Subtitles section Play video Print subtitles DR. JIMMY KILIMITZOGLOU: The problem with fillings is that when they’re really wide, we need a good material that’s going to last a very long time. We can’t really get away with doing composite, so porcelain is the material of choice. And the reason is when we have something hot, things expand. When we have something cold, things contract. And that can actually cause little fractures or spaces between the filling material and the tooth. And inlays or onlays are basically porcelain custom fillings that fit into the tooth. And they restore the function, they look great, and they last a very long time.