Rich Rosenblatt Our faculty member, Dr. Rich Rosenblatt, on behalf of Peter Golden with 3M in regards to bonding with Lava Ultimate.
To reiterate, there are really 5 key areas to emphasize when bonding Lava Ultimate.
Prep design-- should be as retentive as possible. It's obviously not always possible to produce text book preps, especially when removing restorations/re-prepping previously restored teeth, but creating better retention is frequently possible if we can create some opposing surfaces.
Pretreatment of the restoration (intaglio surface) - in the case of Lava Ultimate, air abrade to gain the best micro mechanical retention. HF etch will not do it for Lava Ultimate.
Etch the tooth surface-- selective or total etch is necessary to provide micro mechanical properties; total etch, especially if the prep is not very retentive. Bonding of full coverage (crowns) benefit by this. This is the call of the clinician, but this is an instance where more (micro-mechanical retention) is better.
I would like to re-emphasize that light curing the Scotchbond Universal Adhesive on the TOOTH SURFACE prior to seating does provide at least some greater initial bond strength- Again, this should be helpful when bonding full coverage. The very thin film thickness of of the Scotchbond Univ. will not hold up the restoration if excess material is blown off (look to see that no adhesive is moving on the tooth structure)--then light cure. Don't try light curing the adhesive on the intaglio of the crown-- this adds nothing to the equation, and can potentially provide enough thickness to hold up a crown.
Finally, make sure to hold the restoration in place firmly when cleaning up using a tack and flick style; you can not always see if a very slight dislodging may have occurred. Regardless of bonding products that you are using clinically-- read the instructions and use the material as the manufacturer has intended. After all, they've tested these chemistries, and they have determined that this is is how they work best! --hope this is somewhat helpful....
