Fig.1
After crown removal, endodontic treatment and build up were needed in order to proceed with tooth preparation and prosthetics. In the picture you can see how the abutment looked after removing the old crown.

Fig.2
Although a chamfer preparation could still be performed on this tooth, since clinical and anatomical crown coincide, meaning previous tooth preparation is still supragingival and we could still prepare the chamfer juxta-gingival, a vertical preparation was chosen to better control soft tissue contour.

Fig.3
Isolation of the abutment right before build-up.

Fig.4
Tooth abutment build-up.

Fig.5
With deletion of the pre-existing finishing line and controlled invasion of the sulcus we can create space for biotype conversion (soft tissue thickening). The clinical and biological advantages in achieving a thick biotype are:
Stabilization of soft tissues
Reduction in gingival color changes
Better esthetics

Fig.6
The temporary crown was relined following the biodynamic soft tissue shaping concept.

Fig.7
The temporary crown is key to achieving gingival thickness and gingival margin stability. The margin of the temporary crown becomes the new prosthetic CEJ for new gingival forms and profiles (biodynamic soft tissue shaping). After finishing of the margin, the provisional crown was cemented.

Fig.8
Temporary crown after cementation.

Fig.9
After 1 month tissue conditioning, we were ready for impression.

Fig.10
Monolithic zirconia crown with super polished zirconia margins.

Fig.11
Monolithic zirconia crown with super polished zirconia margins.

Fig.12
Final result.

Fig.13
Before and after.

Conclusions

Vertical tooth preparation becomes a powerful tool in achieving esthetics. The finishing line is the crown margin itself, and, from day 0, right after tooth preparation, we can manipulate soft tissues with the temporary crown. After one month, soft tissues are thicker and ready for final impression and crown.
Moreover, choosing the right material for the dental crown is important, since the margin of the final crown is the landing zone for soft tissue stability. Although there are different opinions on optimal material choice, it cannot be denied that zirconia as a material offers substantial advantages over other choices, due to lower adhesion of bacteria, less inflammatory response in soft tissue and esthetics.
Final positioning of the crown margin is 0.5 mm apical to free gingival margin, and biocompatibility is higher when utilizing zirconia.
However, the response of the soft tissue might not only depend on the type of material, but also on the polish degree of the material’s surface. That’s why it is important to have a super polished margin for long term soft tissue stability.

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