When you get burned by being too conservative
I treated a patient today that I thought would be a good learning case for everyone...
This 55 year old lady came to my office with veneers that were done 3 years ago. She had them done all at the same time, but was unhappy with 3 things:
- Color discrepancy between 8 and 9
- 9 was shorter than 8
- 9 had chipped and been repaired with composite
Here is her preop photos
Our plan today (due to finances) was just to replace 8 and 9 and solve her primary concern. I talked her into doing #7 and 10 over again as well later in the year because the inclination of #10 is wrong. I also used e.max MT because her wear on the lower teeth indicated bruxism and the probably caused the chipping.
After removing the ceramic on #8 and #9 I noticed the issue with the color discrepancy. Now, since she had them done at the same time, I can only assume that they were made out of the same exact material.... so why the color discrepancy?
As you can see from the photo, #8 was prepared more for a full coverage crown (3/4) and #9 was prepared for a super conservative veneer. The problem with this is that it created a major discrepancy in porcelain thickness...which affected the overall value and translucency difference between the two teeth. This is a major lesson to be learned. We always concentrate on symmetry of the centrals, but you also have to have symmetry of the preparations to get the best results with CEREC.
So we reprepped the teeth so that the thickness of the ceramic will be the same on both...
Here are the final "new" crown just with try in pastes before final finishing and polishing. I will post the finals at the healing check appt in a couple weeks. You can see the color and translucency is now similar between the two teeth.
PREP IS KEY!
I've definitely made this mistake as well. Always trying to be conservative, but you have to prep with the final results in mind!
inclination of #10 is wrong.
Hi Mike, Thanks for posting the case. Could you elaborate on the above comment? I do not understand what you mean.
Thanks
Nice. That case initially was lost only after cementation and the dentist, assistant and patient said "Oh sh*t" and did not understand how the same shade ceramic would lead to that result. Great lesson. Nice preps.
What if the teeth position were not ideal, lets say hypothetically #10 was more lingual than the centrals, the thickness of ceramic would be more on the lateral than it would be in the central, how do you compensate for that while keeping the preparation on the other teeth minimal?
I'll take a stab at this. #10 is positioned too far to the labial and the disto-labial line angle is too prominent. It does not look like mother nature usually makes her maxillary lateral incisors.
On 10/21/2015 at 5:20 pm, Charles LoGiudice said...I'll take a stab at this. #10 is positioned too far to the labial and the disto-labial line angle is too prominent. It does not look like mother nature usually makes her maxillary lateral incisors.
As Mike has said at his lectures: the maxillary anteriors need to point to the belly button ....
Winnie
Karen, to respond to your hypothetical question, I would think that overly thick ceramic wouldn't be nearly as big of a factor as too thin.
Never put the immediate pic ... not try in paste. Will post the healed later when I do 7 and 10. Love the MT
The original shape/angle of the two teeth, or decay may have required the deeper prep on #8. You're right--sometimes we get caught up in the moment and forget this important fact.
Thanks for the reminder of the need for symmetry in prep design. Lovely case!
Mike,
what is your opinion on the gingival height between 8 and 9?
do you think it could have grown if the contacts were not that long or would you have ended up with a dark triangle?
I am thinking not the lines of contact length: gingival zenith to papilla height ratio.
On 10/31/2015 at 3:20 pm, Dhaval Patel said...Mike,
what is your opinion on the gingival height between 8 and 9?
do you think it could have grown if the contacts were not that long or would you have ended up with a dark triangle?
I am thinking not the lines of contact length: gingival zenith to papilla height ratio.
Hi Dhaval-
Look at this picture that was posted. It will give you a clue as to what is going on:
The papillae height is going to be 100% determined by the bone (biology). If you look at the occlusal pathology and attrition on her teeth, it will clue you in on what is happening. Here gingival heights preoperatively ware all off. The Canines and laterals are in the proper position, but the centrals have erupted. In my experience, the eruption of central incisors and alveolar bone growth associated with it tends to "blunt" the papilla a bit... meaning, the interproximal and buccal bone do not move coronally symmetrically.
This was discussed with this patient prior to treating this case. I gave her 3 options based on what I saw:
- Restoring 7-10 with crown lengthing procedure on 8 and 9. This I think would have solved what you were looking for. The incisal length of the teeth is correct...meaning that the attrition on 8 and 9 and 23-26 happened in a way that allowed symmetric eruption of the teeth. Therefore, I think the papillae heights are also in the correct position. By crown lengthening, you would keep the incisal length and papilla height the same, but the "longer tooth" would have indirectly created a more scalloped longer papillae at the midline.
- Orthodontics and restoring 7-10 and 23-26. If she wanted to do the lowers as well, she would have needed to do ortho to intrude 23-26 and create room. I would have intruded 8 and 9 at the same time. This gets a little tricky to intrude teeth and maintain interproximal bone, but it can be done. An alternative and likely easier scenario would have been ortho AND crown lengthening.
- Restore her teeth in the current position and accept the blunted papillae and gingival crest discrepancy...Because she is going to continue to do what she has been doing to her teeth, you have to give her some sort of protection via guard, etc..
She chose 3 because here only concerns were the chipping of the veneer #9 and the color discrepancy of #8 and #9 so that is what we did.
To answer your question... No I do not believe we could have had a much shorter contact length and I do believe doing it would have resulted in a black triangle. The bone is where it is and the eruption blunted the papillae.
Hope all this make sense. Let me know if you have any questions.
