All ceramic crown preparation seminar

all ceramic crown prepartion
esthetic crown
fixed prosthodontics

2. Today:
we will talk about all ceramic crown preparation.

3. DefinitionDefinition
•Non metallic full coverage ceramic
restoration . Restoring the prepared
ant. Teeth functionally & esthetically

4. •Advantages
Superior esthetic

5. Excellent translucency
Good tissue response
Conservative reduction of facial
surface
Appearance of restoration influenced
by color of luting agent

6. DisadvantagesDisadvantages
Absence of metal substructure
Reduced strength of the restoration
Significant tooth reduction is necessary
on proximal & lingual surface
Difficulty in obtaining well fitting margin

7. * Not effective as retainer for fixed
prosthesis
* Wear observed on functional surface
of natural tooth
* Wear may occur on functional
surfaces of natural teeth that oppose
porcelain restoration
•

8.  IndicationsIndications
in ant. Teethin ant. Teeth
* * Discolored tooth Discolored tooth
* * Tooth with enamel defectsTooth with enamel defects
* * Fracture teeth Fracture teeth
** Bilateral proximal decay with incisal Bilateral proximal decay with incisal
angle involved (class 4 ).angle involved (class 4 ).

** Unilateral proximal decay Unilateral proximal decay


9. •* * Excessive attrition tooth Excessive attrition tooth
* * at rampant caries at rampant caries
* * malformed and rotated teethmalformed and rotated teeth
*functions:*functions:
**All ceramic is used as foundation All ceramic is used as foundation
restorationrestoration
* * for endodontically treated teeth to for endodontically treated teeth to
overcome esthetic problem associated overcome esthetic problem associated
with metal post and core systemwith metal post and core system

10. •Contraindication Contraindication
* * With posterior teeth With posterior teeth
* * young patients young patients → large pulp,high epithelium → large pulp,high epithelium
attachment attachment
* * Deep or heavy bites Deep or heavy bites
Bad habits ( ex. nail biting )Bad habits ( ex. nail biting )
* * If occlusal load is unfavorableIf occlusal load is unfavorable
* * At long span bridge At long span bridge
* * when other more conservative rest. is when other more conservative rest. is
indicated indicated

12. PrecautionsPrecautions
• Over tapered prepared cingulum
→ ↓ Resistance & Retention
→ exert wedge like force thus ↑
stress causing fracture
•Horizontal surface at the junction of
prepared fossa & lingual wall should be
preserved → reduce stresses

13. •Lingual ridge of canine not completely
reduced → ↑ rotational resistance

14. Facial reductionFacial reduction
Placing depth orientation groove
Depth of grooves should be 0.8 mm
as at finishing become 1 mm
Reduce the areas between grooves
Two planes in preparation to provide
adequate esthetics without affecting pulp
. 1
st
plane is on incisal two third
. 2
nd
plane is on one-third

15. * facial reduction should extend around the
facial-proximal line angles & fade out on the
lingual aspect of the proximal surface
* end of flat end diamond forms shoulder
finishline

16. Incisal reduction Incisal reduction
•reduction 1.5 : 2 mm clearance to provide
esthetic & adequate strength restoration
•45 degrees towards lingual surface
• 3 depth grooves approximately 1.3 mm to
allow additional loss during finishing
• tooth structure between the grooves should
be reduced
•Incisal reduction should be perpendicular to
the plane of incisal half of labial reduction

18. Lingual reductionLingual reduction
Cingulum reduction is done by Football Cingulum reduction is done by Football
shaped diamond shaped diamond
 care should be taken to prevent over at care should be taken to prevent over at
the junction between cingulum & lingual the junction between cingulum & lingual
walwal
l l
A short lingual wall reduces the retention A short lingual wall reduces the retention
of the restoration of the restoration

20. Proximal reduction Proximal reduction
* The shoulder should be at least 1.0 mm
wide
* care should be taken to avoid undercuts at
the junction of axial walls & the shoulder
finish line

21. Finishing the preparation Finishing the preparation
* * All axial surfaces should be smoothed using All axial surfaces should be smoothed using
finishing stones & bursfinishing stones & burs
* * Roundation of any remaining sharp line Roundation of any remaining sharp line
angles to avoid porcelain fractureangles to avoid porcelain fracture

* * Uniform width of shoulder finish line Uniform width of shoulder finish line
(approximately 1mm ) to resist forces directed (approximately 1mm ) to resist forces directed
from the incisal from the incisal

22. prepared by : prepared by :
Moataz Abodief Moataz Abodief
Mostafa El-Sadic Mostafa El-Sadic
Nour Mohammed Nour Mohammed
Waleed MohammedWaleed Mohammed
Dentistry College ; Assiut UniversityDentistry College ; Assiut University
thanksthanks