Shoulder preparation not needed, feather edge is OK. It is a conservative preparation similar to full-cast gold, so any preparation with at least 0.5 mm of occlusal space is accepted. Minimum occlusal reduction of 0.5 mm; 1 mm is ideal.
These illustrations show an ideal 1 mm reduction for an anterior or posterior BruxZir crown, and also have feather-edge margins. BruxZir does fine at 1.5 or 2.0 mm as well, but this amount of reduction is not always possible. By maintaining 1 mm of BruxZir thickness, this allows you to safely adjust the crown if necessary when checking the occlusion. While BruxZir can be milled as thin as 0.5 mm, it cannot be adjusted at this thickness without breaking at some point. With a BruxZir crown at 0.5 thickness with high occlusion, consider adjusting the opposing tooth.
Typical Prep with PFM Crown
This image represents the typical PFM prep we receive with a conservative feather-edge margin. When a PFM is fabricated for this prep, is a bulky 1 mm margin on the PFM that catches on the explorer. Even if the margin is sealed, the emergence porofile is unacceptable.
Typical Prep with BruxZir Crown
This image represents the typical PFM prep we receive with a BruxZir crown in place. Because it is a monolithic crown and can be milled to a feather edge, there is no bulk of material, or "speed bump," at the margin. Dentists tell us their explorer cannot detect where the tooth ends and the BruxZir crown begins.
BruxZir Before & After Case
Case 1 Continued
This is much more difficult to achieve with bilayered restorations such as porcelain-fused-to-metal or porcelain-fusedto- zirconia. Since a BruxZir zirconia restoration is monolithic (one layer), it is much easier to achieve desirable contours.
This patient had a number of existing PFM restorations in the anterior, but tooth #8 and #9 had a previous rooth canal and a lingual fracture next to the access openings. It was decided that the best option was a full-coverage anterior BruxZir crown.
The patient presented with a fractured Maryland bridge. He ruled out implants because it would require a large bone graft. Instead, a digital impression was taken to fabricate a conventional BruxZir bridge.
As you can see in the "after" photos, the BruxZir bridge has acceptable esthetics, although it won't be mistaken for IPS Empressฎ anytime soon. Because BruxZir restorations are vitually unbreakable and the patient had already broken two PFM bridges in the past, this was the most appealing solution.
This female patient presented with a predominately cast metal bridge, which her dentist prescribed after she fractured the porcelain on each of the abutment teeth on the previous restoration. The patient always disliked how it looked and desired a more esthetic, long-term option. Because her PFM restorations had fractured previously, a high-strength BruxZir bridge was prescribed, providing the patient with the best combination of strength and esthetics.
When this patient required an onlay to replace a broken cusp, cast gold was suggested, but the patient declined. A BruxZir crown was used instead due to its impressive strength.
This patient factured a porcelain all-ceramic crown on the second molar and chipped the first molar. Both crowns were replaced with BruxZir crowns.
The patient had always disliked the metal occlusal on this PFM. When it became necessary to replace it, a tooth-colored BruxZir crown was chosen.
This endodontically treated molar had a large amalgam and several fractures, necessitating a full-coverage BruxZir crown.
This PFM crown had undergone chipping on multiple cusps and the mesial marginal ridge, resulting in an open contact. To prevent this from happening again, high-strength BruxZir Solid Zirconia was prescribed as a replacement restoration.
Information from BruxZir Clinical & Scientific Documentation and Hexa ceram dental lab