"Came in for a dential procedure with mother"

Came in with my mother so that she could get dental treatment whilst being under conscious sedation shes wished for me to stay with her the whole time. I got told to leave onse she was under sedation. I felt awful on her as she wanted me to watch and see what they where doing to tell her when she woke. I was sat for 1 hour and 15 mins in waiting room. When my mother came around she then told me she heard the sedation nurse and other nurse rushing the dental therapist and telling them to hurry as another patient is due. She then heard the dental therapist replying to say that they cannot go any faster and cannot be rushed. Im appalled by this and this is why we should have the right to stay in with the patient.