Thanks for all the responses..

DH and I have talked about it, and discussed further with my dentist friend and have decided to go with the GA (providing that all is ok with the outcome of the heart murmur). We are booking it for October, cause there is more chance of the heart murmur having been invetigated, rather than the the date available to us in September.

I really doubt DD would cope too well in the chair, and I am sure she would pick up on my uneasiness of the needles and such at the dentist.. We are going to explain it to her about a week or so before it happens. Am hoping that is enough time for her to process it without being too long and freak her out.