The possibility for the clinical application of an experimental restorative material, which is composed of an Ag-Sn-Cu-Pd spherical alloy and a Ga-In-Sn-Ag alloy, was examined by observing periodic changes during class I restoration. In all of the restorations tested, the surface texture and the marginal integrity had deteriorated after a period of one year. Therefore, it was concluded that this metallic plastic filling material couldn't overcome physical and chemical stresses in the mouth, as a result, some improvement is required before this material can be substituted for the high copper amalgam.