post and core

Post and core

some studies have indicatedthat minimally damaged endodontically treated teeth

without posts are more resistant to fracture than teethrestored with posts and cores

DefinitionDowel

•a post, usually made of metal that is fitted

•into a prepared root canal of a tooth that has

•had endodontic therapy

Core

the coronal aspect of the post foundation

Choice of Restorative Technique for the Endodontically Treated tooth

•1-Type of Tooth ( Anterior V.S. Posterior 2-amount of remaining coronal tooth structure

Case evaluation

•Endodontic Considerations

•Periodontal Considerations

•Prosthetic Considerations

Endodontic Considerations

•1 .Good apical seal•2 .No sensitivity to pressure

•3 .No exudate•4 .No fistula

•5 .No apical sensitivity•6 .No active inflammation

•7 .Retreatment should occur if there are signs•or symptoms indicating failure

Periodontal Considerations

•1 .Extensive coronal destruction may require Crown Lengthening:

•a.to Re-establish biologic width

•b .to Provide coronal tooth structure to

•incorporate ferrule into cast restoration

Ferrule effect 1.5-2mm of coronal tooth structure to achieve

resistance form

Prosthetic Considerations

•1 .Extent of coronal destruction

2 .Other factors to evaluatea. Tooth type (anterior vs. posterior)b. Position in archd. Occlusal and prosthetic forces applied toTooth

Factors affecting the retentionof prefabricated post restorations .

•POST LENGTH

•POST DIAMETER

•POST DESIGN

•LUTING AGENTS

POST LENGTH

•1 .The post should be longer than the crown.

•2 .The post should end halfway between the crestal

•bone and the root apex.

•3 .The post should be as long as possible without

•disturbing the apical seal

Optimal conservative postplacement, with appropriate

length, width and fit, for amaxillary canine that

required a crown due to theamount of lost tooth

structure

POST DIAMETER

•Increasing the diameter of the post does

•not provide a significant increase in the retention of the post ; however, it can increase the stiffness of the

•post at the expense of the remaining dentin and the

•fracture resistance of the root.

;

Therefore post diameter must be controlled to preserveradicular dentin, reduce the potential for perforations,

and permit the tooth to resist fracture

.

Overly wide post and resultant root fracture.

POST DESIGN

•smooth

•Serrated

•threaded

POST DESIGN

•Prefabricated•Custom made

POST DESIGN

•Tapered

• .Parallel-sided

LUTING AGENTS

•Luting agents, including zinc phosphate, polycarboxylate,

•glass ionomer

PREPARATION OF THE CANAL SPACE

AND TOOTH

•1 -gutta percha should be

•removed with an endodontic heat carrier until the

•desired length is reached. A minimum of 4 to 5 mm of

•gutta percha must remain to preserve the apical seal

2-root canal reamers can beused to widen the canal space by a reaming action to

ensure a relatively round preparation

3-twist drills arethen used to shape the canal

Methods of placement of custom made posts

•Direct method

•Indirect method

Custom Made Post: Direct Technique

Custom Made Posts: Indirect

Core material

•Amalgam

•Composite

•Glass ionomer