CAD/CAM

[Drsumitra]

My lab tchnician is working with Bruxzir….just an article i found to try and understand this system

 

What is BruxZir?

BruxZir® Solid Zirconia is a monolithic solid zirconia restoration with no porcelain overlay. More brawn than beauty, you’ll be impressed by the esthetics of BruxZir when prescribed instead of posterior metal occlusal PFMs and full-cast metal restorations. BruxZir is virtually chip proof, making it the ideal restoration for bruxers, implant restorations and areas with limited occlusal space.

BruxZir Solid Zirconia crowns & bridges are made from the highest quality zirconia powder from Japan. We chemically and physically reprocess the powder to further reduce the zirconia particle sizes. BruxZir milling blanks are then created through a unique patent-pending process. Unlike conventional high-pressure milling blank manufacture, our processing gives BruxZir improved light transmission, which provides a lower, more natural shade value.

Designed and milled using CAD/CAM technology, BruxZir is sintered for 6.5 hours at 1,530 degrees Celsius. The final BruxZir restoration emerges nearly chip proof and is glazed to a smooth surface.

Indications

BruxZir Solid Zirconia is indicated for crowns, bridges, implants, inlays and onlays. It is an esthetic alternative to PFM metal occlusal/lingual or full-cast restorations. The chip proof durability of BruxZir is ideal for bruxers who have broken natural teeth or previous PFM restorations. BruxZir is also ideal when the patient lacks the preparation space for a PFM.

Patient Benefits

Chip-resistant, as it is made of solid zirconia with no porcelain overlay
Glazed to a smooth surface to reduce plaque accumulation
Preparation Requirements

Shoulder preparation not needed, feather edge is okay. 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.
Instructions for Adjusting and Polishing BruxZir Crowns & Bridges

Adjust BruxZir Solid Zirconia restorations using a fine-grit diamond with light pressure to avoid potential microfractures. The specially designed Axis Dental BruxZir Adjustment & Polishing Set (LS-7579) may be purchased through your dental dealer or by calling 800-355-5063 .

A football-shaped bur is most effective for adjusting the occlusal surfaces of posterior teeth and lingual surfaces of anterior teeth.
A tapered bur is most effective for adjusting proximal contacts.
A round bur is used to adjust a cusp or fossa and for creating endodontic access.
Technical Update: Download Instructions
Technical Update: Do Not Use Discs To Finish Full-Contour Zirconia
Cementation Recommendations

Ceramir® Crown & Bridge (Doxa Dental; Newport Beach, Calif.) or a resin-reinforced glass ionomer cement such as RelyX™ Luting Cement (3M ESPE; St. Paul, Minn.) or GC Fuji Plus™ (GC America; Alsip; Ill.)
For short or over-tapered preparations, use a resin cement such as RelyX™ Unicem (3M ESPE) or Panavia™ F2.0 (Kuraray; New York, N.Y.)
Instructions for Seating BruxZir® and Other Zirconia-Based Crowns & Bridges

BruxZir restorations are fabricated from solid zirconia oxide material, much like the zirconia oxide coping found in restorations such as Prismatik Clinical Zirconia™, Lava™ Zirconia (3M ESPE; St. Paul, Minn.), and NobelProcera™ (Nobel Biocare; Yorba Linda, Calif.). Like most metals, zirconia exhibits a strong affinity for phosphate groups, and zirconia oxide is no different. We can take advantage of this fact with phosphate-containing primers, such as Monobond Plus (Ivoclar Vivadent; Amherst, N.Y.) and Z-Prime™ Plus (Bisco; Schaumburg, Ill.), or cements such as Ceramir® Crown & Bridge (Doxa Dental; Newport Beach, Calif.). Unfortunately, saliva also contains phosphates in the form of phospholipids, so when a BruxZir crown or bridge is tried in the patient’s mouth and comes in contact with saliva, the phosphate groups in the saliva bind to the zirconia oxide and cannot be rinsed out with water. Attempting to use phosphoric acid (which is full of phosphate groups) to "clean" the saliva out only makes the problem worse.

The only way we have found to successfully remove these phosphate groups from the interior of a BruxZir restoration is with the use of Ivoclean (Ivoclar Vivadent). This is a zirconia oxide solution placed inside the restoration for 20 seconds and then rinsed out. Due to the large concentration of free zirconia oxide in the Ivoclean, it acts as a sponge and binds to the phosphate groups that were previously bound to the BruxZir restoration. Once the Ivoclean is rinsed out, you will have a fresh bonding surface for the Monobond Plus, Z-Prime Plus or Ceramir to bond to.

The protocol would be:

Try in BruxZir or zirconia-based restoration.
Rinse saliva out of restoration.
Place Ivoclean in restoration for 20 seconds and rinse.
Cement restoration with Ceramir –or– place Monobond Plus/Z-Prime Plus and place with cement of your choice