Costech continues with its series of hints and tips giving you advice on when to use Bruxzir, an alternative to PFMs and full-metal crowns.
Bruxzir has fast become the favoured alternative to both PFMs (porcelain fused to metal) and full-metal crowns. The high strength of the material has made even knife-edge margins and sub-gingival all-ceramic restorations possible. Here are some tips and tricks of why, how and when to use Bruxzir.
Bruxzir is indicated for crowns, bridges, inlays and onlays. It is an alternative to PFM metal occlusal, lingual of full cast restorations and ideal for restorations requiring extra durability such as crowns under partials or screw-retained crowns.
Shoulder preparation is not needed for this all-ceramic restoration, featheredge is ok. Conservative preparations, as you would have for a full-cast crown, are acceptable as long as there is at least 0.5mm clearance (although at least 1mm is ideal).
Zirconia is a very hard material, as known to anyone who has seen the sparks it can produce. However, adjustments are simply down to technique.
For best results use a fine diamond on a medium to slow speed with a lot of water and a sweeping/grinding motion. A grinding action is far more effective than a cutting action with monolithic zirconia. Polish using diamond-impregnated rubber cups.
Always use a zirconia cleaner such as Ivoclean prior to bonding. This increases the bonding strength. Do not use phosphoric acid, as the phosphate groups bond to the zirconia receptor site, thus not allowing the cement to bond. Any resin-reinforced glass ionomer cement of your choice will bond.