This Dentist's office had it well-documented that I had a latex allergy. However, when I came in for a relatively minor procedure, they used latex gloves in my mouth, and consequently, I ended up in the emergency room. (And my own patient, a little girl on a ventilator, went without a nurse that night)
I understand that mistakes will happen. I am in the medical field, myself. However, when I came back to ask for my dental records -- so that I could continue care under another dentist -- they provided me ONLY documentation for that mishap... and it was highly questionable!