Implant Margins

JohnWilson

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To mask poor workmanship ? Not in my book...



The cement its still the weakest link, no matter how much better it became... I'd still plan for the worst and hope for the best...

Both of you missed my sarcastic point, and unless you are routinely taking a PA of your restorations before they leave the lab ZERO I will promise you some of your units will show this from time to time. I pretty sure Ken did not try and play catch up with a bad milling.

How big of a gap do you think that is? This is 100% "clinically acceptable", can it be improved yeah of course,

Anytime I see this on the mesial like others have stated its a contact issue. If you routinely cement free end singles one at a time on the model if the contact is ever so heavy this can happen. If you have a perfect keyway like the Variobases have cement off the model and adjust your contacts after cementation.
 
Ken Knapp

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Both of you missed my sarcastic point, and unless you are routinely taking a PA of your restorations before they leave the lab ZERO I will promise you some of your units will show this from time to time. I pretty sure Ken did not try and play catch up with a bad milling.

How big of a gap do you think that is? This is 100% "clinically acceptable", can it be improved yeah of course,

Anytime I see this on the mesial like others have stated its a contact issue. If you routinely cement free end singles one at a time on the model if the contact is ever so heavy this can happen. If you have a perfect keyway like the Variobases have cement off the model and adjust your contacts after cementation.
John,

Thank you for the clarification.

This same dentist now wants new standard crown (non implant) remade for lite contact instead of adding a little glaze to the old crown, since glaze isn't zirconia.

Ken
 
JohnWilson

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Now thats just getting silly for a contact. If you are adding glass to a marginal ridge to close a contact then I see their point, adding glaze/frit to solve a light contacts thats totally fine.

Good luck with this client I hope she is worth the frustrations.
 
CatamountRob

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John,

Thank you for the clarification.

This same dentist now wants new standard crown (non implant) remade for lite contact instead of adding a little glaze to the old crown, since glaze isn't zirconia.

Ken
That's just ridiculous.
 
zero_zero

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Both of you missed my sarcastic point, and unless you are routinely taking a PA of your restorations before they leave the lab ZERO I will promise you some of your units will show this from time to time.

I'm pretty sure it does when I'm not around Banghead...got a very strict QC in place, higher than average internal remakes too...
 
doug

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Just curious, why send you an Xray of this when it would be easily seen by just holding it in your hand with no loupes? Was someone trying to make a point? Good points, John. What I meant by does the doctor know the standard is that he should be the person who has the ultimate responsibility and had better know what is acceptable, not what he thinks is.
 
CatamountRob

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Just curious, why send you an Xray of this when it would be easily seen by just holding it in your hand with no loupes? Was someone trying to make a point? Good points, John. What I meant by does the doctor know the standard is that he should be the person who has the ultimate responsibility and had better know what is acceptable, not what he thinks is.
Doug, I could be mistaken, and I didn't initially get this either, but I think it was only visible in the X-Ray because the cement wasn't radiopaque. It was cemented at the lab and thus it wasn't visible in hand, with or without loupes.
 
Gru

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Got an account who wants all his posterior FCZ's polished all around, no glaze whatsoever...doesn't mind me charging extra for the added labor...Dontknow

Probably read or was told that glaze will chip off eventually and cause excessive wear. A lot of work, but if you can charge extra for it, congrats!
 
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Standards, objective standards..Every dentist has a different preference. Some want the emergence profile as you noted but most want the crown adapted to the tissue for a natural tooth emergence from the tissue. My largest implant dentist, who does his implants likes the crowns adapted to the tissue.

My understanding is that there isn't clinical results supporting your argument.
I agree each Dr. has a specific tissue emergence profile. The problem I see with your restoration is that you have a problem with the way the restoration will merge with the implant. Any gross overhangs and open areas in the immediate vicinity of the mating surface of the implant will be detrimental to the long term bone health around the threads of the implant. Here is an Emax hybrid abutment that I finished yesterday. My flash is on loan to another laboratory technician so I couldn't quit get a clear picture of the interface, but you can see the smooth transition lines from the Ti abutment to the emax material with a small cement line. I will redo this abutment for the over spray of the aluminum oxide on the ti abutment but the form is what I am pointing out. Even on stock abutments that have prepped margins my standard is a smooth transition between the two. As for objective standards, your client is the arbiter of these standards. If they demand a 20 microns then that is the standard. If that is beyond what you are willing to do, then you need to move on from that Dr. I have established my standards of acceptability and that is what I use as my objective standards, but this is what I am willing to achieve. If I get a new client that demands more, then I have to examine my process and see if that is acceptable for me to achieve. If not they go elsewhere.
 

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ztech

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Got an account who wants all his posterior FCZ's polished all around, no glaze whatsoever...doesn't mind me charging extra for the added labor...Dontknow
I also hand polish my zirconia but only on the occlusal. The non-occluding surfaces are smoothed and glazed.
 
prestige.dental

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If I see a X-ray on the delivery like this, I will say it looks pretty good.

This could be a concern if it was a natural tooth.

She is probably new to implant dentistry.
 
Tom Moore

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If the margin standard is 25 microns from the lab then the biggest bugs in your mouth at about 3 microns can link up 8 wide and walk under that margin if it is not sealed with cement.

Nothing is going under this implant margin because there is nothing for the little nastys to eat between the ti and cement so they can't excrete the corrosives that make the mess with crowns on natural teeth.


All margins are open before the cement flows, its a matter of how far.


Can the newer cements and a flame diamond make it smooth and closed. Hell to the yes.
 
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sonlab

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Dentist returned two screw retained implant crowns for margins based on X-ray.

Crown on left for zirconia overhang on margin, on left. Crown on right for open margin, on right.

To me they seem acceptable.

What is the objective standard for crown/implant margins?

Thoughts?

Ken
Both open margin on mesial and overhang on distal is over 75 microns. My guestimate is closer to 400- 500 microns or .4 to.5 mm. The Cement gap on the distal of #29 and of mesial of #30 is closer to 75 microns. A 75 micron opening on xray is a bit larger than the tip of an endo file that is size .06 .

A 400 micron opening is a tip of a Size 40 endo file which looks about right from the xray- you might want to consider doing it over.
 
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sonlab

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sample2.JPG sample3.JPG sample1.JPG The discrepancy on Sample3 on the distal between Ti base and implant crown of #30 is about 100 micron and on the mesial less than 60 micron.
Sample1 and Sample2 less than 60 microns
 
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Mr Wilson has a whole new look...
 
dmonwaxa

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All that FCZ money, and don't wanna buy a razor. ;):D
 

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