On the basis of the literature, it can be concluded that there are no absolute rules regarding the placement of bases under amalgam restorations. The following recommendations are offered: A base should not be used unless its use is indicated clearly. When a base is indicated, it should be used with the minimum thickness necessary to achieve the desired result. Lost dentin should not be replaced with a base in an attempt to simulate an ideal preparation. A stronger base should not be placed over a weaker base, for strength. The entire base is only as strong as the weakest component. Covering the entire pulpal floor with a base should be avoided. Sound dentin surrounding the base should be left so that the amalgam restoration is supported by dentin as much as possible.