I have a question about unnecessary filling

Here is the background:

Before I moved to this state, I was going to a dentist in Texas for 8
years. He either redid a couple of fillings that were done either 5-6
years 8-9 years prior to that or one could be a new one, a small one
on the side or surface. I don't remember the detail one those but I
had one big filling done in early 1993 that I didn't let that dentist
in Texas touch when he wanted to do root canal. My view was that if
the previous dentist opted to do a filling on that, why couldn't this
dentist esepcially since I had been taking care of my teeth.

Since I have heard horror story about root canal, I was not keen on
root canal but he kept saying that that's the only option left for
that tooth. So, before I moved to this state, I decided to take care
of it and agreed to do root canal. So on the day of the appointment
for that, when I was asked questionnaire about my concern, I honestly
answered about the horror story I have heard and the program I saw on
20/20. Guess what? The person taking my answer immediately went to
the dentist and the next thing I knew, the dentist suggested to back
out for it. That told me that I was right to suspect that I didn't
need root canal on that tooth.

In this state, I found a top notch dentist for my sister who needed
some treatment urgently due to a childhood accident injuring the front
bottom 4 teeth. After taking care of my sister's issues, it had been 6
months since I had my clean done and so I decided to do my clean with
him. He told me about the overlay procedure on that tooth I was
concern about since the filling (silver amalgam) has been there for 11
years and I did that. But I found out that this dentist like to do
things that most dentist would not do such as filling the natural
pockets. When he told me that I had this cavity and that cavity and
needed to fill those, listing a bunch, I was like "How come my
previous dentist didn't tell me that?" That's when he said, "Some
dentist do not consider that cavity, and went on to explaining how he
filles pockets. Immediately I said, I have more important things that
I need to spend money on. Also, since I take care of my teeth and I
will be doing regular check up, I didn't see a point in filling
natural pockets. At the time, I wasn't even aware that he would have
to take out some tooth material to do such filling. He did fill some
(small ones on the side and edges) , showing me pictures and
explaining to me. He convinced me that those would become big decay
if left not filled. I let him fill those. (BTW, it was during that
visit, I realized that why my sister had so many filling needed; I was
assuming that she was just so neglectful of her teeth and needed those
filling. She sure was very negligent, worse than kids, I am tired of
babysitting my sister and so this dentist would probably redo those
filling on her every so many years.)

Then during my third time of cleaning at his office, during the exam,
he said "Oh, this one needs to be filled immediately" , saying that he
suspected some cavity. He didn't even show me the picture. I knew he
was pulling the stunt to fill one of those pockets. I didn't stop him
but the entire time there, I gave no approval of what he did. I was
hoping that he would stop bugging me about that but the next time as
well as the time after that, he brought up about it. So I stopped
going to him.

Now that I think about how he took out the tooth material to do
filling, I feel angry and regret that I did not object it to it. I
could have said that I'd go take second opinion but that would kind of
rude because he's one of the tops in his field. (I do have x-ray
before the filling. If I probe into it, I am sure that X-ray did not
show any cavity on that tooth.)

I would like to know ho much tooth material was taken out to do such a
filling? Can any dentist here give me an answer on that?

Now, I would need re-do of filling on that tooth every so many years I
guess. This is a violation done to me.