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
11.
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
17.
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
19.
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
