13. Restoration of the Endodontically Treated Tooth Flashcards
Introduction
• Special techniques needed to restore an endodontically treated tooth
• Usually considerable amount of tooth structure has been lost
– Due to:
• ____
• Endodontic treatment
• Previous ____
caries
restorations
Introduction
• Factors influencing technique choice
– Type of tooth
• ____, canine,
premolar, molar
– Amount of remaining ____ tooth structure
• Most important indicator in determining prognosis
incisor
coronal
Treatment Planning • Before being restored, endodontically treated tooth must be evaluated for: – Good \_\_\_\_ seal – No sensitivity to pressure – No \_\_\_\_ – No fistula – No apical \_\_\_\_ – No active inflammation
apical
exudate
sensitivity
Treatment Planning
Inadequate endodontically filled teeth should be re- treated before fixed prosthodontic treatment is begun
If doubt remains, the tooth should be observed for several ____
until definitive evidence of success or failure
months
Treatment Planning
• Microleakage studies show significant increase in microleakage at ____ months
– if endodontically treated tooth is left exposed to oral environment for 3 months or longer, recommend ____
3
endodontic retreatment
Treatment Planning
Must account for the ____ of the remaining tooth structure, weighed carefully against the ____ to which the restored tooth will be subjected.
Most of the failures are influenced by ____. As loading increases, failure rates ____.
strength
load
load
increase
Treatment Planning
• Cast post and core
• Prefabricated post and core
If sufficient tooth structure is present to support and retain a core build up, no ____ is necessary
post
Treatment Planning
• Cast post and core
– One-piece foundation restoration for an ____ treated tooth comprising a post within the root canal and a core replacing missing coronal structure to form the tooth preparation
– Two step technique
• post and crown ____ fabricated at same visit
Post and coronal portion prepared intraorally
One piece post and crown ____
Post is fabricated in the laboratory
Post and core is cemented
Crown is fabricated
endodontically
NOT
unacceptable
Treatment Planning
• ____
– A rod fitted into the prepared root canal of a natural tooth
– Provides ____ for the core
• ____
– Replaces any lost coronal tooth structure, allowing optimal tooth preparation geometry to be achieved
Post (dowel)
retention
core
Treatment Planning • Prefabricated post – Different materials for post – \_\_\_\_ – Fiber composite – \_\_\_\_ – Glass fiber --- ceramic and glass fiber for \_\_\_\_
– Different core materials » Composite \_\_\_\_ » Amalgam » \_\_\_\_ ionomer – Two step procedure
metal ceramic esthetics resin glass
Treatment Planning
Main Clinic
• Composite Resin Build Up Materials – Fluorocore (Dentsply)
• ____-releasing dual cure composite core build up material
– Clearfil DC Core (Kuraray)
• ____-cure, radiopaque, ____ component core build up material
fluoride
dual
two
Treatment Planning • Prefabricated metal post – made of different metals • \_\_\_\_ • Ni-Cr • \_\_\_\_ • Au-Pt • \_\_\_\_ • Stainless \_\_\_\_ wire – have high \_\_\_\_ and are very rigid – Main clinic: • \_\_\_\_ (Coltene) • Integrapost (Premier)
pt-au-pd co-cr ti steel modulus of elasticity parapost
Treatment Planning
• Fiber composite posts – Increase in \_\_\_\_ – Bundles of stretched aligned \_\_\_\_ embedded in resin matrix – Less stiffness and strength than \_\_\_\_ – Shorter \_\_\_\_ than metal posts – More easily \_\_\_\_ • If endo retreatment needed – Main clinic: • \_\_\_\_ fibre post 3D (3M) • Fluoropost system (Caulk,Dentsply)
popularity glass carbon fibers ceramic and metal longevity retrievable rely-x
Treatment Planning • Esthetic posts: – \_\_\_\_ posts (high strength ceramic) • Very strong and rigid – \_\_\_\_ composite – Woven \_\_\_\_ (polyethylene) posts • \_\_\_\_ and more flexible than ceramic – CAD/CAM • Impression scanned and digitized. Then \_\_\_\_ milled
zirconia ceramic fiber weaker zirconia
Treatment Planning
Literature Review
• Primary function of post is to provide ____ for the core
– Lovdahl and Nichols (JPD 38:507,1977)
• The strength of an endodontically treated tooth is directly related to the bulk of the remaining ____
– Hock (1976, masters thesis)
• No significant increase in resistance to ____ with the use of a post
retention
dentin
fracture
Post placement DOES NOT ____ teeth.
Studies have shown it provides no significant ____
strengthen
reinforcement
Disadvantages of Cemented Post
• Additional ____ procedure to place
• Removal of additional ____ structure to
accommodate post
• Difficult to ____ if failure
– ex. Inadequate core retention
• Complicates or prevents future ____ re-treatment
Only place post if need to retain ____
operative tooth remove endodontic core
Considerations for Anterior Teeth
• Endodontically treated anterior teeth do NOT always need full ____
– Depends on amount of remaining tooth structure
• Post is only recommended for teeth requiring ____
• If tooth discoloration, but tooth is intact, recommend attempt ____, first and direct ____
coverage
full coverage
bleaching
restoration
Considerations for Anterior Teeth
• When loss ofcoronal tooth structure is ____ or tooth will be ____ or ____ abutment, ____ mandatory
– Retention and support of core derived from within canal due to limited coronal ____
extensive
FDP
RPD
full crown
Considerations for Anterior Teeth
Endodontic access and small proximal lesions
Restore with ____ resin restorations
Endodontic access and large proximal lesions
____restoration needed to restore
composite
full coverage
Considerations for Posterior Teeth
• Subject to greater loading than anterior teeth
• Morphologic characteristics – Cusps can be ____ apart
– more susceptible to fracture
• Endodontically treated posterior teeth should receive ____ coverage to prevent fracture
– Gives best protection against fracture
wedged
cuspal
Considerations for Posterior Teeth
Minimal tooth destruction. No facial or lingual damage
>
Possible ____ with cuspal coverage or ____ coverage
Moderate to severe damage
>
____ build up or ____-core and crown for premolars/molars
Total coronal destruction
>
____-core and
crown, possible crown ____ for premolars/molars
onlay
full
core
dowel
dowel
lengthening
(1)Conservation of Tooth Structure (a)Preparation of Canal
Six Features of a Successful Preparation
Positive ____ stop (to minimize wedging)
Adequate apical ____
Adequate post ____
Minimum canal ____ (no undercuts)
Vertical wall to prevent ____ (similar to box)
Extension of definitive restoration onto ____ tooth structure
horizontal seal length enlargement rotation sound
(1)Conservation of Tooth Structure
(a)Preparation of the Canal
• Remove only minimal tooth structure from canal
• Excessive enlargement can perforate or ____ the root
– May ____ during post cementation or function
• Thickness of remaining ____ is prime variable in fracture resistance of root
• Photoelastic stress analysis has shown internal stresses reduced with ____ posts
weaken
split
dentin
thinner
(1)Conservation of Tooth Structure (a)Preparation of the Canal
• Root canal should be enlarged only enough to enable post to fit accurately and passively
– Enlargement generally accomplished ____ file sizes beyond largest file size
one or two
(1)Conservation of Tooth Structure (b)Preparation of Coronal Tissue
• Endodontically treated teeth often have a substantial amount of missing tooth structure
– ____, existing restorations, endo access
• Cast post and core requires substantial reduction which results in minimal coronal ____
– Need to remove undercuts for preparation
• Save as much ____ tooth structure as possible
The amount of remaining ____ is the most important predictor of clinical success
caries
dentin
coronal
tooth structure
(1) Conservation of Tooth Structure
(b) Preparation of Coronal Tissue
• Tooth preparation and loss of internal tooth structure for endodontic treatment results in ____, fragile tooth structure
– Often need to reduce this in ____
thin
height
(1)Conservation of Tooth Structure (b)Preparation of Coronal Tissue
Need to maintain as much coronal tooth structure as possible
Extensive coronal tooth structure lost. More forces are transmitted to ____
root
(1)Conservation of Tooth Structure (b)Preparation of Coronal Tissue
• Extension of axial wall of crown apical to
missing tooth structure provides ____
– ____ used to fit the root or crown of tooth instead of completely ____ core material
– Thought to help bind remaining tooth structure together
– Helps prevent ____ of an endodontically treated tooth
ferrule
metal band
encircling
fracture
(1)Conservation of Tooth Structure (b)Preparation of Coronal Tissue
• If unable to achieve ferrule effect or if less
than 2mm coronal tooth structure remains circumferentially, ____, ____, or combination is indicated.
crown lengthening
orthodontic extrusion
(1)Conservation of Tooth Structure (b)Preparation of Coronal Tissue
• Crown lengthening – A surgical procedure
to increase extent of ____ tooth structure for restorative or esthetic purposes by apically positioning the ____, removing supporting ____ or bot
supragingival
gingival margin
bone
(1)Conservation of Tooth Structure
(b)Preparation of Coronal Tissue
• Orthodontic
extrusion
– Movement of tooth beyond the natural ____ that may be accompanied by a similar movement of their ____
occlusal plane
supporting tissues
2)Retention Form
(a)Anterior Teeth
• Post retention affected by
– (A)Preparation ____ – (B)Post ____
– (C)Post ____
– (D)Post ____
– (E)____ agent
Simultaneous dislodgement of crown with post and core results from inadequate \_\_\_\_ form.
geometry length diameter surface texture luting retention
(2)Retention Form
(A)Preparation Geometry
• Different canals have different canal configurations
• Ideal post has ____ walls (minimal taper)
– Canals with CIRCULAR cross section
• Can accommodate ____ sided post
– Canals with ELLIPTICAL cross section
• Need some ____ to ensure retention and eliminate undercuts
• For parallel post, need to considerably enlarge canal which would ____ tooth
parallel
parallel
taper
weaken
(2)Retention Form (A)Preparation Geometry
• Post retention increases as vertical wall taper is ____
• Use of a parallel sided post in tapered canal requires considerable ____ of post space
reduced
enlargement
(2)Retention Form
(B)Post Length
• Post should be as long as possible without jeopardizing apical seal
– Ideal to maintain ____mm apical seal
– If post is ____ than coronal height of clinical crown, unfavorable due to possible root fracture
5
shorter
