What would cause this?

[rkm rdt]

Here are the pics of a case delivered recently.
Anterior veneers from lateral to lateral.Emax veneered.
The interproximal prepping was minimal but I was able to achieve a path of insertion for each veneer.

Dr. called to say the veneers did not seat and were 1mm short on the margins although there was lingual seating..
Therefore the dr retook impression #2 . The veneers did not seat on the new dies .
Notice the length of the preps on model #1 compared to#2.

What would cause this? How did the 1st impression distort?

Could it be too much heavy body and not enough light? Would that cause short preps?

 

[zero_zero]

The Dr. should've used a Trios...

 

[zero_zero]

On the serious note, prolly did some crown lengthening for esthetics and wants a new set of veneers for free, blaming you for ill fit...

 

[Patrick Coon]

tissue looks completely inflamed from cuspid to cuspid (notice puffiness around gumline and shortness of cuspids in first cast). He/she probably also should have used retraction cord before first impression like he/she did in second.

 

[rkm rdt]

tissue looks completely inflamed from cuspid to cuspid (notice puffiness around gumline and shortness of cuspids in first cast). He/she probably also should have used retraction cord before first impression like he/she did in second.

Interesting observation. The margins look ok in both impressions under the scope but not much retraction on either.
Not much light body on either impression.

 

[rkm rdt]

On the serious note, prolly did some crown lengthening for esthetics and wants a new set of veneers for free, blaming you for ill fit...

They should still fit although the margins would be short.

 

[MasterCeramist]

Who knows what they did on their end to get it distorted so many variables. It does look as though he did some refining on the preps as well.

 

[rkm rdt]

Who knows what they did on their end to get it distorted so many variables. It does look as though he did some refining on the preps as well.

The dr claims there was no refinement. If that was the case, wouldn't the preps be loose? They were tight.

 

[keroassidy]

The distal incisal angles of 8 9 in 1 do not match in 2. In 2 mesial distal incisal edges are straight across. Weird.

 

[CatamountRob]

I've had cases come back with a new impression and the first one looks similar, but shorter. I have always chalked it up to the impression being pulled too soon or something retarding the setting of the material and the suction pulling the material back on itself. I really don't know if it's possible, but that's the only way that I could see it happening.

 

[rkm rdt]

Check this out....no adhesive either.

 

[Patrick Coon]

The distal incisal angles of 8 9 in 1 do not match in 2. In 2 mesial distal incisal edges are straight across. Weird.

I believe that is just an optical illusion caused by each cast being at a slightly different angle from the camera lens.

crown lengths do look different though and second cast is definitely cleaner than first (preps look smoother.

If everything on the second fits well except the margins are short, I would say margins were mismarked or not visible on first cast. Or margins were extended and reimpressed.

 

[rkm rdt]

I believe that is just an optical illusion caused by each cast being at a slightly different angle from the camera lens.

crown lengths do look different though and second cast is definitely cleaner than first (preps look smoother.

If everything on the second fits well except the margins are short, I would say margins were mismarked or not visible on first cast. Or margins were extended and reimpressed.

The walls of #2 dies were tight .I can abrade the dies but they don't seat very well as if there was also lateral distortion .

 

[Affinity]

I was going to say that the first looks like the material did not lock into the tray, which would easily cause a large distortion. I dont like the trays with the larger longer holes. Although, this is a fairly large distortion as apparent by the distance between the preps even.. Doesnt look like the material came off the tray too much though.. hate sht like this.

 

[2thm8kr]

Inversion after pouring?

 

[CoolHandLuke]

How did impression distort?

easy.

assistant Wiggled it onto the preps and wiggled it off. second time this assistant learned you dont wiggle it unless you plan on being a stripper and pushed it on properly.

 

[Affinity]

on second look.. sorry if it was already mentioned. The medium/heavy body looks like hand-mixed putty. Maybe it wasnt mixed properly? You can see in the corner of the second one there is some white unmixed.

 

[rkm rdt]

Inversion after pouring?

I box every full arch with plastecine. Veneers were finished on master and also fitted to solid check model.

This dr did a thesis on the inaccuracies of Intra oral scanners.

 

[rkm rdt]

on second look.. sorry if it was already mentioned. The medium/heavy body looks like hand-mixed putty. Maybe it wasnt mixed properly? You can see in the corner of the second one there is some white unmixed.

Problem is #2 is determined to be the accurate one compared to the mouth.

 

[zero_zero]

Scan both models, align them...might shed some light on what went wrong...