Dental bonding, or composite resin bonding, is a great way to repair teeth that have been damaged by decay, acid reflux or accidents. It is also a cheaper alternative to veneers and can last up to 10 years if well taken care of. However, one of the drawbacks of dental bonding; especially the older kind, is that it tends to become discolored over time.
The Three Types of Stain Affecting Composite Bonding
There are three types of stain that affect bonded teeth. The first and most common is surfacing staining. While bonding doesn't stain easily, it will eventually succumb to staining as it ages. The easiest type of staining to treat is surfacing staining, which is what happens when your bonded teeth are exposed to food and drink containing dark color pigments, such as red wine, coffee, and pasta sauce.
The second type of staining happens when the bonding resin absorbs the stains on the surface. The composite bonding used many years ago was notorious for this type of staining.
The last and most damaging type of staining occurs with some of the older composite resins. These older formulas contain tertiary amines (derivatives of ammonia), which cause bonding to discolor over time and turn an unattractive yellowish-brown color.
If your bonding has become discolored, you might have considered turning to whitening to save it, but, unfortunately, whitening has little effect on bonding.
Why Whitening Doesn't Work on Bonding
Whitening is an effective treatment for stained natural teeth since natural teeth are porous, and are therefore able to absorb the cleaning agent (peroxide) that removes stains. However, bonded teeth and veneers are nonporous, which means whitening has little effect on them.
Polish for Minor Discoloration
If the staining on your bonding is minor, i.e., only on the surface, your dentist should be able to polish the bonding. This will remove the stained outer layer so that your bonded teeth return to their former whiteness.
Resurface and Repair the Bonding
If the stains have penetrated deeper into the composite bonding, your dentist can remove the stained material from the surface, and then resurface the bonding to make it look as good as new.
Remove and Replace Bonding
When stains have penetrated too deeply or when the staining is due to tertiary amines (contained in older bonding), your dentist will need to completely remove the bonding and replace it with either a newer, more stain-resistant bonding, or veneers.
Replace the Bonding with Porcelain Veneers
You could opt to replace bonding with veneers. Whilst more expensive, veneers can last up to 15 years, and if placed on your anterior teeth (incisors and canines), they can widen as well as whiten your smile.
Speak to your dentist about your options. If your dentist is unable to evaluate which treatment is best for you, they may refer you to a cosmetic dentist instead who can comfortably carry out any of the aforementioned treatments.