Why are fillings always so big?

I've had quite a few fillings done recently, and even though they've been for relatively small cavities, the fillings themselves always seem really big in comparison to the area of decay on the tooth. Like when I looked in the mirror I could only see a small area of decay on the tooth, but then when I got the filling it was really big and covered about a half of the tooth surface. Why is that??

Why are fillings always so big?
Because the area of decay will be surrounded by weakened enamel, which will be more susceptible to decay so it is removed as well
Reply:They only feel like that, it's psychological!
Reply:remember the cavity always is bigger than it looks like.
Reply:Well it depends on the interior size of the decay, or if the matter around the visible area is infected/weakened!


U can get white fillings u know!
Reply:because there is more decay underneath the bit you can see, i hate fillings.