Dear Dr. Reitz:
The white fillings in my front teeth have yellowed. I suspect it’s either something in my diet or more likely because I smoke. Will polishing the fillings remove some of the stain, or will I need to have them replaced? – Joyce
No one wants a cavity in a front tooth. Fortunately, a well-placed composite filling can fix the tooth and not leave a trace. Unfortunately, over time, composite filling material stains and often looks bad long before it wears out. A recently published study has determined that composite fillings in cigarette smokers stain and wear out faster than those of nonsmokers.
We all know cigarette smoking is bad for our health, but the new study has determined that cigarette smoke alters composite fillings, causing them to stain more easily. Smoking is not just bad for your lungs, but it is bad for your fillings.
To perform the study, researchers in Brazil made 10 discs of composite and divided them into two groups. This experiment was not done in the mouth but on a lab bench using simulated smoking conditions. The one group of discs was exposed to cigarette smoke daily for 21 days, then washed and stored in water. The second group of discs was kept in water as the control.
The Brazil study discovered chemical elements from the cigarette smoke, such as cadmium, arsenic and lead, penetrated into the composite resins, changing the structure of the composite. This change in the composite made it more water-soluble. Being soluble causes the surface to erode. An eroded surface will wear out more quickly during chewing and thus shorten the life expectancy of the filling.
Observing patients in our practice, it is obvious that the longevity of white composite fillings varies from person to person. In one person a white filling will last for many years, while in someone else the filling will pick up stain and appear to wear out faster. As for your question about removing the stain, it cannot be removed by polishing.
The researchers believe tar particles in the cigarette smoke penetrate into the composite material and loosen the bonds that hold the composite together, leading to faster wear. In essence, cigarette smoke infiltrated the composite resin, causing it to break down easier and reducing the life of the composite.
Smokers have at least two problems: more rapidly stained composites and shortened composite life. Wow. If smoking can do this to hard composite material, imagine what it does to a smoker’s lungs.