Dental CAD/CAM in the Esthetic Zone – A Digital Veneer Case Study

Tuesday, June 25, 2013

Dental CAD/CAM in the Esthetic Zone – A Digital Veneer Case Study

As CAD/CAM dentistry expands its borders in private practice, the workflow around common procedures continues to change.

For example, with no need for a physical model, wax-up, or even delivery of the case to a dental laboratory a single crown can be fabricated in under an hour. There is no compromise of fit, strength or esthetics, and there is no need for a provisional crown.

This dramatically changes how your office schedules this patient, or even how you might collect a co-pay considering the restoration is completed in a single visit.

The traditional workflow for an anterior esthetic veneer case often utilized a wax-up, and provisional phase in which we were visually and functionally testing a smile design. There would be modifications to that provisional, and at some point we captured that look with an impression. That model was then sent off to the lab with a note saying, “the patient likes these embrasures, length, etc., so make it like this.” Three more weeks went by and we would finally have our veneers ready to go. The hope was that the try-in would go perfectly to avoid having to remake the provisionals or add another three weeks to the case for a remake at the lab.

Dental CAD/CAM technology has changed all of that. Below is a case we did in my practice recently that reflects the magnitude of this change.

A pre-op view of the patient’s teeth

The patient’s smile, pre-op.

A pre-op view of the patient’s teeth

A retracted pre-op view.

The patient was concerned about the color of her teeth, reporting childhood antibiotics contributing to the darker color. She had already been through a round of Invisalign in an attempt to correct crowding and rotations, but was unwilling to continue orthodontic treatment. Also, she could not tolerate whitening gel of any kind due to extreme sensitivity. The decision was made to place conservative porcelain restorations to do a final correction of tooth position, color and to eliminate “black-triangles” at the gingival embrasures. Considering the lip line, we did not need to address the uneven gingival profile.

The diagnostic wax-up

The wax-up veneer design.

Visit 1 – Wax-Up – We obtained alginate impressions, and did a diagnostic wax-up to “ideal” tooth position. Overall length was determined functionally, as well as the position of her lip.

The patient with provisionals in place

A retracted view of the provisional veneers.

Visit 22 days later - Both upper and lower arches were prepared for porcelain restorations. Contacts were broken in most cases to allow for a longer contact to eliminate black triangles. A final impression scan was done using the CEREC dental CAD/CAM system from Sirona. Provisional restorations were made using a clear stent from the corresponding diagnostic wax-up.

Visit 31 week later - The patient returned to verify final esthetics. We slightly altered the length and shape of the lateral incisors, as well as the overall incisal embrasure shape on all teeth. Without removing anything, we took a second digital impression with CEREC using the copy function. This allows us to exactly map the position of the provisional crowns to the preparations and captures all the esthetic changes she requested without any guesswork from a secondary alginate impression. The appointment took around 10 minutes.

The provisionals are copied in CEREC software

The digital copy of the provisionals.

The digital design of the veeners is checked over the preps

The veneer design over the preps.

The final digital restoration design

The final restoration design.

Visit 41 day later – Final design was completed using with the CEREC dental CAD/CAM software, and the IPS e.max restorations were milled in our office using Sirona’s MCXL milling machine. Considering the accuracy of a digital impression, the try-in took only a few minutes with almost no adjustments to contacts or occlusion. We cemented the veneers in place using 3M ESPE’s Scotchbond Universal Adhesive and RelyX Ultimate Adhesive Resin Cement resin cements.

A post-op view of the seated veneers

The patient’s smile, post-op.

A retracted post-op view of the veneers

A retracted view of the finished veneers.

The great thing about this case is that we were able to fabricate the entire thing in one day in our office rather than waiting three to four weeks for an outside lab. This improved not only the patient experience, but our bottom line as well.

We only had to take one digital impression of the preps, and that was done before the provisional crowns were made. And by using the copy function in the CEREC software, I knew we could exactly replicate the desired esthetics. Plus, if something didn’t fit right or broke at the try-in appointment, we could simply make the change in the software and mill another restoration.

For me there is no question that dental CAD/CAM technology improved the entire veneer experience for my patient and my practice.

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