1. OBJECTIVES OF RESTORATION ENDODONTICALLY TREATED TOOTH
dr shabeel pn

2. Stated as ‘3R’s
Reinforcement
Replacement
Retention

3. Reinforcement A - Dowel
Reinforcement of the remaining tooth structure is achieved with dowel and coping
DOWEL – post extending approximately 2/3rd the length of the root canal
A - Dowel

4. COPING –is a band of metal approximately 1-2mm in width surrounding the coronal portion of the dowel to obtain a ‘ferrule’ effect & protect the tooth from fracture
Coping

5. REPLACEMENT
Replacement of missing tooth structure is achieved with the core
CORE – is the coronal
extension of the dowel
that provide optimal
retention for final
Restoration.
B - CORE

6. RETENTION
Is supplied by
Dowel for core
Core for final restoration

7. Retention of a dowel (post) is affected by the
Preparation geometry
The post length
Diameter
Surface texture
Luting agent.

8. Preparation geometry
parallel-sided posts are more retentive than tapered posts
threaded posts are the most retentive of all, because retention is proportional to the total surface area.

9. Post length post length increases retention increases
A post that is too short will fail, whereas if the post is too long may damage the seal of the root canal filling and there is risk of root perforation if the apical third is curved or tapered.

10. Post diameter
Increasing the post diameter in an attempt to increase retention
but is not recommended because it may unnecessarily weaken the remaining root

11. Post surface texture
A serrated or roughened post is more retentive than a smooth one, and controlled grooving of the post and root canal considerably increases the retention of a tapered post.

12. Luting agent.
The choice of luting agent seems to have little effect on post retention
Zinc phosphate and glass ionomer have similar retentive properties, polycarboxylate and composite resin slightly less.

13. REQUIREMENT OF CORE & DOWEL

14. Length of the post should be equal or longer than the estimated clinical crown
The post must have an occlusal stop to prevent displacement apically
They should be resistance to rotational force
Post Should be of sufficient thickness resist displacement and assist restoration & stabilization
A minimum of 4 mm root canal filling should be there to provide adequate seal

15. Features Of Successful Design

16. THANK YOU