SYNOPSIS
The embryotoxicity risk of indium-containing dental alloys was examined. Ag-20% In and Ag-Pd-Au-Cu In (6% In) alloys were experimentally prepared, and their embryotoxicity risk was examined by the Embryo Stem Cell Test (EST) protocol. Abutment teeth were prepared for the left and right molar regions in an upper and lower jaw model to produce full crowns using both alloys. After mounting the full crowns on the model, the model was attached to an articulator that was improved to simulate jaw movements through motor and cam mechanisms, and mechanical abrasion movements were continued for 6 and 12 hours. The myocardial differentiation rate of ES-D3 cells was slightly lower for Ag-20% In alloy than for Ag-Pd-Au-Cu alloy. No difference was noted in cell viability between ES-D3 and Balb/c-3T3 cells and the sample-free control group.
The embryotoxicity of Ag-20% In alloy was tested by whole rat embryo culture, demonstrating that the embryos were normal without any significant difference in yolk sac diameters, anterior-posterior lengths, head lengths, numbers of somites, or amounts of protein compared with the control group.
Thus, the embryotoxicity risk of the experimental indium-containing alloys was negligible.

Key words: Ag-In alloys, EST, whole embryo culture, ES cells, Bulb c/3T3 cells