The large silver fillings tend to act as a wedge in your tooth and can split them. Imagine a metal wedge in a tree and you using a hammer to hammer it in…it splits the tree. Thats why large fillings turn into cracked teeth.

I can attest to this.. particularly if the filling goes completely or almost completely across the tooth. I had a dentist when I was young that ‘overdrilled’ when doing fillings, the result being several cracked teeth now covered by crowns. I now pay a lot more attention to what doctors/dentists want to do.. and ask questions as well as try to get informed. There are good and not-so-good.. doctors and dentists.

I would also watch the type of toothpaste you use. Many of them add sugar to make it more palatable.. Best results I have had are with the Arm&Hammer baking soda based toothpastes.. some of them also contain Hydrogen Peroxide. They taste like crap but work very well. Be careful of keeping the toothpaste with Hydrogen Peroxide in your mouth too long though.