S.C.
Hi S.,
I used a side rail when my boys switched to their toddler beds. I used the same sheets on the toddler bed that I used in the crib and the side rail made them feel like they were still enclosed and "safe". Once they switched they never looked back and I never had any problems with them getting out of bed until it was morning and they were allowed to get up. They always came in to my room and woke me up when they got up which worked great. The only time they called for me is when they were sick.
Hope this helps - S.