We’re human, and we make mistakes. When it happens, we sometimes need to stop and start over to fix the situation. Yet, every once in a while, a mistake can turn into a lucky strike. You know how they say: “every cloud has a silver lining!”.
This young girl came to the office a couple of years ago, complaining about the dark appearance of her upper right central incisor. The tooth was root canal treated, completely asymptomatic, and the x-ray showed a well done treatment. So we decided to go on with a walking bleaching procedure. The bleaching worked, and the patient was satisfied. Unfortunately, a couple of months ago the patient came back, complaining about a complete relapse. The tooth just went back to the old dark color.
The patient was asking for a more stable solution, so we decided to proceed with a feldspathic ceramic veneer on tooth 11.
Single tooth veneers are always a great challenge for the lab technician, especially when the tooth is discolored.
It’s very hard to manage the discoloration in a very small thickness, so the technician usually asks for a more aggressive preparation. CDT Pasquale Casaburo and I talked a lot about this case, in order to find a good compromise between the need for space, and the will to prepare as little as possible, and to stay on enamel with the preparation.
To make sure the patient was aware of the possibility, I proposed to close the little diastema she had in between the incisors, but she refused.
Fig.1
The initial situation. The discoloration and some crack lines are clearly visible.
Fig.2
The smile of the patient.
Fig.3
Since the tooth didn’t need any shape modification, there was no need for a waxup and a mock- p. A precision impression with a VPS (DMG Honigum Pro) was done in order to create a direct temporary restoration after the preparation. It is very important to have an accurate, stable and reliable impression to do so.
Fig.4
The VPS impression.
Fig.5
Depth grooves are essential to have a calibrated preparation, but we need to use the bur correctly. If we don’t use the neck of the bur as a stop, we have absolutely no control over the depth of the grooves.
Fig.6
We need to know the diameter of the bur (D1), and of the neck (D2). So the difference between D1 and D2, divided by 2, is the actual penetration on the bur (D3) if we use it correctly. We must also respect the different inclinations of the buccal surface, changing the orientation of the bur from cervical to incisal.
Fig.7
3 different inclinations of the bur to make the depth grooves (A: cervical B: middle 1/3 C: incisal).
Fig.8
The grooves on the buccal surface.
Fig.9
The 3 grooves were connected respecting the 3 different inclinations of the buccal surface.
Fig.10
A retraction cord was used to displace the gum.
Fig.11
The Zekrya gingival protector was then used to increase the retraction and to protect the gum.
Fig.12
With a fine grit diamond bur, the preparation was finished and the cervical margin was moved apically.
Fig.13
Silicone keys are very helpful to check the thickness of the preparation.
Fig.14
It’s extremely important to give to the lab indications about the color of the preparation, especially when requesting a veneer restoration.
Fig.15
A thin (000) and a thick (0) retraction cord were positioned in order to expose the intrasulcular space for the final impression.
Fig.16
A low viscosity VPS (DMG Honigum Pro Light) was distributed all over the preparation and on neighboring teeth.
Fig.17
The impression was then taken with a heavy VPS (DMG Honigum Pro Heavy) on a custom tray.
Fig.18
Close-up of the impression; note how impressive is the detail read by the material.
Fig.19
The first impression was then filled with a self-curing resin material (DMG Luxatemp Star) in order to create a temporary restoration for the prepared tooth.
The temporary phase is always tricky in veneers cases, especially in single tooth management. I always try not to use adhesive to stabilize the provisional, because it would be quite hard to perfectly remove it without removing tissue, losing some of the precision of the restoration. In single teeth cases it is extremely important to use a strong and stable material that can ensure stability just by penetrating in the undercuts of the interdental areas. We also need high aesthetics, and a bright and easily polishable surface for a central incisor.
Fig.20
The appearance of the temporary restoration. Of course, it’s impossible for such a low thickness of resin to completely cover the discoloration, but the result was good and very easy to obtain.
Fig.21
After 2 weeks the provisional veneer was removed.
Fig.22
And then we realized the mistake. The lab technician completely forgot about the indication to maintain the diastema and closed it. The increasing on width was so small that the difference between the 2 incisors was not so visible, but I immediately apologized to the patient for the mistake and gave her a mirror to explain what happened. I was already planning a solution: the first attempt would have been to use a diamond disc to remove some ceramic. The second would have been to send back the veneer to the lab to better handle the modification.
But every cloud has a silver lining, and the patient surprised me saying that she liked the new shape. So, we decided to go on with the cementation.
The chromatic trial was done using a try-in paste (DMG Vitique Try-in col. B1).
Fig.23
Rubber dam was placed, and a 212 clamp was used to maximize isolation.
Fig.24
The veneer was etched with hydrofluoric acid for 60 seconds (A), then carefully washed and dried. After that, a thin layer of silane (DMG Vitique Silane) was applied (B) and then dried.
Fig.25
37% phosphoric acid gel (DMG Etching gel) was applied for 30 seconds all over the preparation, then washed and dried. Neighboring teeth were protected with teflon tape.
Fig.26
Classic appearance of etched enamel.
Fig.27
A dual-cure universal adhesive (DMG Luxabond Universal) was applied on the silanized ceramic and was then air-dried.
Fig.28
The same adhesive was applied all over the prepared surface and air-dried.
Fig.29
An aesthetic resin cement (DMG Vitique B1) was applied on the veneer.
Fig.30
The veneer was carefully applied, resin excess was removed, then everything was light cured.
Fig.31
A #12 blade is very helpful to remove excess cement.
Fig.32
The appearance after rubber dam removal and careful finishing and polishing.
Fig.33
Ten days check-up. The patient was completely satisfied with the veneer. She said we had been lucky to find a mistake that, in the end, was an improvement!
Gums looked healthy, and the veneer very well integrated with patient’s natural teeth.
Fig.34
The new smile of the patient.
Fig.35
Before and after.
Conclusions
Benjamin Franklin said: “if you fail to plan, you are planning to fail”. We always need to focus on a correct diagnosis, and then chose the best treatment plan for our patient. Even if we are really focused, mistakes can happen! This time we were very lucky. A misunderstanding, or maybe an inaccuracy in the lab phase, turned up to be an improvement very appreciated by the patient.
Bibliography
1.Koubi S. Laminate veneers. 2020 Quintessence.
2.Magne P, Magne M. Use of additive waxup and direct intraoral mock-up for enamel preservation with porcelain laminate veneers. Eur J Esthet Dent. 2006 Apr;1(1):10-9.3.
3.Galip G. The science and art of Porcelain Laminate Veneers , London, Quintessence, 20034.
4.Gürel G. Porcelain laminate veneers: minimal tooth preparation by design. Dent Clin North Am. 2007 Apr;51(2):419-31, ix.
