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Root canal specialist recommended onlays - will I be pushed into crowns - and have I left it too late for restoration?



Aug 15, 2021
I had four root canals done 2.5 years ago.

Three of them had associated large abscesses that were wicked away up into the sinus cavity that were only discovered on the CT scan. I only found out I had the infections in the first place by self-requesting a panoramic x-ray - they had been there for years.
Because of this, it was thought I should wait a while for the abscesses to heal before getting restoration. I got another CT scan a year later and 2 of the 3 were healing well, the other one with the longest infection was slower but still healing and looking encouraging.

The teeth themselves and the gums around them all look healthy, and the teeth are firmly rooted in.

Anyway - I delayed some more and now it is 2.5 years since I got the root canals.
My dentist has retired and I have to see a new one.
I have a letter from my root canal specialist (he did the root canals, not my dentist) saying I need onlays put on 2 of the teeth, and the other 2 teeth do not need restoration.

UR6 - I have a missing tooth underneath (massive gap so no bite at all from the tooth above) so no restoration
UR5 - no restoration needed
LR7 - onlay
UL7 - onlay

I really don't want crowns if onlays will work, as I've had trouble in the past with getting my bite right. I don't have any crowns or onlays currently on any teeth.

I'm nervous about seeing someone new, and I'm worried he will say I need to get crowns on all 4 teeth.

Is it likely the new dentist will want to do crowns instead of onlays?

And have I left it too long after getting the root canals to get the onlays done?

Thank you very much.
Hi Annie,
No, you have not left it too late to get the onlays done.
As to whether the new dentist would prefer to place crowns rather than onlays? Well, that may well depend on what seems to work best in his hands. Whilst an onlay preserves more tooth structure than a crown, for it to be more successful long term , it needs the dentist to be very skilled with the preparation and bonding. I would say that crowns are a bit less technique sensitive. So I would rather have a crown if my dentist felt they worked best in his hands.
Hope this helps

Thank you drhirst, that is really helpful and reassuring.
The other thing I have been concerned about is - do onlays and crowns often cause bite problems, and/or feel weird or alien in the mouth?
And can bacteria get into the space where it is bonded to the tooth if it loosens with age, and end up causing decay under the crown/onlay? It seems such a pity to grind into a healthy-looking tooth (though without pulp) for the onlays/crowns.
I'm a bit apprehensive as finally my mouth is finally feeling comfortable, and I don't want mess that up by getting onlays/crowns which cause ongoing bite problems or infections. Though I do know that getting the recommended onlays/crowns are important on root canalled teeth to lessen the chance of future breakage.
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Hi @Annie364,
Everything you wrote about crowns and onlays is true. All dentistry will eventually fail, often by the mechanisms you described. The question is will it outlast you!!!. On balance, a root filled molar will almost certainly last longer with a crown or onlay as it seals the tooth better and is more likely to prevent it breaking.

Thanks ever so much Lincoln, that is very helpful.
So do you find in your experience that even onlays will often cause bite problems for people?
And do you find that people often find that onlays feel weird in the mouth?
I'm hoping that maybe an onlay will be better than a crown in this way.
In my experience a well made onlay or crown will not cause any bite problems and do not feel weird at all in the vast majority of cases.