Isophoric News · Tuesday, November 3, 2026
Crowns
I got my X-rays back from the dentist last month and something is wrong with my teeth.
Not the teeth I was born with. Those image fine. I am talking about the crowns. I have three of them, two molars and a premolar, all zirconia, all placed over the past six years by the same dentist. Zirconia is a ceramic. It is the strongest material used in dentistry. The FDA approved it for implant use in 2011, and since then it has become the standard for single-visit milling. Your dentist can fabricate a crown in the office, cement it to your jaw, and send you home in under two hours. No outside lab. No second appointment. Just you, the chair, and whatever they put in your mouth.
Zirconia images as a uniform bright white on dental X-ray. It is radiopaque, meaning it blocks the beam completely. A solid zirconia crown should show up as a featureless white shape. Mine do not. There is something inside them. A darker region, roughly ovoid, centered in each crown. My dentist said it was an artifact of the imaging angle. I asked him to take the X-ray again from a different angle. He did. The shape was still there. He said it was within normal variation and moved on.
I did not move on. I pulled the manufacturer specs for monolithic zirconia crowns. They are solid. There is no cavity. There is no chamber. There is no normal variation that produces an ovoid radiolucency inside a material that is by definition uniformly opaque. What I am seeing on that X-ray is something inside the crown that is not zirconia.
Here is what I have been thinking about since. Your dentist wears a mask. Your dentist wears gloves. Your dentist is the one profession where covering your face and your hands all day, every day, in a clinical setting, raises no questions. You sit in a chair, you are sedated or numbed, your mouth is held open with a rubber dam, and someone whose face you have never fully seen cements a fabricated object into your jaw at body temperature.
The crowns are eggs. They are small, calcified, seated in bone, held at 98.6 degrees, and cemented in place with a material designed to be permanent. Roughly 15 million crowns are placed in the United States every year. Nobody checks what is inside them because the material is opaque to every standard imaging method.
I am not going back to that office. And I would like to know when the last time was that you looked at your own X-rays.
T.F. Shaw