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One-sided crown lengthening & lopsided crown?

My tooth #3 is badly decayed on the mesial side.  It will likely need RCT and a crown (it currently has a temp. filling).  Most of the tooth mesial of the pulp chamber is gone, and the decay goes down to the gum (there's maybe 1-1.5 mm of tooth left to the bone).  The distal side also has some decay but not anywhere near as much and there is plenty of tooth above the gum on that side.

I've been told I need 2-3 mm crown lengthening surgery both to ensure there is enough space from the crown margin to the bone and to ensure there is enough solid tooth beneath the core buildup to have a good ferrule effect.  My dentist says it should be possible to do the crown lengthening only on the mesial side (ie b/w #3 and #4), and then put on a crown with a margin that goes lower on the mesial than on the distal.

Does doing crown lengthening only on one side of a tooth often cause a 'reverse architecture' problem?  Would a lopsided crown like that, with the ferrule that is on solid tooth structure somewhat diagonal, be very weak?
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540545 tn?1377622918
MEDICAL PROFESSIONAL
Great!  I'm glad you did your homework.  So I did a little bit of my own homework and tried to find some information for you in regards to the three side vs four side predictament.  

I couldn't find too much.  It seems that that accept standard is indeed to have four sides as it the most desirable and provides the most tooth structure support to prevent a fracture.  It seems to vaguely state that the lack of a ferrule effect increases the risk of fracture but doesn't specifically say how much is lacking and how much increased risk.  I can imagine it would be rather difficult to say specifically how much as each person's mouth and tooth are very individualized.

I would say that a three sided ferrule has a fair to good prognosis excluding any other findings with your teeth.  

As for the crack, its hard to say how and where it would crack.  Cracks depend on the biting forces in your mouth as well as what you may happen to be chewing at the time.  

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Avatar universal
Thank you for the information.

I have a follow-up question.  I've now consulted with several different dentists, and not all think CL is necessary; the difference of opinion is based on whether to get a proper ferrule you need tooth structure on all four sides.  There is healthy tissue above the bone for the margin all around, so biologic width is not an issue; the problem is that on the mesial side of any core buildup, there would be virtually no dentin left if I don't get CL.  Does a tooth with a 3-4 mm dentin ferrule on the other three sides of the core buildup and no dentin on the mesial face a very poor prognosis?  If it were to crack due to insufficient ferrule, is the crack likely to be one that would make restoration impossible and/or complicate an extraction and replacement with an implant?
Helpful - 0
540545 tn?1377622918
MEDICAL PROFESSIONAL
I don't personally do crown lengthening so I can't really answer your questions for you.  You should probably consult with a periodontist if you have any concerns.  You may also want to post this question in the oral surgery expert forum to see if he may know.

Have you discuss with your doctor other types of crown lengthening?  If you're concerned about a defect on the mesial side, you can also orthodontically lengthening the tooth by pulling it out of its socket and then removing the excess bone.  Also, with that extensive a treatment, sometimes you can also consider extraction and placement of a dental implant instead.  Especially if the prognosis is questionable to fair.

I personally am in favor of maintaining as much bone as possible in the patient's mouth.  I would tend not to do any crown lengthening and favor placement of a dental implant instead.  But that's my own personal opinion.  I don't have your radiographs or performed an exam in your mouth but I wanted to let you know of some other options.  

Sorry I can't be of more help.


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