How high is the danger of leaving supportive bands and pins in place
after implant surgery?

Here's the situation I'm asking about:

My girlfriend had four teeth extracted and dental implants installed
about 15 months ago (with bone grafts), now she's ready to have the
abutments installed for a permanent bridge. During the original
surgery, a teflon band was put in place to better secure one of the
implants, with a pin to help secure the teflon band. The band and pin
caused her no problems whatsoever -- in fact, she didn't even know
about them until a follow-up visit about a year after the surgery, At
that time, the periodontist told her about them and said that they'd
have to be removed before the abutments were installed. She was uneasy
about this, as she didn't want to lose any more tissue (which the
periodontist confirmed would happen). She asked if removing the band
and pin was 100% necessary, he said that some patients opted to leave
them in. She decided not to have them removed. (He asked her to sign a
release, which she did.)

But... Now that she's ready to have the abutments installed, the
periodontist says that he's spoken with some colleagues who say that
it's not a good idea to leave the band and pin in place. However, my
girlfriend is adamantly opposed to having them removed.

So, I'm hoping someone can answer this question: How likely is it that
my girlfriend will suffer later complications if she does not allow the
periodontist to remove the band and pin?

I know that it's not possible to make a prediction in any specific
case, but I was hoping that someone here could give me an idea of what
kind of risk she'd be taking. For example, if 95% of patients who
refuse to have the band and pin removed suffer complications, I'll try
to convince my girlfriend to have them removed -- but if only 5% of
patients have problems, I won't bother to try to change her mind.

Thanks so much for your help!