Hand pieces may have variable speeds for cutting as opposed to cleaning. There is no single, ideal material for dental fillings. The area is prepared and cut to the desired shape and dimensions. The filling is chosen and the prepared area is filled. Amalgam becomes solid within an hour and reaches full strength after 24 hours.
Composites require no shaping of the cavity and are put on the cavity in layers.
Gold and porcelain are fabricated outside the mouth, inserted and cemented in place.