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 toothDiscolored tooth
** Tooth with enamel defectsTooth with enamel defects
** Fracture teethFracture teeth
** Bilateral proximal decay with incisalBilateral proximal decay with incisal
angle involved (class 4 ).angle involved (class 4 ).
** Unilateral proximal decayUnilateral proximal decay

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

10. •ContraindicationContraindication
** With posterior teethWith posterior teeth
** young patientsyoung patients → large pulp,high epithelium→ large pulp,high epithelium
attachmentattachment
** Deep or heavy bitesDeep 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 bridgeAt long span bridge
** when other more conservative rest. iswhen other more conservative rest. is
indicatedindicated

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
. 1st
plane is on incisal two third
. 2nd
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 reductionIncisal 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 FootballCingulum reduction is done by Football
shaped diamondshaped diamond
 care should be taken to prevent over atcare should be taken to prevent over at
the junction between cingulum & lingualthe junction between cingulum & lingual
walwal
ll
A short lingual wall reduces the retentionA short lingual wall reduces the retention
of the restorationof the restoration

20. Proximal reductionProximal 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 preparationFinishing the preparation
** All axial surfaces should be smoothed usingAll axial surfaces should be smoothed using
finishing stones & bursfinishing stones & burs
** Roundation of any remaining sharp lineRoundation of any remaining sharp line
angles to avoid porcelain fractureangles to avoid porcelain fracture
** Uniform width of shoulder finish lineUniform width of shoulder finish line
(approximately 1mm ) to resist forces directed(approximately 1mm ) to resist forces directed
from the incisalfrom the incisal

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