Endo teeth Flashcards
The teeth become _____ and ____ susceptible to decay, fracture, and
breakdown.
softer; more
T/F: Once pulp has been removed, and nerve sensation stopped, the tooth loses its
ability to monitor changes in proprioception. Meaning you can bite harder
on these teeth before you feel pain or discomfort.
True
The tooth now is less strong and both of the above criteria result in a higher
likelihood of _______
FRACTURE
____ fracture
Fracture in enamel only (crack line) or fracture in
enamel and dentin
The fracture line does not extend apical to the
cemento-enamel junction
There is no associated periodontal probing defect
The pulp may be vital requiring only a crown
If pulp has irreversible pulpitis or necrosis, root
canal treatment is indicated before the crown is
placed
Favorable
____ fracture
Fracture in enamel and dentin
The fracture line may extend apical to the
cemento-enamel junction but there is no
associated periodontal probing defect
There is an osseous lesion of endodontic
origin
Questionable
\_\_\_\_ fracture Fracture line extends apical to the cementoenamel junction extending onto the root with an associated probing defect
Unfavorable
________ tooth fractures occur because:
- Greater occlusal forces
- Divided occlusal surface (Cusps and Fossa)
- Fillings weaken tooth ability to hold together
Posterior
Crowns did NOT significantly improve the
success rates of endodontically treated
______teeth when ample tooth
structure remains.
ANTERIOR
Crowns significantly improved
success rates of endodontically
treated _______ teeth
POSTERIOR
Crowns are only indicated on RCT Treated ______ teeth when:
-They are structurally weakened by large or multiple restorations
-They need substantial changes in form or color that cannot be achieved
by more conservative means
ANTERIOR
Need at least __mm for a ferrule.
2 mm
If sufficient natural tooth structure remains, a _______ will
fill the RCT access and chamber to restore the lost tooth
structure.
Build up/Core
_______ has been as used a core material for a long time
but not as much now.
-Disadvantage – not retentive, does not bond, more tooth
reduction needed
-Advantage – strength
Amalgam
_______ are used much more now for core build up
-Disavantage – not as strong
-Advantage – usability, bonding, more conservative tooth
reduction
Composite resins
If tooth structure is missing, and restorability is
compromised but not condemned, a ___ can
be used to add strength to the core build up as
you restore the lost tooth structure.
post
Why do we use a ____?
-RCT teeth with inadequate tooth structure to retain a core
-Teeth that have lost more than 50% of coronal tooth structure
-Single rooted teeth since the anatomy of the pulp chamber
does not offer mechanical retention.
-Teeth with significant response to lateral forces of occlusion.
post
Teeth that have lost more than __% of coronal tooth structure need a post
50%
In these situations, post or no post?
-Preparation of a post space adds risk to the restorative
prognosis
-Higher likelihood of fracture or perforation
The needs for a post vary between anterior and posterior.
No post
Post or no post? Anterior Teeth – Patient presents with an intact anterior moderate sized lingual RCT access with a resin composite restoration in the access If tooth has darkened: -Internal bleaching -Possible veneer or composite
No opst
In access hole, place bleaching material and seal the access with a temporary fill. May need to be repeated several times. Can last for a reasonable amount of time and may need to be touched up in the future.
Internal bleaching
When more than \_\_\_% of coronal tooth structure has been lost - A post and core will be necessary for retention of a crown. The post and core is meant to resist lateral forces which would cause the crown to dislodge.
50%
A _____ is the vertical axial wall that encircles the
tooth which a crown will use to resist fracture
ferrule
Minimum ferrule =___mm beyond the core
2mm
T/F: Without the proper ferrule, root fracture is much more l
ikely on anterior teeth due to high lateral forces in
mastication.
True
When remaining tooth structure has large
access and a shorter clinical crown,
generally a post is or is not necessary?
No necessary
If extensive coronal destruction exists, and a post is necessary to retain the core:
Use the _____ and _______ root and canal
longest and straightest
Which canal should be used for a post in max molars?
Palatal
Which canal should be used for a post in mand molars?
Distal root
_____ tooth –
Significant variation in root length, curvature, bifurcation, and width.
Use a post only in roots that have ample bulk and a straight root anatomy.
Use a post on a premolar if:
Substantial tooth structure is missing (eg –post is placed in canal to replace lost cusp).
If the tooth is under substantial occlusal forces.
If the height of the tooth in MI is tall
Remember – a
2mm ferrule is
minimally required
Premolar tooth
Which tooth is the exception to the premolar tooth assumption that would contraindicate a post?
Patient habits and conditions need to be
assessed to ensure occlusal forces are not
heavy or lateral.
It may be possible to avoid both a crown and
post on this tooth after RCT with a
conservative access fill.
1st mand pm
____ teeth often only need a build up and then secondary retentive features such as grooves, boxes,
pins, bonding, or utilizing the access hole.
Molars teeth
_____: ability of the post to resist vertical dislodging forces
Post length and taper
Active or Passive design
Cement used
Retention
\_\_\_\_\_\_" ability of the post and core to withstand lateral or rotational forces Amount of remaining tooth structure Post length and rigidity Anti-rotation features Presence of a Ferrule
Resistance:
__-__ the length of the root is ideal
Minimum length at least that of the clinical crown
½ to 2/3
__-__mm of Gutta Percha left at apex to keep the seal of the
Gutta Percha
4-5 mm
A post too ____ allows the forces to act with greater
stress leading to a higher incidence of root fracture.
short
A post that does not leave __-__mm at the
apical for the RCT seal will compromise
the tooth:
The post often is too big at the apex and can
cause root fracture.
The apical seal is compromised and
therefore, recurrent infection can occur.
4-5 mm
As a general rule, molar post
spaces greater than __ mm apical to
canal orifice increases the potential
for root perforation.
7 mm
Post preparation diameter should not exceed
___ of the root at the CEJ
1/3
Leave at least __ mm of sound dentin at mid-root
1 mm
Ideal diameter of post should only be ___-__mm depending on the particulars of the
tooth
- 6mm –
1. 2mm
A ______ instrument melts the GP and then a warmed
plugger compacts the GP vertically.
heated
Canal is instrumented with _____ or ______
rotary instrument.
-Pink GP should be visualized being removed during
the entire use of these instruments.
-This should be done SLOWLY
-Don’t cut on end
Gates Glidden or Peazo Reamer
__-__ posts engage the surrounding root material
usually via threads or a serrated edge.
Active posts
______ posts fit into the canal without engaging
the surrounding root material.
Passive posts
______ posts are the most retentive
-Create higher stress on the root and
therefore have a higher incidence of
root fracture
Threaded Parallel
_____ are close behind in
retentiveness.
-High stress at apex and therefore higher
incidence of root fracture
Serrated Parallel
______ Posts are least retentive
-Less incidence of root fracture due to
least amount of stress on root
-Can be adequate.
Tapered Passive
______ Post – Custom Post
-Resin pattern sent to lab to be cast in metal
alloy
Custom Passive
_______ Posts – Cemented in root with
core build up of composite or amalgam
Pre-Fabricated
\_\_\_\_\_\_\_ Post Advantages: Anti-Rotational properties Core is part of post Can be preservative of tooth structure as the post fits the space Disadvantages: Multiple appointments needed Tapered design is not as retentive Dark un-esthetic core Higher incidence of root fracture as post is harder material than root and if occlusion is off, post will not break, root will
Custom Cast
\_\_\_\_\_\_\_ Post Advantages: Increased retention within root Ease of placement More versatile to a wider range of tooth root shapes Post will often break before root will Disadvantages: Post space needs to be slightly larger than cast Core retention to post can be a problem Possible rotation Metal posts still have un-esthetic color
Pre-Fabricated
_____ posts have difficulties
at times with narrowing of tooth root and can
lead to root tip fracture.
Parallel
A \_\_\_\_\_\_ tooth with a canal shape that is ovoid presents a dilemma. A pre-fab post is not stable on its own as the canal shape allows the post to rock back and forth so: -A cast post can be made -A Pre-Fab post can used and cemented -A Two Pre-Fab post technique can be used to stabilize the Pre-Fab Post
PM tooth
_______ Technique
One major post goes to length and height for Core build
up, but canal orifice allows post to wobble.
A minor (smaller) post can be placed into the canal as far
down as it can go to stabilize the major post.
This reduces the stress on the major post which would have
been supported only by cement.
Then the two posts are cemented in the canal together
and core build up placed.
Primarily for Anterior and select premolars.
Two Post
______ Technique
A red Duralay resin impression is made of the post space.
Tooth is temporized while Duralay is sent to the lab.
Post is tried in and cemented.
Cast post is used as build up as well.
Cast Post
The post should extend to ______ so that
the build up has the full support of the post.
the height of your build up
Challenging occlusion? Little occlusal room? Significant vertical overlap? Bruxer/Grinder? If so, a \_\_\_\_ post is the first choice as it will not break or separate. The risk is root fracture however if the forces on the tooth are still too strong.
Cast post
\_\_\_\_\_\_\_ Posts: -Main advantage is better esthetics -Modulus of Elasticity is similar to dentin -Must use Resin cement (self-adhesive) -Less Root fractures than metal posts Post will usually break before post does -Failures typically occur in teeth with little coronal tooth structure.
Fiber reinforced
What types of cements are good to use in post situations?
Dual or self cure resin cements
