Just over four years ago, my 15-year-old son got porcelain crowns on three of his front teeth. Over the past two years, however, we have noticed that these teeth have gotten significantly darker and are no longer whiter than the teeth on either side. (They were when the crowns were first applied.)
Do you know why this might have happened? What should we do?
-Joyce in Boston
Porcelain crowns, if properly applied and cared for, should not change color. Is it possible that your son had a dental cleaning by a hygienist not experienced in caring for porcelain crowns?
Many dental practices use a device called a Prophy Jet to clean patients’ teeth. The mixture of water and sodium bicarbonate, combined with the force of the spray, can damage the glaze coating the porcelain crowns. Once the glaze is removed or damaged, the porcelain is very vulnerable to staining.
Another common source of damaged porcelain crowns are fluoride treatments with acidulated fluoride. This fluoride can etch the glaze over the porcelain and also leave it vulnerable to staining. Anyone who has had porcelain dental work (crowns or veneers) should be sure to have fluoride treatments with neutral fluoride only.
If you have porcelain crowns or veneers, it’s very important to get regular cleanings from dentists who are experienced with cosmetic dentistry and now how to properly care for and maintain this kind of work. Many general dentists and hygienists do not know that many common treatments can damage porcelain dental work.
As for what to do now: It is possible for a good cosmetic dentist to carefully polish them and improve their appearance. However, if the staining is severe, it can’t truly be reversed without removing the existing crowns and applying new ones.