old metal ceramic crowns on lateral incisors

Case of two anterior restorations with full contour Multilayered Zirconia

Sometimes prosthetic solutions that once were the state of the art become unacceptable for patients. This patient, for example, came to replace his old metal-ceramic crowns on his lateral incisors.

provisional resin crowns on lateral incisors

Fig.1

As a first step, two provisional resin crowns were fabricated and used as a prototype

digital model and abutment scanning

Fig.2

Then we prepared the abutments and took an impression, and the model was then scanned.
In the picture you can see the buccal and palatal views of preparation on the master model.

digital CAD project for zirconia crowns

Fig.3

For this case we made a CAD design project, which palatal and buccal views you can see in the picture, after occlusion and virtual check.

CAD thickness check

Fig.4

Also the CAD design thickness was checked, in order to comply with material prescriptions and soft tissue health, while keeping preparations as conservative as possible.

CAD modeling for natural appearance

Fig.5

It is very important to replicate a natural morphology, in order to create a correct design also respecting soft tissues.

rubber contouring of zirconia crowns

Fig.6

After sintering and checking the zirconia crowns on the model, it is possible prepare the surface with a fine grain rubber to reduce the margin line off-set and finish surface texture.

sandblasting of zirconia before staining

Fig.7

Sandblasting was carried out with aluminum oxide 50 micron particles, at 1.5 atm.

staining of zirconia crowns for a natural effect

Fig.8

The staining technique allows us to increase the chroma and the value effect of the enamel.

finished zirconia crowns

Fig.9

In the picture, you can see the final result after baking.

polishing palatal surface for perfect gloss of the crown

Fig.10

After a couple of staining steps you can improve texture and gloss with a diamond paste or an extra-fine diamond rubber. Polishing perfectly is also important to obtain a non-abrasive surface.

palatal view of prosthetic zirconia crowns

Fig.11

Here you can see the final result after palatal mechanical polishing.

zirconia crowns on lateral incisors after luting

Fig.12

And the amazing result after cementation.

polarized picture for color check of zirconia

Fig.13

The polarized filter is very useful for an accurate, final color check.

Conclusions

The new generation zirconia materials allow us to accomplish highly aesthetic results in the anterior area by applying a single-layer conservative approach.

Credits

The clinical part of this case was performed by Walter Devoto.

Bibliography

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4. Piconi C, Maccauro G. Zirconia as a ceramic biomaterial. Biomaterials. 1999 Jan;20(1):1-25. Review.
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