Partial veneer crown

1. THE PARTIAL VENEER
CROWN , INLAY AND
ONLAY

2. INTRODUCTION
. Partial veneer crowns generally include all tooth surfaces
except the buccal or labial wall in the preparation.
Therefore, it is more conservative than a complete crown,
In addtion Gingival health near a partial coverage crown is
protected by the supragingival margin
(Kahn AE. J Prosthet Dent 1960 )(Silness J. 1970)
a tooth with a full coverage crown is about 2.5 times as likely
to have a pulpal problem as one with a partial coverage
crown. (Felton D. 1989)
Ref. shilingburg fourth edition pg 388

3. DEFINITIONS :
partial-coverage crown : an artificial replacement
that restores missing tooth structure by surrounding
part of the remaining structure with a material such
as cast metal alloy, ceramics, or resin; it is retained
by mechanical or adhesive means
Ref ( The glossary of prosthodontics, ninth adition ) pg 66,

4. Inlay : a fixed intracoronal restoration; a dental
restoration made outside of a tooth to correspond
to the form of the prepared cavity, which is then
luted into the tooth
Onlay : a partial-coverage restoration that restores
one or more cusps and adjoining occlusal surfaces
or the entire occlusal surface and is retained by
mechanical or adhesive means
Ref ( The glossary of prosthodontics, ninth adition ) pg 49,63

5. PARTIAL VENEER CROWN
- (2) anterior:
- (1) posterior:
-pinledge preparation
-maxillary canin 34
crown
-maxillary central incisor
pinledge
- maxillary premolar
and molar 34 crown
-mandibular premolar
-modified 34 crown
- reverse 3/4 crown
- 78 crown
-proximal half crown

6. . INDICATIONS
- posterior:
-1. Tooth have lost moderate amounts of tooth
structure if buccal wall is intact
2. retainer for an FDP
3. if alteration of the occlusal surface is needed
Anterior :
1.retaining damaged teeth
2. . retainer for an FDP
3. splint teeth

7. . CONTRAINDICATIONS:
Posterior:
1. short crown
2.extensive caries and periodontal diseases
3.extensive destructions
4. poor alingnment ( partial veneer crowns prepared at parallel axial walls )
5. proximally bulbous teeth
6. thin teeth (tooth have a thin bacculingual diamention )
Need making proximal grooves  on these teeth will leave unsupported
enamel
Anterior:
1. short crown
2.extensive caries and periodontal diseases
3.extensive destructions
4. cervical caries
5. thin teeth

8. . ADVANTAGES:
1. conservation of tooth structure
2. easy access to margins (supraGingival )
3. less gingival involvement the with complete cast
crown
4. easy verification of seating ( direct visibility )
5. easy escape of cement and good seating
6. If an electric pulp test ever needs to be
conducted on the tooth, a portion of enamel is
unveneered and accessible ( Ho G. Lecture notes. Los
Angeles: University of Southern California School of Dentistry,
1959)

9. DISADVANTAGES:
1- less retentive than complete cast crown
Lorey RE, Myers GE. The retentive qualities of bridge retainers. J Am Dent
Assoc 1968
2. limited adjustment of path of withdrawal
3. some display of metal

10. . PREPARATION :
- (1) posterior:
(1-1 )- maxillary premolar and molar 34 crown
(1-2)- mandibular premolar modified 34 crown
(1-3) – reverse 3/4 crown
(1-4)- 78 crown
(1-5 ) -proximal half crown
- (2) anterior:
(2-1)- maxillary canin 34 crown
(2-2)- maxillary central incisor pinledge

11. (1-1) maxillary premolar 34 crown
Ref .(contemporary pg244)
1 - occlusal surface preparation :
A- Depth grooves :
- - pinholes in central groove (misial , distal pits )
Depth of : 0.8 mm on nonfunctional cusps, 1.3 mm on
functional cusp
Use : fissure carbide or diamond parallel

12. - please grooves on (misial , distal marginal ridge )
- grooves on ( the lingual incline of the buccal cusp,
buccal incline of lingual cusp)
Use : tapered, round-ended
Diamond

13. B. occlusal reduction :
connecting between grooves 
wide bevel at tip of the cusp Depth:
of 1mm ( on nonfunctional cusp )
1.5mm (functional cusp)
- Assess the amount of occlusal clearance in
maximum intercuspation

14. :
2 .AXIAL PREPARATION
-DEPTH GROOVES FOR AXIAL REDUCTION
-AXIAL REDUCTION :
are prepared in the center of the lingual
surface and in the
Mesiolingual and distolingual transitional line
angles , 
parallel the long axis of the tooth
Depth of : 0.5 mm
Use : tapered, round-ended -
Diamond
Axial reduction: 
Chamfer margin finishing
(0.5 mm supraginival )

15. 3- Proximal preparation
. break proximal occlusal contact
Use : needlepoint diamond
. prepare proximal axial walls
Use : tapered, round-ended
Diamond
(Chamfer margin finishing)

16. -. proximal grooves :
The groove need not be deeper than 1 mm at its cervical end
- placed as far as facially as possible
- ( buccal half of proximal surface) 
Use : carbide bur no. 171 (0.5mm)
Depth : 1mm
-parallel to path of
- placement of restoration
-
-stop short of margin 

17. -. Con.. proximal grooves :
-it can be U shape ( most used )
V shape ( lest retentive and more conservative )
box shape (more retentive and lest conservative )
- Proximal flare 

18. ADVANTAGES OF PROXIMAL GROOVES : -
 1. to improve retention
 2.distinct resistance to lingual displacement
 3. reinforce the margin of restoration at this
area
 4. act as guide during placement

19. 4- OCCLUSAL OFFSET :
1mm .wide groove made on the lingual incline
of the buccal cusp . inverted V shape lie at
uniform distance from occlusal finish line
- improve the strength of the casting
- reinforce the margin of restoration at this area
(Ingraham R University of Southern California School of Dentistry,
(
1969

20. 5- BUCCAL AND OCCLUSAL BEVEL MARGINS :
-
- 45 degree bevel
-
( for structural durability )

21. - KEEP METAL DISPLAY TO MINIMUM

22. (1-2)- MANDIBULAR MOLAR 34 CROWN
• The principles used in a premolar
preparation also apply for a maxillary molar
except:
1- no occlusal offset
2 - shoulder on buccal why ??
-Additional retention is required because of the shorter
crown length of mandibular teeth
- the buccal aspect of the madibular teeth includes the
functional cusp

23. ( functional cusp )
Max . post Position of the finising line
on facial surface
( terminat near the bucco-occlusal line
angle)
Mand.post  Position of the
finising line
1mm gingival to the lower
occlusal contact with upper teeth
( because the buccal cusps in
lower are the functional cusps )

24. 3- proximal grooves extended more buccaly
(because no need for esthetic )
4 - beveled from mesial to distal

25. (1-3) – REVERSE 3/4 CROWN
Buccal surface is included in
the preparation instead of the
lingual surface.
Indications :
1- Mandibular molars with
damaged buccal surface and
intact lingual surface
2-Mandibular molars with sever
lingual inclinations to be used
as bridge retainers

26. (1-4)- 78 CROWN
Three quarter crown with extension on buccal surface from
distal side ( mesiobuccal cusp is not veneerd )
- Have better retention and resistance than three quarter
crown
Shillingburg 3ed pg 160
Indications: (generally used in maxillary 1st molars with :
- Intact mesiobuccal cusp
- When there is extensive distal caries or previous
restoration

27. (1-5 ) -PROXIMAL HALF CROWN
A three quarter crown with the distal
surface rather than the buccal has been
left intact
Contraindications:
- Caries on the distal surface
- Patient with bad oral hygiene

28. Indications: ( single restoration or as retainer
on)
- Upper molars where it is difficulte to gait
access to the distal surfaces
- Lower mesially tilted molars
- (Shillingburg HT Jr. Bridge retainers for tilted abutments. N M Dent J
1972)

29. - (2) ANTERIOR PARTIAL VENEER CROWN :
- pinledge preparation
(2-1)- maxillary canine 34 crown
(2-2)- maxillary central incisor
pinledge

30. PINLEDGE PREPARATION
Pinledge retainer(2):
pinledge (1998): a partial-coverage crown or retainer
that
incorporates pins that insert into corresponding
pinholes prepared in the tooth
Ref .( The glossary of prosthodontics, ninth adition ) pg 69

31. Indications
1-undamaged anterior teeth
in dentitions with little or no caries.
2-if esthetic appearance is highly important
3-splinting of anterior teeth
bridge retainer(8) (9)
Alteration of lingual contour of maxillary teeth
Protection of incisal edge of anterior teeth in case of attrition
Contraindications:
1-Young patients with large pulp
2-poor oral hygiene ,multiple caries
3-non vital teeth
4- thin tooth ( narrow labiolingual diamention)

32. Advantages :
conservative
minimum gingival involvement
adequate retention
accessibility for finishing and hygiene
disadvantages:
less retention than complete coverage
technically demanding
not useble on nonvital teeth

33. (2-1)- MAXILLARY CANINE 34 CROWN
1-placment of guiding groove on the lingual
surface
Use : round ended diamond
Depth :1mm


34. 2- lingual surface reduction
Clearance is verified before reduction of the
other half.
Use : football-shaped diamond
Depth :1mm

35. incisal bevel. No significant change has
occurred in the incisocervical height.
Use : round ended diamond
Depth : 0.7 mm

36. 4-Axial reduction ( lingual chamfer margin)
Use : teperd tungsten carbide fissre bur

37. 5-retention forms
Proximal grooves and lingual pinhole
Use : Fine –grit tapered diamonds or tungsten
carbide bur
5-retention forms
Proximal grooves and lingual pinhole
Use : Fine –grit tapered diamonds or tungsten carbide bur

38. THE PINHOLE IS PREPARED
STAGES:
1- A small horizontal ledge
Use : large, tapered or cylindrical tungsten
carbide bur
2- a slight dimple is created (Indentations)
Use : small round bur at the intended pinhole
location;

39. 3- preparation pilot hole
Use : small-diameter twist drill* (it must be parallel to
the precise path of placement of the restoration)
4- the preparation is completed with a tapered tungsten
carbide bur to a pinhole depth of approximately 2
mm;

40. 4-Indentations:
. left and right sides of the incisal ledge and center in
the
cervical ledge
use : small, round bur

41. (2-2)- MAXILLARY CENTRAL INCISOR PINLEDGE:
1-Guiding grooves on lingual
surface
Use : round ended diamond
Depth :1mm
2-lingual reduction ,
placement of incisal bevel
Use : football-shaped diamond
Depth :1mm

42. 3-Incisal and cervical ledges
Prepare two ledges
use : a cylindrical tungsten carbide bur.
Recommended minimum ledge width is 0.7
mm

43. 5-preparation of Pinholes
depth of 2 mm ( pinholes will be in sound
dentin )
Use ; tapered tungsten carbide bur

44. INLAYS AND ONLAYS
Materials :
Cast metals
high gold alloys
low gold alloys
palladium silver alloys
base metal alloys
Tooth colored
1-Porcelain
2-composite

45. Indications:
onlay
inlay
1- carious teeth with
intact buccal and
lingual cusps
2- Need to replace
MOD
amalgam
3- Low caries rate
4- Patient’s request for
gold instead of
amalgam
1-Small carious lesion
2- remaining dentin
Adequate for support
3- Low caries rate
4- Patient’s request for
gold instead of
amalgam or composite
resin

46. CONTRAINDICATIONS:
onlay
inlay
1- Extensive caries
2- Poor plaque control
3- Short clinical crown
or
extruded teeth
4-Lesions extending
beyond transitional line
angles
1- Extensive caries
2- Poor oral hygiene
3- Small teeth
4- young patient
5- Poor dentinal
support

47. ADVANTAGES :
onlay
inlay
1- Support of
cusps
2-High strength
+
Same advantages
of inlay
1- Superior material
properties
2- Longevity
3-No discoloration
from
corrosion
4- Least complex
cast restoration

48. DISADVANTAGES :
onlay
inlay
1- Lacks retention
+
Same disadvantages
of inlay
1- Less conservation
of tooth
structure than
amalgam
2- May display metal
3- Gingival extension
beyond ideal

49. PREPARATION :
:
a-Mesio-occlusal or Distal-occlusal Inlay
Preparation
b-Mesio-occlusal–distal Onlay Preparation

50. A-MESIO-OCCLUSAL OR DISTAL-OCCLUSAL INLAY
PREPARATION
Outline Form :
Occlusal preparation
- Penetrate the central groove in 3 points just
depth of the dentin : (typically about 1.8 mm)
use : tapered tungsten carbide bur
- connect between points
- use : tapered tungsten carbide bur
- extend the outline proximally ,then layer of enamel
should remain between the side of the bur and the

51. -box preparation
width of the gingival floor : (1 mm
mesiodistally)
Use : tapered tungsten carbide bur

52. -caries excavation :
Use : excavator , round bur in the low speed
-axiogingival groove and bevel placement
- groove at junction of axial and gingival walls
 enhance resistance form , and prevent distortion of the
wax pattern during manipulation
Use : GMT

53. -bevels:
 provide strength and durability
place 45 degree gingival margin bevel , 0.8 mm
wide
proximal bevels on buccal and lingual walls
occlusal bevel

Use : tapered tungsten carbide bur or fine-grit
diamond

54. B-MESIO-OCCLUSAL–DISTAL ONLAY
PREPARATION (MOD) :
similar to The occlusal outline and proximal
boxes of an inlay ,The additional steps :
1- occlusal reduction and a
2-functional (centric) cusp ledge:

55. outline form
prepare the occlusal outline ( 1.8 mm deep)
use : tapered tungsten carbide bur
- prepare the boxes:
- extend the outline both mesially and
distally
-caries excavation :
Use : excavator , round bur in the low speed

56. -occlusal reduction
-place grooves on the functional cusps
(1.3 mm deep , allowing 0.2 smoothing )
-place grooves on the nonfunctional
cusps
( 0.8 mm)
use : tapered tungsten carbide bur

57. -connect the grooves
Use : tapered tungsten carbide
bur
- prepare (1.mm functional cusp ledge):
provides the restoration bulk in this
high stress area
( structural durability )
1 mm apical to the opposing centric
contacts , it extend to the proximal
boxes
Use : cylindrical tungsten carbide
bur

58. margin placement :( bevels)
 continues bevel on all margins
 gingival bevel (45-degree)
 bevels on functional(1.5mm) and nonfunctional
cusps(1mm) ( for additional bulk at margins )
Use : tapered tungsten carbide bur or fine-grit
diamond

59. Thank you