What is the ruling on filling teeth with a material that contains a mixture of gold, silver, and other substances, given that the proportion of gold in it is small?

The basic ruling is that gold is forbidden for men, except in cases of necessity, such as a gold nose or what is used to bind teeth. It is not permissible to fill teeth or bind them with gold unless there is extreme necessity. If other materials can be used as alternatives to gold, then it is not permissible to use gold. If gold is mixed with other materials and its effect is not apparent, then its use is permissible, though it is better to avoid it.