Question:
I went to a dentist who determined I should get a crown on one of my molars.
His office manager then came in to tell me the various options and their
prices. She seemed to really want to steer me away from a
Porcelain-Fused-to-Metal crown (PFM) and instead toward
Porcelain-Fused-to-Gold (PFG). I suspect it was because they can only
charge me $400 for the PFM, but they can charge $600 for the PFG, due to a
discount dental plan I have. She tried to give the impression that PFM
crowns don't last as long and can cause an erosion or discoloration of the
gums, as compared with PFG. She was kind of vague about it, citing only
annecdotal reports of these sorts of problems. But is there any validity to
what she's saying? Is there any online source where I can read an objective
comparison of PFM crowns with PFG? It would seem to me that since the
porcelain covers the metal anyway, it shouldn't make any difference
appearance-wise, whether the hidden metal is gold or one of the base metals.
And is there any reason why it would be better for the actual tooth itself
to be in contact with gold rather than some other base metal?
(Incidentally, what kind of base metal is normally used in PFM?) Aside from
having your teeth be "more valuable" due to the gold content underneath the
fused porcelain, is there any advantage to PFG over PFM? I'd just as soon
save the $200, unless there is a compelling reason to go with the gold. Any
help is appreciated...
Answer:
First of all, no dental gold (and certainly no casting dental gold) is
100% gold.
Many dentists will tell you they prefer high noble casting alloys for
their workability and long-term success. I have differed with some
others who have contributed to this newsgroup in the past regarding
non-precious alloys. I have seldom encountered problems with
non-precious alloys, which are generally variations on stainless steel.
There is no question that high noble crowns are easier to machine, but
this generally is not an issue IMO with a good lab that can make an
accurate casting.
Before 1980, the actual cost of gold in a crown wasn't really
significant, so there was little experience with non-precious alloys.
The early non-precious alloys contained nickel, which a significant
number of people are sensitive to. It also sometimes left a nice green
tarnish line at the gumline. However, after the Hunt brothers
manipulated the precious metal markets in 1980, it became necessary to
find reasonably good substitutes.
My lab prefers working with precious metals when implants are
concerned, because there is more metal-to-metal contact and they feel
the compatibility of the different prosthetic components are enhanced by
using all-precious. Otherwise, I use either with excellent success.
BTW, the $200 fee differential will be mostly eaten up by the cost of
the alloy, so I think your dentist's motives are not money, but their
own preference (to which I feel they are entitled, based on their own
experience).
Actually, this dentist was not in my plan. I went to him because he offered
a very inexpensive intitial exam/x-rays/consult/cleaning offer and I wanted
to get a second opinion from him as compared with the other dentist I had
gone to who was officially on my discount plan. This new dentist's offer
included 50% off any non-cosmetic procedure and the way it worked out was
that a PFM crown would be $400 while a PFG crown (which was considered
cosmetic) would be $600. I do like the dentist and I trust he would do a
good job of fitting the new crown to my tooth. So do I understand you
correctly that you think there's something inherently inferior about PFM
versus PFG? You would pay the extra $200 for the gold?
Not exactly. Some labs and some dentists will show a decided
preference for high noble metals. They are easier to work with, and
some believe yellow alloys (notably with Cap-tek crowns, which are
really a different kettle of fish altogether), give a warmer, more
cosmetic appearance. I don't think this last is really a consideration
with regard to molar crowns (I should say that I have one crown in my
mouth, a full-cast, all high-noble crown on a lower second molar with no
porcelain).
The preferences of the operator are not to be discounted; still, I have
no problems and have seen no significant differences in crowns holding
up, porcelain fractures etc. with non-precious alloys.
I will make one minor caveat--an observation by my brother that he
still sees a greater incidence of inflammation at the gumline with
non-precious alloys. He feels he has only seen this in female patients.
If true, there is no way to know what component of the alloy the
patient is responding to; as I said few of these alloys contain nickel
anymore. But a patient can develop a sensitivity at least theoretically
to just about anything, including some of the components of even
high-noble alloys.
Personally, I think that this last consideration (not to discount my
brother) is less important than other considerations such as proper
contacts, contour and esp. not burying the margin of the crown half a
mile under the gum.
I agree BTW with what Bill says about the fees being very low, but it
isn't clear to me whether this is the entire fee or just your copayment
in an insurance situation.
There is also another health issue I should mention, though it doesn't
involve you--but does involve dental and lab personnel. A longtime
poster to this newsgroup became a crusader for the removal of beryllium
from casting alloys. Beryllium is used to increase hardness and other
mechanical properties. It is apparently still used in some. Beryllium
is exceptionally toxic when inhaled, and this gentleman's wife developed
beryllium lung disease as a consequence of working in a dental lab and
breathing the dust. I agree with him that there is no place for this
metal in lab casting alloys, and that it poses an obvious and
demonstrable hazard to lab personnel.
