Had filling replaced today and bit down later and it was on a chunk of filling. could it be piece of old filling. i had two old silver fillings replaced with white ones today and later when i bit down it was a piece of silver filling. could that be a pi

Sounds : Sounds like most likely you are describing remnants of old filling. Certainly, if you just had white fillings placed, the piece of silver filling is not a current part of that. It is not uncommon for some remnants to remain though we all try to rinse them out.

I : I agree with the above answers but recommend a follow-up with your dentist to make sure that you unknowingly did not break another silver filling while you were under anesthesia.

We : We do our best to remove all of the old filling when we take them out, but sometimes little pieces get past our best methods. If you don't feel like there are any holes in your teeth elsewhere, then it is likely a remnant from the old fillings.

Chunk of material: Could be a piece of the old filling. Could be a different filling that has broken. Could be something entirely different. Take the piece of material and return to Dentist so he/she can make appropriate determination. This is not an emergency, so schedule an appointment when it is convenient for both you and your Dentist.