Teeth whitening can rejuvenate your smile and help it look younger. Some people try to whiten their dental restorations, such as dental crowns or veneers. Have your crowns started to yellow? Consider some possible causes and why teeth whitening won’t help.

Damage During a Dental Cleaning

Power instruments: When you receive a dental cleaning, power instruments are used to blast away stains on your teeth. But these same instruments can damage dental restorations, including crowns. One example is the Prophy Jet. It uses sodium bicarbonate to clean and whiten natural teeth. But this powerful treatment removes the glaze on your dental crowns and leaves them unprotected from stains. The crowns can turn yellow but treating them with teeth whitening won’t help.

Acidulated phosphate fluoride: This fluoride treatment is applied to teeth to prevent cavities. But if the chemical is in contact with your dental crowns, it will etch away the glaze on them and cause your crowns to stain. And a tooth whitening kit won’t improve the color.

Damage When You First Received Them

If your dentist adjusts the front surface of your crowns, special care is needed to avoid damaging the glaze. It’s also possible that the laboratory that made the restoration didn’t properly glaze them. In either case, your crowns will darken over time, and bleaching gel won’t improve the color.

Material Used to Make the Crowns

Sometimes people think they are receiving porcelain or ceramic crowns, but later learn the crowns are made of dental composite. Dental composite doesn’t resist stains.

Why Won’t Teeth Whitening Help?

Whitening treatment only works on natural teeth. Bleaching gel penetrates through tooth enamel and breaks down stains in the layer beneath it, or dentin. But the gel won’t penetrate porcelain or ceramic. Dental crowns are colorfast.

If your dental crowns are discolored, visit an accredited cosmetic dentist for an examination. He or she will explain the cause of discoloration and explain your options for regaining a bright smile.

This post is Michael Szarek, DMD a Lowell, MA accredited cosmetic dentist.