Vinyl Polysiloxane (VPS) impression (Imprint 4 VPS; 3M ESPE) demonstrating very clear and distinct margins

Polyether impression (Impregum and Permadyne; 3M ESPE) also producing a clean, clear impression of the prepared teeth

Polymer model produced from a digital impression (True Definition Scanner, 3M ESPE)

CAD-CAM milled monolithic zirconia restoration (Lava, 3M ESPE)

After the crown has been tried in, the preparation is cleaned with a wet slurry of pumice (Preppies, Whip Mix) and 2% chlorohexidine (Cavity Cleanser, BISCO). The preparation is then thoroughly rinsed and briefly air-dried

After the crown has been tried in, and just prior to cementation, the intaglio surface is sandblasted with 50 micron aluminum oxide (Al2O3) at an air pressure of between 30-40 psi and distance of approximately 10 mm

One to two coats of a 10 MDP zirconia primer is placed on the sandblasted surface of the zirconia, according to manufacturer’s instructions. If a universal adhesive is used (such as Scotchbond Universal Adhesive, 3M ESPE), light cure after thoroughly air drying the adhesive

Dr. Alex prefers to use warm, dry air when evaporating the solvents from various zirconia and porcelain primers

In this case, the crown is filled with a self-etching and self-priming resin cement (RelyX Unicem 2, 3M ESPE)

Once the crown is filled, carefully rub a small amount of Vaseline or other lubricant in the interproximal areas, carefully avoiding the margins, to facilitate floss placement and removal of the set resin cement

When using a dual-cure resin cement, Dr. Alex allows these materials to self-cure initially until they reach a “hard rubbery” state. Resin-based cements are fairly easy to clean up at this point. Once they are light cured, clean-up – especially in the interproximal areas – can be extremely challenging. After the buccal and lingual cement is removed, the assistant holds the crown in place with an instrument while the dentist snaps floss through the interproximal contact and then “pulls” the floss (which has a square knot tied at the end) through the cervical embrasure. Done properly and timed well, this is an excellent clinical technique for resin cement removal

When using a dual-cure resin cement, Dr. Alex allows these materials to self-cure initially until they reach a “hard rubbery” state. Resin-based cements are fairly easy to clean up at this point. Once they are light cured, clean-up – especially in the interproximal areas – can be extremely challenging. After the buccal and lingual cement is removed, the assistant holds the crown in place with an instrument while the dentist snaps floss through the interproximal contact and then “pulls” the floss (which has a square knot tied at the end) through the cervical embrasure. Done properly and timed well, this is an excellent clinical technique for resin cement removal

After most of the cement is removed in the hard rubbery stage, the crown is irradiated from the occlusal, buccal and lingual, to optimize polymerization of the resin cement

Finished monolithic zirconia crown