POINT/COUNTERPOINT
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Do you take a bitewing at the crown seat appointment?
A Townie discussion from www.dentaltown.com
hudley
Saginaw, MI
Posts: 959
Reg.: 9/18/2002
david_f
Connecticut
Posts: 2,908
Reg.: 9/12/2000
jefftonner
Dental Malpractice
Defense Attorney
Phoenix, AZ
Posts: 286
Reg.: 5/30/2001
hudley
Saginaw, MI
Posts: 959
Reg.: 9/18/2002
Posted: 1/11/2003 9:46:00 AM
Post 1 of 115
Greetings Townies, I’ve not heard mention of this topic before and I’m interested to know if
there is consensus. I take a bitewing radiograph routinely at crown seating to verify that my
interproximal margins are closed. Is this common practice? I don’t remember learning this in
dental school. In fact, I learned it from my dad when I got out of dental school. Not only
does it tell you that the margins are closed, but it’s a record of the crown at the time of
seating. Does anyone else have a different way of verifying interproximal margins? Does
anyone find this technique to be overkill? Finally, do you charge for this radiograph, or is that
part of your fee?
Posted: 1/11/2003 10:17:00 AM
Post 3 of 115
Always. Many years ago I was concerned about excess radiation but when I got a few checkups and found out a perfect looking crown had an open or short margin I decided it’s worth
it. Considering how fast other dentists are to criticize, I’d like to know what it looks like
before I cement and not have to decide is a defect worth cutting off a year later. I don’t
charge for the BW, it is part of the crown.
Posted: 1/11/2003 10:36:00 AM
Post 4 of 115
I’ve seen it exonerate many a DDS! While a post-seating BW only shows the interproximal
margins, and not the buccal or lingual, it is evidence that a DDS has taken that extra step to
ensure that s/he did everything possible to secure a proper seal. The theory goes that if a
DDS is this careful, then s/he must have done the other steps properly as well. It mainly
creates the appearance of a careful DDS. I have never seen a DDS charge for it separately.
Posted: 1/11/2003 10:48:00 AM
Post 5 of 115
I always kind of looked at the seating bitewing as another part of the “checklist” that I keep
in my head. Interproximal contacts, occlusion, BW, etc. I haven’t ever charged for it either,
just like I don’t charge for the floss I use to check interproximals!
OK, now what do you do for an all-ceramic crown? Might a bitewing be less diagnostic in
this case? Also, do you take an “anterior bitewing” for anterior crowns or is a PA more
appropriate?
Rod
Mission Viejo, CA
Posts: 4,000
Reg.: 3/17/2000
Posted: 1/11/2003 7:14:00 PM
Post 10 of 115
I think it is GREAT PRACTICE to get a film each time...but I don’t do it. There is the
‘practical’ aspect to also consider. My approach is if I can feel the entire mesial and distal
margins, from both the buccal and lingual, then I don’t take a film. Being able to slide the
explorer over the margin is more accurate than a radiograph. Remember, radiographs take
straight-line pics, but roots have concavities, irregularities, and cervical burnout (artifact on
the radiograph in areas where tooth structure is less dense due to physical dimensions). But
there is something to be said about the legal ramifications.
Continued on page 14
12 DentalTown Magazine
June 2003
Point/Counterpoint: Do you take a bitewing at the crown seat appointment?
doctored
Marin County, CA
Posts: 1,867
Reg.: 9/21/2002
hudley
Saginaw, MI
Posts: 959
Reg.: 9/18/2002
Posted: 1/11/2003 7:24:00 PM
Continued from page 12
Post 11 of 115
I think taking a bitewing simply demonstrates the crown fits from one view. I rarely do it.
Here is a question. Just because the crown looks acceptable on a radiograph does that mean
the tooth was cleansed and isolated during the placement? In fact it can look good on the
radiograph and be cemented with all kinds of contamination. I see it often. A patient comes in
with a crown in hand done somewhere else. Sometimes from very upscale offices. Nice prep
and casting. The cement is discolored and smells bad. The bitewing looks great with the
crown in place. It just wasn’t cemented with good technique. The best cements will fail if
contaminated by saliva or applied to a contaminated tooth that wasn’t thoroughly
cleansed.
Posted: 1/11/2003 7:55:00 PM
Post 12 of 115
I like the record a bitewing gives me. Not really for the legal ramifications so much as I can
compare it to subsequent radiographs upon recall. I don’t find the extra time or expense
amounts to much. Of course I check the entire margin with an explorer and 4.8x magnification with headlamp. But I can never visually see those interproximals. Rod, your point about
a two-dimensional film is well taken, but I still like my record.
Doctored, you’re saying a radiograph proves nothing? So, if cement is discolored and smells
bad, it has to be poor technique? How about recurrent decay? How about patient factors?
What you’re claiming sounds pretty unsubstantiated. Your posts are quick to assume other
dentists aren’t as careful, skilled or ethical as you.
david_f
Connecticut
Posts: 2,908
Reg.: 9/12/2000
doctored
Marin County, CA
Posts: 1,867
Reg.: 9/21/2002
DrDanDDS
Longwood, FL
Posts: 1,640
Reg.: 2/17/2002
Posted: 1/11/2003 8:05:00 PM
Post 13 of 115
Hudley, the problem is the patient who moves and the subsequent dentist has the attitude
Doctored demonstrates. Now you’ve got a patient problem, which you can’t control, so it’s
nice to be able to show proof it looked good on insert.
Posted: 1/11/2003 8:26:00 PM
Post 14 of 115
I didn’t mean to be talking down my nose. I was just trying to point out that a great casting
can fail if not cemented under clean and dry conditions (not desiccated). Hudley, the cases I
am talking about do not always have recurrent caries. They simply were leaking and that
indicates to me the cement did not adhere and set properly. Some cases are difficult to isolate.
In fact it is sometimes more difficult to cement a crown without contamination than to prep
and impress IMHO. It would be nice if we had cements that were more forgiving but we
don’t as of yet. Taking a radiograph is not a bad thing. I sometimes do it if I have doubts
about a deep margin. If it looks good I place a cord and do the best I can. I doubt anyone
here at DentalTown is saying cleansing and isolation during crown cementation are not
important factors to successful crown treatment. I used to work as an associate and my boss
cemented crowns without any regard for surface preparation. Maybe that’s why I think it’s
important. I used to re-cement his work regularly, and yes, they did smell bad.
Posted: 1/11/2003 9:01:00 PM
Post 15 of 115
Hudley, FWIW, I thoroughly cleanse/disinfect all preps, place HurriSeal, then cement with
Rely X and Vitremere. We also take pre-cementation BWs on posteriors and PAs on
anteriors. I want to know for my own satisfaction that all looks fine on the film. I hate it
when I find an open margin on routine recall a year later when the hygienist takes BWs. If
there’s a problem, I want to know about it NOW...not a year later.
Continued on page 40
14 DentalTown Magazine
June 2003
Point/Counterpoint: Do you take a bitewing at the crown seat appointment?
drbarotz
Denver, CO
Posts: 294
Reg.: 9/17/2002
Rod
Mission Viejo, CA
Posts: 4,000
Reg.: 3/17/2000
stevebelldds
Westchester, NY
Posts: 293
Reg.: 1/12/2002
KDaleDDS
Floyds Knobs, IN
Posts: 121
Reg.: 9/14/2001
Posted: 1/11/2003 9:49:00 PM
Continued from page 14
Post 17 of 115
Cut good preps with margins that an idiot can read and the need for a BW is moot. I
occasionally do have to cut a crown off but it happens once or twice a year...hardly enough to
justify taking a BW on every crown I seat. I do not fault those who do, just personally do not
think it practical.
Posted: 1/11/2003 10:26:00 PM
Post 18 of 115
Now another question. For those of you who routinely take films, do you prefer ‘pre’cementation, or ‘post’-cementation films? If you get a ‘pre’-cementation film, you have the
opportunity to try and find the problem, and ‘fix’ it. But on the other hand, you don’t have a
record of the ‘finished’ case and confirmation that no large ‘chunks’ of cement are lodged
interproximally. So, does it boil down to wanting to be sure before you cement, or wanting a
‘record’? Just curious regarding the motivation.
Posted: 1/11/2003 10:34:00 PM
Post 19 of 115
I consider a pre-cementation BW to be my standard of care. I want to know right then and
there that the margins look good. Why wait and find out at recall you don’t like the fit?
Posted: 1/12/2003 6:49:00 AM
Post 21 of 115
I have found the explorer alone to be a very predictable and highly accurate way to find my
open margins. Visual and tactile examination is far superior to radiographic examination. If
the crown passes visual and tactile confirmation tests, then it is very predictably an excellent
fitting crown. Sure surprises happen, but they are very rare and not any more frequent than
the surprises that happen in direct restorative dentistry. If I took a radiograph of every crown,
then under the same philosophy, it seems to me it would be necessary to take a postrestoration radiograph of my direct restorations.
Nothing wrong with confirming the fit with a radiograph, but it seems unnecessary to
me...and certainly this is not a standard of care (my dental school instructors didn’t need a
radiograph to tell me to do it over...their golden explorer had all the needed authority!).
A post-cementation radiograph makes more sense for legal documentation, but I don’t
routinely do this.
Dr Thom
Renton, WA
Posts: 651
Reg.: 12/11/2001
Posted: 1/12/2003 12:00:00 PM
Post 25 of 115
Gerard Chiche uses Fit Checker routinely to check marginal integrity. You will know right
away if your casting fits and Fit Checker isn’t subject to angulation problems like a film. If
you aren’t familiar with the product it is made by GC and it is a very thin impression type
material. It only takes about 30 seconds to set. I use it routinely on bridges but not that often
on single units. It’s been my experience that if I provide the lab with a good impression then
seating isn’t an issue and a BW is overkill. My keys to a good impression are using magnification (2.5 DFV loupes), keeping the bur away from the tissue, Ultradent cord, and the
ND:YAG laser to provide hemostasis and remove any tissue that prevents me from seeing the
packing cord. I use a one cord technique and leave it during the impression. The laser allows
me to trough the sulcular tissue if necessary to allow the impression material to reach the
cord and get below the margin. The cord in the sulcus also prevents me from violating the
biologic width. If the old restoration is really deep I’ll just use the laser and no cord or send
the patient off for crown lengthening. I am the first to admit that I see my “short comings”
show up on recall BW’s just like anyone else. It just doesn’t happen often enough to warrant
taking a film IMO.
Continued on page 44
40 DentalTown Magazine
June 2003
Point/Counterpoint: Do you take a bitewing at the crown seat appointment?
jefftonner
Dental Malpractice
Defense Attorney
Phoenix, AZ
Posts: 286
Reg.: 5/30/2001
Posted: 1/13/2003 4:44:00 PM
Continued from page 40
Post 48 of 115
First, there is not a DDS alive or dead who performs C+B and has not cemented a PFM with
an open margin, or less-than-ideal contacts, etc. Second, I personally do not feel the SOC
requires a pre- or post-seat BW. I would guess that maybe 10% of the dental charts I review
contain this safeguard.
A simple C+B case will not make it to the court system, but they do constitute a typical board
complaint. The board often will send the pt to an independent evaluator. What if s/he finds an
open margin? If the defendant-dentist has a BW, then it is much easier to defend. The question then becomes how the margin opened between the seating and independent exam dates.
We have eliminated the possibility it was cemented that way. Without this film, it could have
seated this way and the natural inclination is to assume so.
As for pre- or post-seating BW, I prefer the latter. It is possible for a pre-seat BW to confirm
good margins, but the PFM was not cemented properly. A post-seat BW is better from my
standpoint because it is more definitive. From a clinical standpoint, you may feel otherwise
and I respect that.
Let me also speak briefly about practice standards. There are those that must be followed
every time. But let me offer an alternative to using a BW all the time or never. You could
chose to use them where your gut or other identifying factors tell you that this pt may be
trouble. After all, these pt are more likely to file a board complaint. Using this method, you
(1) can save valuable clinical time for those pts who would understand that an open margin
happened and that you will replace it for free, and (2) can take a BW for those pts more
likely to cause trouble.
Do you need to do this in your practice? No. The great majority do not. Will it help?
Absolutely. Should you do it? I leave that up to you.
gordonjchristensen
Posts: 12
Reg.: 4/7/2002
Posted: 2/19/2003 12:48:00 PM
Post 73 of 115
Many years ago, I did a project on the marginal fit of castings. It was done on cast gold alloy
restorations. We attempted to determine the opening of margins as evaluated by radiographs.
We found that the average marginal opening at gingival margins was not observable on a
radiograph. I concluded that making a radiograph at the time of crown seating was not
necessary unless the clinician feels there is a reasonable chance that the restoration does not
fit, in which case the opening will show on a radiograph.
If the impression was adequate, and the margins fit on visually observable portions of the
restoration, the possibility of inadequate fit elsewhere on the restoration is slight.
billstrupp
Posts: 1
Reg.: 4/26/2003
Posted: 5/7/2003 12:21:42 PM
Post 117 of 117
I rarely use radiographs to affirm fit except in the case of implants. The primary reason for
not using them is because 95% of the restorations I place are partial coverage (gold or all
porcelain) with margins that finish “outside of the biology” of the patient, i.e. supragingival,
and therefore visible to affirm fit.
Our protocol is to provide the laboratory with perfect full arch impressions made using
custom trays and then have the technicians use microscopes in every phase of fabrication of
the restorations. In reality, when this protocol is followed, checking for marginal fit becomes
a secondary or tertiary consideration.
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the Fixed Prosthodontics forum––Search Words (typed exactly): bitewing at crown seat appointment.
44 DentalTown Magazine
June 2003