Restoring Teeth Prior to Root Canal Treatment

Restoring Teeth Prior to Root Canal Treatment
Before commencing endodontic treatment, teeth should be made caries free and well restored. The restoration must withstand access cavity preparation and still remain joined and sealed to the tooth. This will prevent contamination of the canal with infected (carious) dentine
prevent saliva contamination of the canal due to leaky restoration
facilitate placement of rubber dam and clamps
prevent bits of dressing / filling / tooth dropping into the canal during endodontic treatment
help prevent fracture of the tooth/dressing in between visits

Restoration of a dressed tooth
You may need to treat a tooth which has had the pulp removed, and is currently dressed. You must restore the tooth before continuing RCT., but you are worried about accidentally filling the pulp chamber with restorative material.
Place C/W in the chamber to cover the orifices.
Fill the chamber with kalzinol, allow to set.
Restore the tooth.
Re-prepare the access cavity through your restoration until you reach the Kalzinol.
Break up and wash out the Kalzinol with an ultrasonic (or air) scaler
Remove the cotton wool
You can also use a large Gutta Percha Cone (size 60 + ) to act as a guide to the canal entrance. Place the cone into the orifice, and pack cotton wool and dressing around it.

Restoration of a tooth with a buccal cavity: Keeping the canal patent.
Sometimes, a pulpal exposure results from a buccal (or L,M,D) cavity. If you restore the cavity conventionally, you may block the canal.
Prepare an occlusal access cavity. Clean the pulp chamber.
Place a (parapost) smooth plastic post through the accesss cavity as far as the canal opening. You may need to trim the tip of the post to fit. The post should be lightly smeared with vaseline to aid removal. (You can also use a large Gutta Percha Cone instead of a Parapost.)
You will be able to see the side of the post through the buccal cavity.
Restore the buccal cavity.
Remove the post. You now have access to the canal.
You may need to refine the access cavity to remove any excess restorative.

What to restore with?

Amalgam
No early seal -
Copalite varnish needed (or panavia).
Not adhesive - may fall out during access cavity preparation
Easily identified
May affect EAL readings (care needed)
Composite
Complicated bonding system needed
Multi-layer light-curing needed
Hard to identify
Resin-modified Glass Ionomer
Excellent easy bond to tooth
Can be applied in bulk (if self-curing)
Hard to identify
Kalzinol
Will not withstand dam clamps
Will break up during endodontic treatment and fall into canal
May not last between visits
Not adhesive
Easy to identify
Copper Ring (last resort...)
When no walls are present, a copper ring can hold a filling in place during endo.
You must ask: if you need a copper ring now, what are the chances of properly restoring the tooth after endo is completed?