There are certain fillers that work to stimulate collagen very well. One is Radiesse which not only stimulates new collagen production over time, but has bulk to allow immediate results that are seen just as with Restylane and Juvederm. Sculptra is different from Radiesse in that it's entire purpose is to stimulate collagen but does not produce immediate result,- i.e there is no bulk associated with it. It tends to be a better product for volumizing and facial contouring.
The filler that will most likely be used for your smile line is a hyaluronic acid base filler which has much less potential to stimulate collagen than the previous mentioned. however, they may to some extent since sometimes there is slightly less product needed over time if you continually get injected. A possibility is that the act of the injection alone stimulates some collagen production.
Hope this helps!