Why are my porcelain crowns turning dingy and yellow?
I got four porcelain dental crowns placed on my upper front teeth less than a year ago, and they’re already getting discolored. This is frustrating because they’re practically new and I don’t smoke or drink a lot of dark-colored beverages. Why are my crowns turning yellow so quickly? Do they need to be replaced?
— Eliza from Eugene, OR
Porcelain does not stain easily. Your natural teeth are actually more likely to pick up stains and turn yellow than porcelain because porcelain restorations are covered with a non-porous glaze. So if your new crowns already look discolored, then this is a sign that something is wrong with them. Either they were not of the quality you were led to believe at the time they were placed, or something has happened in the months since that caused damage to them.
Here are three possible reasons that your dental crowns are turning yellow:
1. You have recently whitened your teeth.
Teeth whitening treatments do not affect the color of porcelain dental crowns, but as your natural teeth lighten in color, this can make your crowns look dull and yellow in comparison. Granted, you did not mention that you have had whitening treatments, but if you have done any teeth bleaching treatments lately, then this could be a very simple explanation for the reason your crowns look discolored.
2. Your crowns have been damaged.
The protective glaze that helps porcelain crowns retain their color and gloss could have been compromised. The most likely way this could happen is if a hygienist used a power cleaning device on your teeth during a professional teeth cleaning appointment. Hygienists sometimes use a device that blasts a high-pressure stream of baking soda and water on teeth to remove stubborn stains. If your hygienist used this instrument on you, he or she was not careful to avoid your porcelain crowns. The high abrasiveness of this treatment could then have stripped the glaze from your crowns and left them susceptible to picking up stains.
Another possible way your crowns could have been damaged is if you were given an in-office fluoride treatment with acidulated fluoride. This type of fluoride can chemically damage the glaze on porcelain crowns.
Yet another possibility is that your crowns were damaged before they were even placed on your teeth. Perhaps they were not properly glazed during the fabrication process or maybe the glaze was worn down when your dentist was making adjustments.
3. Your dentist placed crowns made of a cheaper material instead of porcelain.
This may be the least likely scenario, but unfortunately, it’s not unheard of. Some patients have received what they thought were porcelain crowns only to learn later that they were made of composite instead, which is prone to staining.
At any rate, it’s clear that something is wrong because your porcelain crowns should not be turning yellow, even if you drank coffee all day, every day.
At this point, we recommend that you seek a second opinion from a cosmetic dentist you can trust. This new dentist can help you learn more about the actual composition and condition of your four so-called porcelain crowns and help you find out the cause of their discoloration.
You are very likely entitled to a refund and then some, if it turns out that your current dentist performed sub-par restorative work. Please see our post responding to a concern about a shoddy porcelain veneer to see our advice for negotiating a refund from your dentist.