Why do I need a 4+ surface porcelain onlay?

My dentist stated I need to have a tooth onlay.

Now I got the estimate and Description say Onlay Porc/Ceram-4+Surface. What does that mean 4+ surface? I thought I was getting one tooth onlay.

My plan covers a Max of $1000 and they are billing me 1300. Plan will only pay 923.50. Why do I need 4 +surface on the onlay?

Any insight would be greatly appreciated.
– Hector in New York

Dear Hector,
You’re running into some very technical jargon here, and I can see where it may be hard to understand.

The 4+Surface refers to the number of surfaces of the tooth that are covered. Insurance plans reimburse more for restorations that cover more surfaces of the tooth. There are five surfaces on any back teeth – the chewing surface and the four sides. So you’re just reading the documentation of the dentist that this onlay covers four or more surfaces and thus entitles you to their maximum benefit for this tooth. Onlays usually cover four or five surfaces.

And $1300 sounds like a very reasonable fee for a porcelain onlay in New York. You are experiencing first-hand how dental insurance has not kept up with the times. Back in the 60s, their common $1000 maximum benefit for a year would cover a reasonable amount of dental work.  Today they have the same yearly limit and it covers very little.

And for those who don’t know what a porcelain onlay is, it is a very nice restoration. It usually covers the entire chewing surface of the tooth, so it reinforces a weakened tooth. But it only goes partway down any of the sides of the teeth. Since it usually doesn’t touch the gum tissue, it is very comfortable, and requires less grinding away of the tooth. If you are interested in having a porcelain onlay, ask Dr. Malone.

Related links:
A related restoration is a porcelain crown
Read about how to fix crooked teeth
Lafayette cosmetic dentist