Most back teeth need a crown after a root canal, and many front teeth do not. A molar or premolar takes heavy chewing force and is usually crowned to prevent cracks. A front tooth with a small opening and strong walls can often be sealed with a filling instead.
Which tooth was treated and how much of it is left decide the answer. How long you wait matters too.
Why a Tooth Needs Protection After a Root Canal
During root canal treatment, the dentist makes an opening through the top of the tooth, removes the pulp and seals the canals. The infection is dealt with, but the tooth is left with less of its own structure. Most teeth that need a root canal have also lost structure to deep decay, a crack or a large old filling before treatment begins.
A crown covers the whole tooth above the gumline and holds what remains together when you bite. It also seals the top of the tooth, which helps keep bacteria from leaking back into the cleaned canals.
Back Teeth vs Front Teeth
Molars and premolars do the grinding. Their cusps get pushed apart every time you chew, and a hollowed-out back tooth with only a filling is more likely to split. That is why a crown is the usual recommendation for back teeth after a root canal.
Front teeth mostly bite and tear, with less force. If the access opening is small and the walls of the tooth are intact, a tooth-colored filling is often enough. A front tooth may still need a crown when:
- A large part of it was already lost to decay or a fracture
- It already had big fillings on several sides
- It has darkened and other ways of improving the color are not suitable
- You grind or clench your teeth heavily
Some back teeth fall in between. When the outer walls are thick and strong, an onlay, which covers the chewing cusps without wrapping the whole tooth, can be an option. Your dentist decides this after looking at the tooth and the X-ray, so ask which choice fits yours and why.
How Soon Should You Get the Crown?
Sooner is better. Your dentist will tell you when the tooth is ready for its crown after the root canal.
The timing has been studied. A 2016 study in the Journal of Endodontics followed back teeth treated at a university endodontic clinic for up to eight years. Teeth that received their crown more than four months after the root canal were about three times as likely to be extracted as teeth crowned within four months.
That study looked at one clinic and found an association, so it cannot predict what will happen to any one tooth. It does point the same way as everyday experience: the longer a treated back tooth goes without its crown, the more chances it has to crack or leak.
What Can Happen If You Wait
After the root canal, the opening is usually closed with a temporary or interim filling. A temporary filling is not designed to last, and two problems can develop under it.
The first is leakage. Saliva and bacteria can seep past a worn temporary filling into the canals, and a tooth that gets reinfected may need the root canal redone.
The second is a fracture. A crack that stays above the gumline can often be repaired with a crown. A crack that runs below the gumline or down the root often means the tooth cannot be saved. Replacing a lost tooth with an implant generally costs more than crowning the tooth would have, and it takes several months.
Until the crown is placed, chew on the other side, avoid hard and sticky foods on that tooth, and keep brushing and flossing it. Call your dentist if the temporary filling feels rough, loose or comes out.
What Getting the Crown Involves
The tooth is numbed, although a tooth with a completed root canal has no live nerve inside, so most of the sensation is in the gum around it. The dentist may first rebuild the inside of the tooth with a filling material called a build-up. When very little tooth is left above the gumline, a small post may be placed in one of the treated canals to help anchor the build-up. The tooth is then shaped and the crown is fitted to it.
A traditional crown takes two visits: an impression and a temporary crown at the first, then the permanent crown a couple of weeks later once a dental lab has made it.
The same-day option
Redondo Beach Dental Group makes crowns in the office with CEREC. A same-day crown is scanned, designed, milled from a ceramic block and bonded in one appointment, with no temporary crown and no second visit. That removes the gap in which a temporary can leak or the tooth can crack. Not every tooth is a good fit, and some cases still do better with a lab-made crown, so ask whether yours qualifies and whether the crown can be done at the same visit as the root canal or at a follow-up.
A same-day crown at Redondo Beach Dental Group typically costs $1,200 to $2,000 per tooth before insurance. The total depends on the tooth, the material and whether a build-up or post is needed first. Dental plans usually treat a crown as a major restorative procedure, subject to your deductible and annual maximum, so ask how your plan applies before treatment.
Frequently Asked Questions
Is it worth getting a crown after a root canal?
A crown after a root canal is usually worth it for a back tooth, because a treated molar or premolar left with only a filling is more likely to crack. For a front tooth with most of its structure intact, a filling is often enough, and your dentist can tell you which applies.
Can I wait 3 months to get a crown after a root canal?
One 2016 study compared back teeth crowned within four months of a root canal with teeth crowned later, and the later group was lost more often. A temporary filling can also wear and leak, and the tooth can crack in the meantime, so ask your dentist whether your tooth can safely wait.
How long does a crown after a root canal take?
A crown after a root canal takes either two visits or one. A lab-made crown needs a preparation visit and a fitting visit about two weeks apart. A same-day CEREC crown is designed, milled and placed in a single appointment.
Why didn’t my dentist give me a crown after a root canal?
A dentist may skip the crown after a root canal when the treated tooth is a front tooth with a small opening and strong walls, which can often be restored with a filling. If you had a back tooth treated and were not offered a crown or onlay, it is reasonable to ask why.
Does it hurt to get a crown after a root canal?
Getting a crown after a root canal is usually comfortable, because the tooth no longer has a live nerve and the gum around it is numbed. The gum can be a little sore for a day or two afterward.
Will a tooth rot under a crown?
A tooth can decay under a crown, even after a root canal. The crown cannot decay, but the natural tooth at the edge where the crown meets it can. Brushing, flossing around the crown and regular checkups help catch it early.
Have a Temporary Filling and Not Sure What Comes Next?
Ask us whether your tooth needs a crown or an onlay, and whether it is a candidate for a same-day crown. Call Redondo Beach Dental Group at (310) 542-6988 or request an appointment online.