In a couple of weeks I have to have root canal treatment for a crown
(pre?molar).  I have several other fillings and they are all white as
I want to avoid amagum. My (new) dentsist just happened to mention
that the treatment I am shortly to have involves amalgum and I said I
wanted to avoid that material. He said "ok but it's stronger". It's
only now it occurs to me that perhaps he meant I have no choice ir
*has* to be amalgum for this work. I'll call him and ask next week but
would appreciate knowing if I do have a choice of materials used.
So...

-Can I have the root canal treatment and crown which does *not*
involved amalgum at any stage?

-Is the amagum used for the (excuse my lack of knowledge about this)
shaft or stem that is inserted in the tooth?

-Why is that shaft/stem there: I thought the crown was fixed by
adhesive?
Thanks.