This document discusses all ceramic crown preparation. It defines all ceramic crowns as non-metallic full coverage restorations used to restore teeth functionally and esthetically. Advantages include superior esthetics, excellent translucency, and good tissue response, while disadvantages include reduced strength without a metal substructure and difficulty obtaining well-fitting margins. Indications for all ceramic crowns include discolored teeth, teeth with enamel defects, and excessive attrition. Contraindications include posterior teeth and teeth under heavy biting forces. The document outlines the facial, incisal, lingual, and proximal tooth reduction techniques needed to properly prepare teeth for all ceramic crowns.

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