After a root canal treatment the pain is gone and the tooth feels normal again, so it is fair to ask why we then recommend a crown. The short answer: the root canal deals with the infection, and the crown protects what is left of the tooth.
A treated tooth is a weaker tooth
By the time a tooth needs a root canal, it has usually lost a lot of its structure to decay, an old large filling or a crack. The treatment itself then needs an opening through the top of the tooth to reach the canals. What remains is often a shell of walls around a filling.
Back teeth take most of the force when you chew. A thin wall under that force can split, sometimes down into the root. A crack like that often cannot be repaired, and the tooth that the root canal saved has to come out.
What a crown does
A crown covers the whole tooth above the gum, like a helmet. Biting forces press on the crown and spread evenly, instead of wedging the walls of the tooth apart. It also seals the top of the tooth so bacteria cannot leak back into the cleaned canals.
How soon should it go on?
Soon. The temporary filling placed after a root canal is not designed to last, and it can wear or leak within weeks. Until the crown is fitted:
- chew on the other side where you can;
- avoid hard food on that tooth: nuts, ice, hard sweets, bones;
- come back if the temporary filling feels rough, high or loose.
Many teeth that crack after a root canal crack in the gap between the treatment and the crown.
When a crown may not be needed
Front teeth carry much lighter forces. If a front tooth still has most of its structure after the root canal, a well-bonded filling may be enough. We look at each tooth and tell you which it needs, and why.
Which crown?
Metal-ceramic crowns are strong and have been used for decades. All-ceramic and zirconia crowns look more natural and suit teeth that show when you smile. We go through the options and their costs at your visit. See crowns and bridges for more, or read about root canal treatment.