Who can I speak to about sedation options for dental filling?

Hi,

I need a dental filling and due to a range of reasons it might be best to do it with some form of sedation but I need to know more to make the decision. The dentist was pretty unpleasant and I'd prefer not to have her look at my teeth again or explain the sedation to me.

Is it possible to have another dentist explain it to me? Can I ask someone from my local hospital to explain it before I get referred?