Dr. Hall-
My dentist’s treatment plan calls for two lower 3-crown bridges for the second back tooth forward on each side. The dentist advises porcelain fused to metal crown/bridges—due to it being a stronger material to resist grinding pressures—and wants 20% additional $$ above the PPO contract rate for the “upgraded” crown materials vs. all porcelain crown/bridges.

I have three questions:
1. Which type of crown is better and will have best chance against cracking?
2. The 20% “upcharge” labeled as “lab fees” is not a covered code by my insurance. Can a dentist charge above the PPO contract rate and refuse to use the “standard ” porcelain/ceramic crown which is covered by insurance? It seems to me that it is a “work-around” the contract rate, effectively avoiding the limited contract rate fee.
Though I may prefer to have the PFM bridges if they are indeed stronger. I simply may not be able to afford this mandated “upgrade” and I do not think I should have to switch dentists as a result of this, since he is an “in-network provider.”
3. I have all porcelain upper bridges on each side, so my other concern is will the lower PFM crowns grinding against the “all porcelain” upper crowns cause the upper to more likely crack sooner, as I will have stronger material grinding against softer material as opposed to a like material against a like material? Does that make sense?
Thank you.

-Tom from Ohio

Tom,
If you are communicating this accurately to me, then there is indeed some funny business going on with your dentist trying to get away with charging above the contract rate for your bridges. It certainly sounds to me like he or she is playing games with terminology and fees. Let’s address that first.

To sort this out, we need to clarify the terminology here.

First, for the benefit of readers who may not know, a PPO is a preferred provider organization, which is a network of dentist providers that have made an agreement with an insurance company to offer discounted fees to the subscribers of the plan being offered by the insurance company.

Then, as far as the types of crowns, my guess is that your dentist, for the crowns that are a part of the bridges, is using the procedure code D6740 – retainer crown porcelain/ceramic. Notice the term “ceramic” in this procedure code. That’s important. Porcelain isn’t strong enough to serve as a bridge even on the front teeth, much less on the back teeth. It will crack under chewing pressure. But there are other ceramics that are plenty strong enough, and many dentists are now offering these metal-free bridges. I can’t help but assume that we’re talking about one of these higher-strength ceramics here and not porcelain.

But now you’re saying that your dentist wants to “upgrade” to a porcelain fused to metal crown. A couple of problems with these games he or she seems to be playing with the terminology. First, to me the upgrade would be the other way around. The higher strength all ceramic crowns would generally be more expensive. Second, there are procedure codes for porcelain fused to metal crowns and I’m sure the insurance company would have that on their fee schedule. There are three codes for porcelain fused to metal crowns: D6750, D6751 and D6752 for porcelain fused to high noble, base metal, or noble metal respectively. Now it’s possible that the PPO will not pay for the bridge if the metal is high noble. But the noble metal is actually stronger and unless they are really cheap, they should have a fee for that.

And the idea that this “upgrade” is mandatory—that seems to me to be a violation of his contract with the insurance company. The dentist can offer you an upgrade as an option, but he or she has to give you the choice of doing the service that is covered by your plan.

About your other two questions:
The porcelain fused to metal is a little stronger, but the high-strength ceramic is plenty strong enough for a bridge on back teeth.

As far as compatibility with the upper bridges, yes, you are better off having similar materials chewing against each other. Neither one is going to “crack,” but they will wear. You would be best off contacting the dentist who did the upper bridges and finding out exactly what was used on the chewing surface and matching that. You have these high-strength ceramics, but they are often made of a framework veneered with a porcelain.

Then I have a final question for you. Let’s say you tell your dentist no, you want the porcelain/ceramic crowns because you understand that is your right under your insurance plan. Will he or she give you then the high-strength zirconia ceramic? Or will you get the porcelain which won’t hold up? Bottom line—do you trust this dentist?

– Dr. Hall

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