Thanks for the responses. I suppose I'm naturally suspicious and it's
because I've learned in life over the years that most people and
businesses will try to screw you over for more profit.   That is why I
asked because I wanted to be sure.   He was poking some of my molars
(in particular, in the left side) with the explorer to the point that
it was causing pain, and my first thought is that something like that
could've been handled more gently.   I was just concerned about
whether or not he was intentionally damaging my teeth, so as to
justify charging me more for work I didn't need before I arrived.

After he was done doing all of his poking around, he told me that I
had several cavities that needed fillings. Now just by looking very
carefully, I don't have any visible cavities and I don't feel any real
"pain" on any of the teeth while eating, so I'm not sure what he was
on about.   The truth is that I came in with the express purpose of
having one tooth filled that had been chipped a while back while
chowing down on a steak, but he had me undergo an exam where he
checked out all my teeth much to my chagrin.

I was very disappointed with the service of this place.  They took all
these x-rays and examined my teeth, and quoted me a price of $2,000+
to fix all of the teeth.   I don't have medical insurance and I only
pay in cash, so I let them know that I came with the express purpose
of having that one tooth filled, as I had mentioned to their people
before and after having the x-ray and exam done.

The dentist said he would take a conversative approach and that the
tooth in question could be filled with material, but may require a
direct PU (whatever that is), and so the quoted price was $227 for the
filling and etc on that one tooth.  Just like I wanted.   I was told
to come back in 3 hours for the work.    He said that a "root canal"
might be possible, depending on whether or not any of the nerve is
exposed while clearing out the decay, but likely would not involve
that.

I went back to the place and the people at the dentistry office then
told me to be prepared to pony up $600+ (in addition to the $227) just
in case if a root canal is needed, as it could be a possibility.

What I don't understand is, shouldn't they have a pretty good idea if
that is really needed or not when they take all the x-rays and
exams?    If not, then what's the point of doing all of that?

I told them that since the dentist had said that there's a chance it's
not possibly needed, why not just do the filling?   It's my
tooth...just fill it like I said and do your own....don't need and
can't afford a root canal.    And why don't they remove the decay and
see for sure whether or not if a root canal is actually required, and
I will pay them for the work up to that point?

To this, that was refused saying that once the dentist starts, he
can't stop and that I better have another $600 handy.

Like I said, I pay cash, don't have health insurance, and the idea of
paying $800+ for a damn tooth filling is ridiculous!  The tooth isn't
in pain, so it's not down to the nerve.

I felt that this dentist wasted my time and money to give me an exam
and basically tell me what I already knew: I need a filling.    I
regret going to this dentist and I lost money I could've made at work
that day.