Histologic study of biocompatibility of the "Cristaloy 7-N" alloy.

The most commonly used alloy in dentistry practice in metal-ceramic prosthetic constructions is cobalt-chromium-molybdenum alloy. In Bulgaria the company "Sandental" created a nickel-based alloy for metal-ceramic prostheses. The aim of the study was to asses the medicobiological properties of the nickel-chromium-molybdenum alloy "Cristaloy 7-N". The study was performed on eight guinea pigs and four white rats. On both sides of the vertebral column, parallel to it, experimental plates of "Cristaloy 7-N" were implanted on one of the sides and on the contralateral side - golden alloy - .916 gold. After a different period of time - 10, 30, and 90 days, the experimental animals were eutanized and the tissues adjacent to the implanted experimental plates were studied. During the whole period of the study a skin or local or general reaction was not observed. There was no difference in succinate-dehydrogenase activity that is a sign for preserved vital activity. The electron microscopic study of the cells in contact to the implant showed normal ultrastructure of the organelles. The results obtained from the histological, histochemical and electron microscopic study gave evidence for characterizing the alloy "Cristaloy 7-N" as one having high biocompatibility.