The Difference Between a White and Silver Filling.

Composite: The dentist only removes the decay.  Essentially a 'hole' surrounded by healthy tooth remains.  That 'hole' is then filled with white composite that is bonded or glued to the sides of the 'hole.' This strengthens the tooth, looks like the tooth and feels smooth.

Amalgam or silver fillings: Since no bonding or 'glue' is used with a sliver filling, the dentist has to remove the decay and then shape the tooth in such a way that the silver filling will lock itself into place.  This means that healthy tooth has to be removed to prepare the tooth for a silver filling.

We like to keep as much of the natural, healthy tooth as we can.  Therefore a composite is likely recommended.

Image: The black lines indicate the amount of tooth removed to prepare the tooth for a filling.  The gray indicates the cavity or decay.