Clinical update on root canal disinfection.

Endodontic disease is mediated by bacteria. Treatment goals should be directed to reducing the critical concentration of microbial irritants to the lowest level possible. Thorough canal instrumentation, with either stainless steel hand files or Ni-Ti rotary files, removes the bulk of tissue and microbial contamination, but adjunctive chemical agents are needed to optimize debridement. Current concepts support the following approaches: lubricating and chelating agents during cleaning and shaping; copious irrigation during all phases of instrumentation with 2.5% sodium hypochlorite, constantly refreshed; deep penetration of a side port, narrow gauge irrigating needle, constantly moving in and out of the canal space during each irrigation; removal of residual smear layer at completion of instrumentation prior to obturation.