RESTORATIVE CONSIDERATIONS FOR ENDODONTICALLY TREATED TEETH.

www.endodonticpractice.co.nz

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

www.endodonticpractice.co.nz

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

www.endodonticpractice.co.nz

Pathway to success

• Rubber dam isolation

www.endodonticpractice.co.nz

• Adequate Access

Pathway to success

Pathway to success• Locate all the canals

MB 2 is Not a Myth!!

www.endodonticpractice.co.nz

• 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

www.endodonticpractice.co.nz