Restoring the endodontically treated tooth

By Dr.Swathi Pai on Tuesday, January 13, 2009 with 0 comments

The primary purpose of a post is to retain a core. Posts do not reinforce teeth.

Threaded posts induce the most stress and cemented posts induce the least.

2 advantages of custom tapered cast post and cores:

  1. high strength with a better fit

  2. conserves more radicular tooth structure

3 disadvantages of custom tapered cast post and cores:

  1. not as retentive

  2. greater chance of splitting the tooth (wedge)

  3. multiple visits required

2 indications for custom tapered cast post and cores:

  1. non-circular canals in x-section

  2. canals with extreme tapering and flaring

3 advantages of pre-fabricated, parallel sided, dowel with core:

  1. high strength

  2. good retention

  3. reduced stresses

2 disadvantages of pre-fabricated, parallel sided, dowel with core:

  1. loss of tooth structure (makes tooth fit the post)

  2. possible corrosion with stainless steel posts

2 indications for pre-fabricated, parallel sided, dowel with core:

  1. straight canals

  2. circular canals in x-section

the length of a custom cast post and core should be at least as long as the clinical crown.

Ferrule design: 1mm of coronal tooth structure occlusal to finish line—increases fracture resistance.

4-5mm of gutta percha should remain.

3 months is the maximum amount of time for a temporary restoration to remain on an endodontically treated tooth. After 3 months, re-treatment should be performed.

Length of post: -optimal = 2/3 to ¾ the root length

-minimal = the length of the clinical crown.

-or length of root contained in remaining bone

Width of post: -depends on root width and morphology

Should not be greater than 1/3 of the root diameter and should be as

parallel as possible.

Post should be surrounded by 1mm of sound dentin

1-2mm of cervical tooth structure should remain or extend finish line cervically to recapture tooth structure.

Need post and core if significant tooth structure has been lost and if the tooth will serve as an FPD or RPD abutment.

Treatment considerations for anterior teeth:

  1. conservative access, intact incisal edge, and marginal ridges with minimal

restorations: acid etched resin composite.

  1. conservative access, intact incisal edge, large mesial and distal restorations that communicate with the access opening, and minimal class V restoration or ½ the tooth structure missing: cast metal post and core with crown.

Treatment considerations for premolars:

  1. conservative access on lower first premolar: amalgam or resin composite to plug access opening.

  2. all other premolars: cuspal coverage amalgam core and crown if sufficient retention of the core can be obtained. If chamber is insufficient, or tooth will serve as an abutment, then a custom cast post core and crown is needed.

Treatment consideration for molars:

  1. conservative access opening with conservative mesial and distal restorations: amalgam chamber retained cuspal coverage.

  2. if access opening involves greater then 1/3 of the occlusal table from mesial to

  3. distal, or if cusps are involved: chamber retained amalgam core and crown.

  4. extensive loss of coronal tooth structure, chamber unable to accommodate an amalgam core (less than 4mm of chamber height): cast post and core.

Core materials: amalgam, resin composite, glass ionomer, or cast metal

When removing gutta percha you can use warm pluggers if immediate removal occurs after completion of NSRCT. Use rotary instruments or warm pluggers if delayed removal occurs.

Category: Prosthodontics Notes



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