In crown down technique:

Crown-Down Pressureless Technique: This technique was suggested by Marshall and Pappin. Early coronal flaring with Gates-Glidden drills is followed by an incremental removal of dentin from coronal to apical direction, and hence called “Crown-down technique. Straight K-files are then used in a large to small sequence with a reaming motion and no apical pressure – hence called “Pressureless” technique.