RESTORATIVE CONSIDERATIONS FOR
ENDODONTICALLY TREATED TEETH.
ADA Meeting
19 July 2011
www.endodonticpractice.co.nz
Endodontics
• The branch of dentistry that deals with
maintaining healthy dental pulp in a state
of health and the treatment of diseased
dental pulp to promote healing and
restoring the health of the tooth and the
surrounding peri-radicular tissues to
maintain the function and aesthetics of
the teeth.
The Consultation
- History
- Exam
- Diagnosis
- Treatment plan
- Treatment
- Recall
The Plan
Coronal Restoration
- Remaining tooth structure
- Periodontium
- Strategic importance
- Occlusion
- Material(s)
- Additional Retention
- Nayyar technique
- Posts?
- PINS
Root Canal Treatment
- Non-surgical
- Surgical
Do we need posts?
Posts
Posts DO NOT strengthen root filled tooth
They retain the core
NO POST is the best option
However……….
Posts
• Type - Prefabricated not cast post
Posts
• Shape – Parallel sided not tapered
Posts
• Length – Long not short
The Crowbar Effect
Posts
• Diameter – Debatable α material
Posts
• Material – Rigid and not flexible
Gold, fibre such as carbon, glass, or even zirconia, or stainless steel, or
titanium
Posts
• Design – Serrated (not smooth or screw type)
Serrated
Smooth
Screw
Posts
• Cement – Type and amount
Whatever type of cement that is used for the
post it t must fit loosely in the canal. If you are
a getting a tug back with your post, you have a
problem.
Case
Clinical Guidelines
•
•
•
•
•
•
•
Prefabricated
Long
Thick
Serrated
Parrallel
Rigid
Cement
What core material do you use?
Final Restoration/Core
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Direct restoration
• Amalgam
Advantages
Disadvantages
- Proven track record
- Quick and easy to place
- Relatively Inexpensive
- Good coronal seal
- Mercury
- Colour
- Does not bond to teeth
- Require retentive features
Direct restoration
• Composite
Advantages
Disadvantages
- Matches tooth colour
- Less toxic
- Minimal preparation
- Bonds to teeth
- Technique sensitive
- Coronal leakage
Direct restoration
• Glass Ionomer
Advantages
- Matches tooth colour
- Less toxic
- Minimal preparation
- Moisture tolerant
- Releases flouride
Disadvantages
- Technique sensitive
- Weak
In-direct restoration
• Indirect CAD/CAM – CD4, Cerec
Advantages
Disadvantages
- Matches tooth colour
- Less toxic
- Quick turn-around
- Bonds to teeth
- Technique sensitive
- Brittle
- Cost
- set up
- patients
In-direct restoration
• Indirect lab based – Gold, PFM, PJC, Zirconia
Advantages
Disadvantages
- Matches tooth colour
- Less toxic
- Good seal
- Restores tooth resistance
- Time consuming
- Brittle – (Porcelain)
- Cost
- Delayed
Clinical Guidelines
• A virgin tooth is prestressed where the cusps are in constant
tension pushing towards each other to allow for the flexing
occlusal forces.
• Occlusal filling – 20 %. I will happily replace this with
amalgam or composite.
• MO or DO – 40 % I would restore them with amalgam or
composite. However as soon as you roughly lose just over
2/3(M-D) x 1/3 (B-L) of the tooth I would seriously consider
cusp capping with amalgam or composite
• MOD – 60 % At this stage, I will do a full coverage
restoration with amalgam or composite
• If a cusp is missing then the ability to withstand fracture
reduces even further.
• When restoring a tooth, one must look at the remaning
tooth structure and then decide what filling they will do. This
is the primary determining factor.
• The aim of the game to restore the tooth to as close to its
original state.
Do all root filled teeth require crowns?
The routine use of posts and cores in anterior teeth is not
required unless there is gross loss of coronal tooth structure. In
fact there is lesser leakage with a bonded composite that a post
core and crown. If you are going to make a veneer, you are
better off making a crown. Generally too much tooth structure
is lost to make a nice veneer so crown the tooth especially if it
is heavily filled
Root canal treated posterior teeth, usually needs a crown when
they are cusp capped. As a general rule, It can increase the
chances of success by 6-11 fold.
In any case the core material that is used does not matter if
there is sufficient tooth structure to provide a ferrule effect.
The Ferrule
When using a core build up in either anterior or posterior
teeth, ideally there must be at least 2 mm of sound tooth
structure above the free gingival margin for the placement of
a crown. This is the ferrule. This increases the resistance of
teeth to fracture and also allows for the margins from getting
plaque accumulation and subsequent secondary decay. 1mm
ferrule double the resistance to fracture. Uneven ferrule is
better than no Ferrule. So don’t pick up that bur and trim the
last remaining millimetre of supra-gingival tooth just so that
your cast post is easier to fit.
Crown Lengthening Surgery
•
•
•
•
1.0 mm cemetal-fibrous interface,
1.0 mm epithelial attachment,
1.0 mm sulcus
1.0 mm finishing margin
= 4.0 mm above crestal bone
Orthodontic extrusion is better than CLS
How long before a crown
• Review in 6 months to check for healing. If no
change. Review in another six months.
• Crown when healing visible at the recall.
• If crowning will reduce the chances of leakage
such post core crown for anteriors. Crown
immediately after RCT.
Is coronal seal more important?
The Coronal Seal
The coronal seal is NO more important than the
root filling itself.
Adequate
root filling
Coronal
seal
Clinical Guidelines
• Timing of final restoration
• Tooth fracture prior to final restoration;
• Inadequate final restoration
– lacks ideal marginal integrity
– forces of occlusal function
– deterioration
• Recurrent decay
How do we improve our success rate?
Pathway to success
Sensibility test
Pathway to success
• Correct diagnosis
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Pathway to success
• Rubber dam isolation
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Pathway to success
• Adequate Access
Pathway to success
• Locate all the canals
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MB 2 is Not
a Myth!!
Pathway to success
• Thorough chemo-mechanical preparation
Pathway to success
• Well constructed provisional restoration
Pathway to success
• Unidentified Iatrogenic damage
Perforation
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Pathway to success
• Produce an acceptable root filling and
construct a good coronal seal
Outcomes
• Favourable - Healing
- Pre-operative PA area
- More than 2 roots
- No pre-operative PA area
- Single rooted teeth
73%-97%
84%
88%-97%
93%
• Overall
- Healing
41% - 86%
Conclusion
•
•
•
•
Each case must be treated on its own merit
There is no “recipe” to ensure success
Ensure correct informed consent
Refer if unsure
“Do or do not... there is no try.” – Yoda
www.endodonticpractice.co.nz