The times of using will effect on the probability mechanical isolation and not participate in any cutting.

The research shows that Max file can transport the sodium hypochlorite to the working length,

which is beneficial to effectively remove the dentine debris and smear layer of the root canal

wall in 1/3 area of the root tip, that improves the cleaning efficiency in narrow area of the root but will not change the shape of root canal preparation to achieve the best cleaning effect.