When a tooth completely comes out of socket it is called AVULSION of tooth. In this scenario the golden time to reach a nearby dentist is 60 minutes.
Never clean the tooth or root with a scrubber or tooth brush
Never carry the tooth dry or in a box wrapped of paper
Preferable mode of carrying the tooth are regular milk (not hot), tender coconut water, patients saliva, HBSS, cotton, lens solution, in patients own mouth saliva, placing it back in the tooth socket etc.
If these above instructions are followed then success rate for re-implanting the dislodged tooth is very high.