There is a section in AADSAS for dental experiences where Dental Assisting hours and shadowing hours will both be entered. There is a specific distinction you will be required to make about the experience. You can choose if it was a job shadowing position or a paid position. With that being said, I think the schools want you to keep those separate. My suggestion would be to get the minimum hours of shadowing required by your schools done and then continue to assist and make sure to list all the assisting hours you have done. You'll want to meet the shadowing requirement because they asked you to, but If you have lots of assisting hours, they will see that on there as well and it will be a big boost to your application. They will essentially look at your experiences section and make a note of the total hours you have spent in the dental field, even though you still need to list the shadowing and assisting separately. I hope that made sense.