Page 71 - CEREC Q2 | 2014

QUARTER 2 | 2014 | CERECDOCTORS.COM | 69
Colin Fisher | Johannesburg, South Africa
Studies have shown that sandblasting dentine
have a negative impact on bonding. Also,
applying bonding agents when using Unicem is contra-
indicated. I’m not sure why it’s necessary to place temps
with CEREC. I understand powder can be a problem with
bonding issues.
Lindell Kemmet | Minot, N.D.
Agreewith Rich. I saw this post before boarding
a plane and was going to reply, but Marc obvi-
ously nailed what I would have said.
I will reiterate these:
• isolation
• fresh dentin
• AB SCRUB for 30 seconds ... scrub!
• oil contaminants in handpiece or inDentatech (in crown
for try-in)
• water in lines
Great posts, fun to see everyone trying to help!
Brent R. Browning | Houston
We all have an occasional debond even if the
before-mentioned criteria for success are met
100 percent. But, also purchase the best curing lights
out there. 3M ESPE and Ivoclar have great ones. In my
“Cadillac” op, I almost never have debonds with my best,
most expensive curing light. Need to buy a fewmore!
Charles LoGiudice
I agree with everything Rich has posted, with
one exception. Sam teaches that a smoother
prep is more retentive for bonding ceramic than a rough
prep. I agree because a smoother prep allows for a closer
fit and a rough surface doesn’t really improve the quality of
the surface etch which is the real source of the mechanical
retention of our restorations, so I run a fine grit diamond
lightly over my preps before imaging. Ivoclar preaches not
to sandblast the ontaglio of a restoration, and they make
no exception for air abrasion, which is done under lower
air pressure than sandblasting. Sandblasting weakens the
restoration and will result in a much weaker bond. Having
a nearbyMentor or “C” Trainer in to observe your protocol
is a great suggestion.
Sandra Cove
Hi everyone thanks for all of your comments.
This has been a problem for a long time. But
now have started to redo. I do most of my deliveries at the
same visit. But, with one assistant, I have found it chal-
lenging. Problem solved there — got two now.
It just dawned on me that the cement is always on the
crown and rarely on the tooth. When I said I used zone, I
was incorrect. I usually use Durelon with a little Vaseline
to make the removal easier. THIS may be the error!!!
I always shake the bottles. I have taken pictures and will
post them as my frustration is that high. But I think it is
the Vaseline!
I have heard two rules of thought. Only sandblast, do not
etch. Then I hear etch, don’t sandblast!
Which is the best? Right now I am sandblasting to make
sure any saliva or oils or anything that possibly could have
contaminated the tooth is removed. I have stopped etching
this past week, and just doing A and B. Bought a timer to
make sure we are following the Muiltilink rules to a “T”.
I have started re-prepping. I have had two e.maxes
fracture on second molars. That is a picture I can post. I
assume it was not thick enough. I got it to 1.5 and am doing
it in Enamic now.
What is the best way to get the Vaseline off of the cases I
have to deliver next week?
I cannot thank you for all your support. I have rackedmy
brain on this!!
Rich Rosenblatt (Faculty)
The Vaseline is most definitely a big issue and
likely what is causing this. I’m not sure how to
get that off. You can try alcohol.
Marc Thomas
Parkell sells some sort of a solvent-based
tooth cleaner. I would just use pumice and
Consepsis, or Consepsis scrub. I know the Consepsis has
a bunch of ETOH in it; I assume the scrub does as well.
Etch versus air abrade: are you asking about the tooth
or the crown? Either way, skip the air abrade. Etch the
crown with HF etch the tooth with phosphoric, total or
selective if you wish.
Get a trainer in to the office. If it costs you a couple grand,
it is cheaper than lost patients and replacing crowns.