r estorative considerations for endodontically treated teeth. ada meeting 19 july 2011
TRANSCRIPT
RESTORATIVE CONSIDERATIONS FOR ENDODONTICALLY TREATED TEETH.
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ADA Meeting 19 July 2011
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 PlanCoronal 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 toothThey 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
• Prefabricated • Long• Thick• Serrated• Parrallel• Rigid• Cement
Clinical Guidelines
What core material do you use?
Final Restoration/Core
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Direct restoration
• Amalgam
Advantages
- Proven track record- Quick and easy to place- Relatively Inexpensive- Good coronal seal
Disadvantages
- Mercury- Colour- Does not bond to teeth- Require retentive features
• Composite
Advantages
- Matches tooth colour- Less toxic- Minimal preparation- Bonds to teeth
Disadvantages
- Technique sensitive- Coronal leakage
Direct restoration
• Glass Ionomer
Advantages
- Matches tooth colour- Less toxic- Minimal preparation- Moisture tolerant- Releases flouride
Disadvantages
- Technique sensitive- Weak
Direct restoration
• Indirect CAD/CAM – CD4, Cerec
Advantages
- Matches tooth colour- Less toxic- Quick turn-around- Bonds to teeth
Disadvantages
- Technique sensitive- Brittle - Cost - set up
- patients
In-direct restoration
• Indirect lab based – Gold, PFM, PJC, Zirconia
Advantages
- Matches tooth colour- Less toxic- Good seal- Restores tooth resistance
Disadvantages
- Time consuming- Brittle – (Porcelain)- Cost - Delayed
In-direct restoration
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 FerruleWhen 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 is NO more important than the root filling itself.
The Coronal Seal
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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• Adequate Access
Pathway to success
Pathway to success• Locate all the canals
MB 2 is Not a Myth!!
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• Thorough chemo-mechanical preparation
Pathway to success
• Well constructed provisional restoration
Pathway to success
• Unidentified Iatrogenic damage
Pathway to success
Perforationwww.endodonticpractice.co.nz
• Produce an acceptable root filling and construct a good coronal seal
Pathway to success
Outcomes
• Favourable - Healing- Pre-operative PA area 73%-97%- More than 2 roots 84%- No pre-operative PA area 88%-97%- Single rooted teeth 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
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