Replacement of low copper amalgams by a group of general dental practitioners

The replacement of low copper amalgams was studied in a number of general practices in Adelaide in 1975 duplicating, by design, the method of a similar Canadian study. The results of this study are in surprising agreement with the Canadian data, and are still relevant to modern practice as the high copper alloys have not proven to have greatly superior longevity. This study involved 60 dentists who, over 271 working days, replaced an average of 6.7 amalgam surfaces/dentist/day. This is equivalent to 1541 amalgam surfaces replaced/dentist/year. In addition, the reasons given for the removal of existing amalgam restorations were closely congruent with those given by the Canadian dentists. This study also indicated that many of these restorations increased in size. This is evident through restorations extending from two surfaces to involve three surfaces.