Hello Dottie,Porcelain overlays, or onlays, are used to restore decayed or damaged surfaces of back teeth. They are stronger than a dental filling and are a more conservative approach than a dental crown. Porcelain veneers are used on front teeth to change their shape, color and size. I would recommend seeing an experienced cosmetic dentist for a consultation to learn more about these procedures. The best way to determine if the dentist you select is going to give you the results that he/she claims, is by viewing before and after photos of his/her patients that have undergone similar or the same procedures. Good luck and I hope this helps. Follow me if you have more questions.Sarah Thompson, DMDSt. Louis, MO area (O'Fallon, IL)Real Self 100