recut after contact with any drug, saliva or other moisture. Schoonover and Souder5 found stain­ ing to be the result of electrolysis, which was common to leaking fillings having rough margins and surfaces which col­ lected food debris as an electrolyte. They concluded that restorations with tight margins well-finished and polished would not corrode and stain tooth structure if given reasonable mouth hygiene. Massler and Barber7 observed that cement bases protected cut dentin against staining. Cement bases, however, are not the solution to the problem. Black8 taught that amalgam or any other dur­ able material seated on cement would not resist functional stress. Copalite var­ nish will seal cut dentin against thermal shock and against staining, without the insecurity common to cement bases. Amalgam restorations will give a serv­ ice second only to that of well executed gold foil restorations. Amalgam can be removed and replaced without too much lost effort, if gingival recession continues or if caries recurs. It can be used in regions inaccessible by the gold foil tech­ nic. It is a splendid substitute for gold foil where the temperament, time, health or finances of the patient favor this easier, quicker restoration. Under fa­ vorable circumstances, including good mouth hygiene, amalgam restorations will give many years of service. 632 Republic Building