Rich Rosenblatt Last week on the message boards, a doc was having an issue with debonds using the new Lava Ultimate material.
Lava Ultimate is a promising new material, but it is not the same as ceramic when bonding them in. It is classified as a nanoceramic and has a slightly different bonding protocol. I'm posting an excerpt of the discussion where I discussed with some of the people at 3M the do's and don’ts when bonding in the Lava Ultimate material. The do's and don'ts are standard but I have included a chart from 3M on how to treat the restoration when specifically using their products. Here is what we posted on the thread:
First and foremost, make sure you are using a bonding agent that is recommended for indirect restorations. Also, make sure that you are using some form of complete isolation like Rubber Dam or Isolite. They also said that they have a long history of successfully using Unicem with older restoratives like MZ 100. Although Ultimate is a different material than MZ 100, the elastic modulus is similar and there should be no link between the "flexing" of the crown and debonding.
PRE-TREATMENT OF THE RESTORATION: DO’S AND DON'TS
DO:
1.) Sandblast or air abrade with alumina. Use material with less than 50 micron particle size. Use low pressure (2 bars/30 psi).
2.) Clean the internal surface of the restoration with alcohol and dry the restoration
3.) Depending on bonding agent and cement you select, apply appropriate primer/bonding agent. (3M's Unicem 2 does not require a primer/bonding agent) If you are using the new Scotchbond Universal bonding agent, the silane is in the material. Just apply the Scotchbond universal to the intaglio and air dry. Do not cure it – it is ready to go.
If you are not using Scotchbond, then you should definitely use silane. Most silanes have a short shelf life, so be sure that the silane is fresh. Using no silane or old, degraded silane will definitely lower bond strength.
Why is this step done? To improve retention/adhesion and ensure the surface is free of contamination from milling debris, milling fluids, saliva during try in and grease.
DON’T:
1.) No acid etch on internal of restoration. No HF or Phosphoric
TOOTH PREPARATION DO'S AND DON'TS:
DO:
1.) Mechanically clean the tooth to remove contamination. This can be achieved with a brush, pumice slurry or bur.
2.) Rinse with water and slightly air dry. Surface should appear glossy. (Most bonding systems do not want you to completely dessicate the tooth. When using a bonding agent like Surpass, you are told to completely dry the tooth.)
DON’T:
1.) Don't use other chemical agents such as hydrogen peroxide, EDTA, bicarbonates, astringents (drying agents), or chlorhexidine
2.) Do not Laser etch.
Desensitizers are not necessary with Scotchbond Universal. They are incorporated into the bonding agent. It would be considered a redundant step. Their testing does show that Gluma is not detrimental and DOES NOT weaken the bond. They said that they can't speak for other manufacturers but they can't imagine that would create that much of a negative effect on bonding.
Here is a snapshot of how to specifically use the different 3M bonding agents and cements with Lava Ultimate:
If you would like to read more about this topic, or ask any specific questions regarding this material and cementation of it, check out this thread py copying and pastuing this url into your browser:
