Yes it would I'm sure be less exposure to mercury to have them cut into pieces that are removed, rather than drilled (which gives off far more particles of mercury). That plus of course full protection and alternative source of oxygen. I think it's eye goggles, rubber dam, oxygen and sometimes even the entire face maybe covered. Mercury unfortunately is easily absorbed via the skin. i can attest to that.

Regarding mercury vapor or dust....I'm not sure. I'd suspect both are bad. Have you heard of metal dust fever? As long as you're absorbing and breathing in mercury, it's bad.

I've come away after a visit to a dental office with severe rashes and itching. It is VILE stuff. It gets in anywhere and seems to get on the hair, skin, clothes, shoes, as well as the office environment and equipment. It took me months to recover from a visit. The same thing happened the next visit and I had to stop seeing him. This was for health consultations. And he was a biologic dentist with a new office and proper extraction system to clear mercury vapor. Amazing eh? Most people probably do not get anything like this and I never used to either. It was only when my immunity was lowered by other problems later on that I began to notice this problem occuring. I have since heard a few other people have the same problem!

This is why I finally got cerec porcelain put in my teeth so I will hopefully not have to go back to a dentist. They last a long time. I cannot even go for regular cleans because of what the environment of the dental office does to me.

I think a study was done on the mercury levels of the homes of dentists and they said they were MUCH higher than the homes of people in other occupations (non mercury related). Simply because mercury gets on the person and their clothing. So picture that day after day and how the levels build up.

I have also gotten a similar problem from visiting the home of a smoker regularly. Depends on the cigarettes? Perhaps. The environment size? Perhaps yes and that it's winter, probably not aired as well. So it's not so much the direct smoke, but the toxic aftermarth build up that is an even bigger problem. Again, can take months to recover if I get enough of an exposure.
Certainly not something I expected or recognised at the time, until symptoms began to intensify and I recognised they were identical to mercury and couldn't figure out why. I finally did a bit of "google research" and discovered that cigarettes contain mercury and it is released into the atmosphere upon burning! Thus adding to the overall body burden of mercury.

So yes, mercury vapor is terrible stuff.