prosthetic dentistry II

1. The university of georgia
Posterior Partial Veneer Crown Preparations
Atheer Ahmed Abed 1330129
Prosthetic Dentistry II

2. DEFINITION
 A restoration that restores all but one coronal surface
of a tooth, usually not covering the facial surface.
A partial veneer crown is a restoration covering two or
more surfaces of a tooth

3. TYPES OF PARTIAL COVERAGE
CROWNS
 1)Three-quarter crown
2)Modified three-quarter crown
3)Seven-eighth crowns
4)proximal half crowns

4. INDICATIONS FOR PARTIAL
VENEER CROWNS
 Partial veneer crowns are a conservative measure and
are preferable to the complete veneer restoration.
Intact or minimally restored teeth.
Teeth with crown length that is average or that exceeds
the average.
 Teeth with normal anatomic crown form, i.e., without
excessive cervical constriction.

5. CONTRAINDICATIONS FOR
PARTIAL VENEER CROWNS
 High caries rate.
Teeth with extensive restoration
Deep cervical lesion
difficult to establish finish line , if area is sensitive
complete coverage crown is indicated
Teeth with short clinical crown –
difficult to achieve resistance and retention form.
Thin teeth – preparation of retention grooves is difficult.
Poor alignment of teeth in the dental

6. ADVANTAGES OF PARTIAL
VENEER CROWNS
 Partial veneer crowns have several advantages over
complete crowns:
The tooth reduction is conservative.
The esthetics surpass the complete veneer cast crown.
Margin accessibility for finishing and cleaning is improved.
 Complete seating of the casting is more easily verified.
Complete seating of the casting during cementation is
enhanced by diminished hydraulic pressure.
Electric pulp testing can be conveniently accomplished on
the intact enamel surface

7. DISADVANTAGES OF PARTIAL
VENEER CROWNS
 The partial veneer crown is not as retentive as a
complete veneer crown.
Skillful preparation is critical to avoid metal display.
The partial veneer crown preparation is limited to fairly
intact teeth with normally shaped crown and an average
length clinical crowns

8. Fundamental Principles of
Design
 1) To impart strength to the remaining portion of the
tooth crown.
2) To provide maximum resistance and retention form to
the finished restoration.
3) To preserve esthetics by conservation of tooth
structure, thus limiting the display of gold on buccal
and labial surfaces

9. ROTARY INSTRUMENTS USED
FOR TOOTH PREPARATIONS
 Round end tapered diamond,
Torpedo diamond,
Short needle,
Long needle,
Flame diamond,
Small wheel diamond,
Tapered fissure burs
End cutting bur

10. Steps for preparation of
partial veneer crowns
Outline Form
Lingual reduction
Incisal reduction
Lingual axial reduction
Proximal axial reduction
Proximal box or groove placement
Occlusal or incisal offset placement
Facial bevel
Finishing the preparation.

12. Maxillary posterior three
quarter crowns
Occlusal reduction
1) round-end tapered diamond is used
2) Depth orientation grooves are made on the triangular
ridges and the developmental grooves 1.0mm on the
non functional and 1.5mm on the functional cusp

13.  3)At the occluso-facial line angle groove is made only
0.5mm deep to minimize the display of metal.
4)Tooth structure from between the grooves is removed
according to cuspal contours

14. Functional Cusp Bevel
 Should be parallel to the inward facing inclines of the
cusps of the opposing tooth, at depth of 1.5mm creating
45˚ angle with the axial wall

15. Lingual Axial Reduction
 Torpedo diamond creating a definite chamfer all over.
Over inclination of the lingual wall frequently occurs.
Check at all times for over inclination.

16. Proximal Reduction
 Initially thin needle diamond is used in sawing motion to
just break the contact with the adjacent tooth Once
contact is broken, torpedo diamond is used to create a
definite chamfer finish line and complete the axial and
proximal reduction

17. Axial Finishing

18. Proximal Groove

19. Facial bevel

20. Completed three quarter crown

21. Referance
 www.google.com
www.indiandentalacademy.com

23. Any question
Thank you