Filling the teeth with gold or silver, or making a tooth from both of them is permissible at the point of necessity if nothing other than them (gold and silver) will help.
In the musnad of imam Ahmad, Arfajah bin As’ad hit his nose on the day of Kilaab war. He took a silver nose and stuck it. So the Messenger of Allah (peace be upon him) ordered him to take gold nose.
It has been proven that many of the imams had plated their teeth with gold, such as Musa bin Talha, Abu Rafeh, and Ismail ibn Zayd bin Thabit, while Hasan Al Basri and the Hanafi imams approved it.
It was stated in the fatwa of Sheik Hasanai Makhlouf on November 18th 1946 that:
Filling, cover and wire made of gold or silver is permissible. We can either take from the narration of imam Ahmad’s slight permissibility or go by the doctrine of imam Mohammed ibn Al_Hasan from the Hanafi Imams or even stick to its permissibility as a result of necessity to use them, including platinum and similar metals other than gold.
Nothing prohibits us from using silver.
Islamic fatwas volume 14 page 1302, volume 10 page 1710, and ‘Ghadaul baabi lissaafarini’ vol. 3 p. 172
Islamic fatwas volume 14 page 1302, volume 10 page 1710, and ‘Ghadaul baabi lissaafarini’ vol. 3 p. 172