Yes, this is true. The Pittsburgh Dental School did some research and found that people who drink and/or smoke have a greater number of filling that fail.
The interesting thing is that a filling failure could also be a genetic condition in most people. A difference in the gene for matrix metalloproteinase (MMP2), an enzyme found in teeth, was linked to increased filling failure. Those that have that difference could be at higher risk for filling failure and drinking and smoking can amplify it in them quicker than a person without it who smokes and drinks.