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QUARTER 2 | 2014 | CERECDOCTORS.COM | 67
Terry Hulihan | Pinehurst, N.C.
Debonds usually happen in our heavy bruxers.
And sometimes, it happens in the same patients
more thanonceondifferent crowns.Most of these folks are in
group function, and they are beating thehell out of their teeth
all night long. It is hard to produce idealized occlusion on
these folks and they will find a way to load the teeth laterally.
Therefore, we tend to provide for more resistance formwith
parallel and longer axial walls. We have had these issues as
well, and we are super-careful with our bonding. We always
cement under a rubber dam or Isodry. Most of our debonds
occurredat theporcelainwith the toothentombed incement.
Sometimes you just gotta bite the bullet and re-prep ’em.
Charles LoGiudice | Geneseo, Ill.
I have not had many debonds but all of the ones
I have had have been on veneers and inlay/
onlays which were prepped with no resistance form,
relying on the bonding resin for 100 percent of the reten-
tion. According to everything you have shared, you should
not be having this problem. I have to conclude that there is
something you are overlooking or missing.
David Honey
Which sandblast are you using to etch or to
clean the object fix out? Also, I usually let the
monobond sit for a minute. (HOW old is the monobond?)
I have a couple of flat tops that have been in for years
withoutdebondwiththeMultilink.(BadbatchofMultilink?)
Justin Gates | Marion, Va.
When the debond occurs, is the cement on the
crown or on the tooth? This is critical to figuring
out where the bonding issue is occurring. The interface of
the cement-to-tooth (dentin/enamel) or the interface of
the crown surface and the cement.
Brian Toorani | Huntington Beach, Calif.
I have been using Multilink for a few years
with no debond. My guess is that maybe you
are getting some contamination underneath before the
cement is set. In other words, cleaning up too fast and
saliva and blood getting under (since all your other steps
are correct). I would change out your cements and mono-
bond for a new one and stick to it. Select etch the enamel
for five to 10 seconds, scrub in A and B for 30 seconds
minimum, seat crown, tack cure line angles for one to two
seconds, keep pressure on top of crown (I use a spoon)
when cleaning and flossing! Good luck and hope this gets
resolved for you!
BTW, make sure you dispense a full drop of A and a full
drop of B. We keep these bottles upside down and tap them
on table top to reduce bubbles and get a full drop!
Sandra Calleros | El Segundo, Calif.
I think it would be helpful to post a few cases to
have them analyzed for prep form.
David Edelson
I would imagine prep design may be an influ-
ence here as well. Are you getting some reten-
tion and resistance form in you preps? For my onlay/
crowns I still do a bit of a modified gold onlay prep. I don’t
flattenmy cusps as much as some may do. Three-hundred-
and-sixty-degree chamfer as well around and cervical to
the reduced cusps. Gives me more porcelain support and
more surface area to adhere to. If you’re comfortable with
it, throw a few prep pictures up and maybe someone can
determine if it’s prep-design related?
Gregor Sonin
Peroxide on prep prior to bonding = super-
nice oxygen inhibition layer between tooth and
bonding! Avoid that: just sandblast/pumice for cleaning
and proceed your bonding protocol.
Marc Thomas
The most important thing to remember is that
there is a fix here, we have just got to figure it out.
There is some contamination or gross procedural error
occurring with the adhesive step. In 18 years of practice
with a huge bias toward bonded restorations, I have never
had more than a handful of debonds in any given year.
Even a perfectly flat, zero-retention crown bonded to a flat
stump of tooth should hold on for quite a while before the
bond fails.