If you see yellow patches on your teeth, your first thought might be that it's time to think about whitening your smile. Interestingly, it's not necessarily your teeth that need attention. Most contemporary fillings are made of a sophisticated composite dental resin, which your dentist specially mixed in order to match the color of your teeth. It can be such a good match that you may forget the precise location of your fillings. The yellow patches you're seeing can be discolored dental resin, and not in fact stains on your actual teeth. How can you reverse this discoloration?

Whitening Won't Work 

Don't attempt to use an at-home teeth whitening kit. Composite resin has a different porosity from dental enamel (the substance that forms the outer layers of your teeth), and any response to your whitening efforts will be negligible. If anything, your dental enamel will whiten, but the composite resin will not—making those discolored patches stand out even more.

Enamel Pores

The surface makeup of enamel is vastly different from composite resin. Enamel has microscopic pores that trap color pigments from the foods and drinks you consume. This changes the color of the enamel; it can be reversed by using a whitening agent that enters the pores and bleaches away these trapped pigments. Composite resin has some porosity, but stains in a different way (and at a different rate) than dental enamel. As such, you'll need some help from your own general dentist. 

Assessing Fillings

Your dentist will carefully inspect your composite resin fillings. These fillings may still be perfectly intact, even though their discoloration is a typical sign of aging—that they've been in place for many years. It's important for a dentist to make sure that the cavity is still effectively sealed by the filling. Even microscopic openings around the filling can permit leakage, carrying bacteria into the tooth—which can cause further decay and even an infection of the tooth's nerve. If there's any doubt about the integrity of your composite resin fillings, a dentist will just replace them.

Functional Fillings

When the fillings seem to be in good working order, it may simply be that the nature of your diet has led to accelerated discoloration of the composite resin used to fill your cavities. Instead of replacing a perfectly functional filling, a dentist can perform touchup work. This involves gently filing away the discolored surface of the filling to reveal the original shade of the dental restoration. 

Discolored composite resin fillings are typically nothing more than a mild cosmetic problem, but it's the sort of problem you can't fix at home, so you'll need to make an appointment with your dentist for assistance.

Contact a local general dentist to learn more.