90 combined gold-amalgam specimens of three dental gold alloys and two amalgams were placed subcutaneously, intraperitoneally and in the cheek pouches of 15 golden hamsters. The appearance of the amalgam surfaces after one week was evaluated using scanning electron microscopy and light microscopy. The results showed that among the implants there was an obvious difference between the conventional amalgam and the non-y2amalgam specimens as regards accumulation of plaque, which was much more pronounced on the conventional amalgams. The cheek pouch specimens with conventional amalgams differed markedly from the corresponding implant specimens, showing very little plaque accumulation. Some possible explanations for these observations arc discussed.