissures, and on
to the proximal cervical areas

35. The pulpal floor and axial wall
of the gold inlay preparation
must be based in dentin

36. • In all instances the
taper should be
visible to the eye.
Taper required varies with the ‘depth or length’
of the preparation from occlusal to cervical aspect

37. Line angles should be
well defined
Flare should be from
100-110 degree
Axiopulpal line angle
is rounded

38. In shallow or
short cavities
taper should
be minimal
Enhance the
resistance and
retention form
In deep or
long cavities
More taper is
required
Facilitate the
seating of the
restoration

40. SILVER AMALGAM CLASS II INLAY
Outline form narrow, walls converge occlusally wide, walls diverge occlusally
Cavity width 1/4th of intercuspal dist. 1/3rdof intercuspal dist.
Cavosurface angle 90, butt joint 130-140, lap sliding fit joint
Gingival bevel 15-20 20-30
Undercuts improve retention No undercuts should be present
Minimum Clearance 0.5 from adjacent teeth More clearance needed
Secondary retention grooves, slots, pins grooves, slots, internal boxes,
skirts, collars & reverse bevel
Internal line angle is rounded is well defined
Proximal walls provided with primary flares provided with primary &
secondary flares
Reverse curve present in proximal outline Not provided
anusavice 11th edition 40

41. INLAY WAX
anusavice 11th edition 41

42. TYPES OF INLAY WAX (ADA SP. NO. 4)
Type
Type I – medium
wax – direct
technique
Type II – soft wax –
indirect technique
anusavice 11th edition 42

43. INLAY WAX
MEDIUM
INLAY WAX
SOFT
Excellent plasticity
High modelling ability,
low shrinkage
Burns out without
residues
Precise modellation &
Smooth castings
High stability after
hardening
Low shrinkage
Burns out without leaving
residues
Precise modellation &
Smooth casting

44. Paraffin wax
Ceresin
Gum dammar
Carnuaba wax
Candelilla wax
COMPOSITION
anusavice 11th edition 44

45. Gray
Red
Violet
Green
Blue
COLOUR
anusavice 11th edition 45

46. When softened, the wax
should be uniform.
Color should contrast with the
die or tooth.
No flakiness.
No chipping.
Completely vaporize during
burnout.
Completely rigid &
dimensionally stable at all time
PROPERTIES
anusavice 11th edition 46

47. SELECTION OF PATIENT
Contact
point
Height of
the tooth
IOPAR
47
OVOID
(narrow)
MORE
PULP
CHAMBER

48. Impression
technique
Direct
Method
Open Method
Wax pattern
prepared with a
matrix band
Closed Method
Wax pattern
prepared without
a matrix band
Indirect
Method
anusavice 11th
edition
48

49. 49
DIRECT TECHNIQUE
The internal surface
of the band are lightly
lubricated with a
separating medium.
Retainer,band and
wedge is applied
Finger pressure is
maintained while
the wax is cooled
and hardened
Textbook of endodontics by Vimal sikri ,page no 266

50. 50
The bulk of excess
wax is then trimmed.
Matrix Retainer is
loosened and
removed
Wax is held firmly
in place and band is
removed
Textbook of endodontics by Vimal sikri ,page no 267

51. THE PATTERN IS CAREFULLY INSPECTED FOR:
Sharp internal details
Good reproduction of the
cavosurface and gingival
margins
The gingival flash, if any, is
removed with a sharp scalpel
51Textbook of endodontics by Vimal sikri ,page no 266

52. 52
The pattern is
again seated in
the cavity .
Pattern is then
carved with help of
a plastic instrument
The occlusal surface
may be polished by
rubbing a wet
pledget of cotton
(over the fame) over
the area.
Textbook of endodontics by Vimal sikri ,page no 267

53.  Wax pattern is made on the die.
 Type -2 soft wax.
 More commonly used technique
IN DIRECT TECHNIQUE

54. INDIRECT TECHNIQUE
The model may not be the exact
replica of the tooth.
Time consuming
procedure.
DIRECT TECHNIQUE
Great skill &
patience is
required
Greater
tendency for
wax pattern to
get distorted.
Indirect
vision is
required.
Discrepancies at
the gingival margin
is difficult to detect
If the casting fails
patient has to be
recalled.
DISADVANTAGES

55. The mold channel through
which molten metal or
ceramic flows into the mold
cavity
SPRUE
anusavice 11th edition page no:320

56. PURPOSE:
 To form a mount for the wax
pattern & fix the pattern in space so
a mold can be made.
 To create a channel for elimination
of wax during burn out.
 To form channel for ingress of
molten alloy .
 To compensate for alloy shrinkage
during solidification
anusavice 11th edition page no:321

57. Wax Resin Metal
57
Burnable and so do not
need to be mechanically
removed
Lack
rigidity
Textbook of endodontics by Vimal sikri ,page no 269

58.  Its approximately the same size as the
thickest area of the wax pattern.
 If the pattern is small, the sprue former
must also be small, because attaching a
large sprue former to a thin , delicate
pattern could cause DISTORTION.
 If the sprue former diameter is too small,
( suck back porosity) RESERVOIR
SPRUES are used.
SPRUE DIAMETER
anusavice 11th edition page no:321

59. SUGGESTED SPRUE FORMER DIAMETER
Gauge no. Diameter(cm)
06 0.4115
08 0.3264
10 0.2588
12 0.2053
14 0.1628
16 0.1291
18 0.1024
Textbook of endodontics by Vimal sikri ,page no 270

60. Ideal position is the point of greatest
bulk in the pattern to avoid distorting
thin areas of wax during attachment to
the pattern & to permit complete flow of
the alloy into the mold cavity.
SPRUE POSITION
Anusavice 11th edition page no:320, Textbook of endodontics by Vimal sikri ,page no 270
Minimise the effect of released
residual stresses by the heat of
attaching the sprue
Thinner cross section of the mold will
be filled completely
The melt will always be fluid enough
available untill all lesser dimensions
sections are adequately filled

61. Sprue former should be attached to the
portion of pattern with the largest cross-
sectional areas. Its best for the molten
metal to flow from a thick section to
surrounding thing areas.
SPRUE ATTACHMENT
anusavice 11th edition page no:320

62.  It should be directed away from any
thin or delicate parts of the pattern ,
because the molten metal may abrade
or fracture investment in this area &
result in casting failure.
 Sprue former should not be attached
at a right angle to a broad surface, it
will lead to turbulence & severe
porosity.(45degree)
ANGULATION OF THE
SPRUE
anusavice 11th edition page no:321, Textbook of endodontics by Vimal sikri ,page no 270

63. SPRUE LENGTH
Wax pattern is kept 6.5 mm of
the end of the ring for gypsum
bonded investment and 3.25 for
phosphate bonded investment
Philip's 11th edition page no:320, Textbook of endodontics by Vimal sikri ,page no 269
The length of the sprue former depends
upon the length of the casting ring .

64. Very short sprue:
Molten alloy may
blast through
investment .
Very long sprue :
Gases may not escape rapidly enough to
allow metal to fill the mold space .
Sprue solidifies first leading to casting
shrinkage and POROSITY
Textbook of endodontics by Vimal sikri ,page no 270

65. RESERVOIR
Reservoir is a small amount of additional
wax which is added to the sprue former
near the junction of wax pattern
It prevents localized shrinkage porosity
as the alloy in this part solidifies last after
the solidification of metal in mold
Philip's 11th edition page no:320

66. CRUCIBLE FORMER
 The sprue is attached to a crucible former,
usually made of rubber, which constitutes
the base of the casting ring during investing.
 The exact shape of the crucible former
depends on the type of casting machine
used.
 With most modern machines, the crucible
former is tall to allow use of a short sprue
and allow the pattern to be positioned near
the end of the casting ring.
anusavice 11th edition page no:321Textbook of endodontics by Vimal sikri ,page no 271

67. VENTING
• Small auxiliary sprue/vents are applied to thin wax pattern to
improve the quality of casting. Usually 18- gauges sprues are
used. It is indicated with extremely thin/thick casting to
produce nonporous castings.

68. •They help in escape of gases during casting and ensure
beginning of solidification in critical areas by acting as a
heat sink.
•It is attached to the wax pattern directly opposite to
larger sprue former.

69. The casting ring serves as a container for the investment
while it sets & restricts setting expansion of the mold.
Metal used should be non-corrodible, hard and with a
thermal expansion similar to the investment used
Stainless steel is the most acceptable rings
Average dimensions are 29mm in diameter and 38mm
in height
CASTING RING & LINER
Textbook of endodontics by Vimal sikri ,page no 271

70. • They are available as---
1) Shapes - Round
- Oval
2) Complete rings
I) - Rigid
- Metal (stainless steel) - Plastic
II) Flexible - Rubber
3) Split rings
I) metal
II) plastic

71. CASTING LINER
In order to allow more uniform
setting and hygroscopic
expansion of the investment a
liner is placed inside the ring
Philip's 11th edition page no:323
It becomes easier to remove the
investment and casting from the ring, if a
liner is used

72. Results in distortion of the casting.
Expand towards the center of the mold
It will not be able to expand
outward(because of the resisting action of
the walls of the ring)
Provide buffer of pliable material against
which the investment is in direct contact
with the walls of the mold
NEED FOR THE LINER????
anusavice 11th edition page no:321 , Textbook of endodontics by Vimal sikri ,page no 271

73. Casting
liner
Asbestos
liner
Non-asbestos
liner
Ceramic
liner
Cellulose
liner
Philip's 11th edition page no:323 , Textbook of endodontics by Vimal sikri ,page no 272
73
carcinogenic potential
makes it a biohazard.

74. anusavice 11th edition 74

75. FUNCTIONS OF A LINER
Philip's 11th edition page no:323
Textbook of endodontics by Vimal sikri ,page no 271

76. Thickness – not less than 1mm
Philip's 11th edition page no:320, Textbook of endodontics by Vimal sikri ,page no 271
76

77. Philip's 11th edition page no:320, Textbook of endodontics by Vimal sikri ,page no 271 77

78. SURFACE TREATMENT OF COMPLETED WAX PATTERN
Wax pattern should be cleaned of any
debris, grease, oils and separating
medium.
A commercial wax pattern cleaner or a
diluted synthetic detergent is used.
Any excess liquid is shaken off, and the
pattern is left to air dry while the
investment is being preparedAnusavice 11th edition PAGE NO :324, Textbook of endodontics by Vimal sikri ,page no 271 78

79. anusavice 11th edition 79
INVESTMENT PROCEDURE

80. INVESTMENT MATERIAL
Gypsum-bonded
investment
Phosphate bonded
investment
Ethyl-silicate bonded
investment
80Philip's 11th edition page no:320
REFRACTORY BINDER MODIFIERS

81. • Investment can be described as a ceramic material that is
suitable for forming a mold into which a metal or alloy is cast.
• Craig 12th ed 324
81

83. 1. Strudevants 4th edition
2. Marzouk
3. Charbeneau
4. G.H. Mount
5. Mc Ghee
6. Shillingburg 3rd edition
7. Rosenstiel 4th edition
REFERENCES