Factors affecting irrigant extrusion during root canal irrigation: a systematic review.

By Boutsioukis C, Psimma Z, van der Sluis LW

Date: 01/2013
Journal: JOE


  • Systematic review and critical analysis of published data on irrigant extrusion to identify factors causing, affecting or predisposing to irrigant extrusion during root canal irrigation of human mature permanent teeth.


  • N= 40 case reports (from 1974-2012) and 10 ex vivo studies (from 1999-2011)
  • Exclusion criteria: Use of obsolete/toxic materials, immature permanent teeth, Studies reporting direct injection of irrigant into soft tissues (e.g. in place of anaesthetic) rather than extrusion during root canal irrigation, Studies reporting subcutaneous emphysema or similar conditions (e.g. pneumomediastinum) related to root canal irrigants or studies reporting drying of root canals using pressurized air. Animal studies excluded.
  • Inclusion criteria: Studies concerning irrigant extrusion; clinical studies, case reports or ex vivo studies. Mature permanent teeth.  Any language.
  • Positive/negative control: N/A
  • Control & Design: Six databases searched –  Cochrane Library, LILACS, PubMed, SciELO, Scopus and Web of Knowledge. Hand searching also conducted in all issues of six Endodontic journals. Keywords: ‘irrigant’, ‘rinse’, ‘extrusion’, ‘injection’, ‘complication’, ‘accident’, ‘iatrogenic’, ‘root canal’, ‘tooth’ and ‘endodontic’.


  • Lack of clinical studies (unethical) focusing on irrigant extrusion during irrigation
  • Ex vivo studies were inconclusive due to major methodological limitations and extensive variability in the protocols employed.
  • Case Reports:
    • Size of root canal ranged from 20-70
    • 8/46 accidents showed overinstrumentation of apex
    • 42/46 accidents used NaOCl as sole irrigant
    • Open-ended needle used in 3/46, Closed-ended in 1/46
    • Initiation of signs/symptoms immediately in 34/46 accidents
    • “High flow rate” caused 10/46 accidents
    • Wedging caused 5/46 accidents
    • Both vital/non-vital pulps w/or w/o PA lesions were involved in accidents (Kleier et al. 2008), however, accidents may be more probable in teeth w/non-vital pulps and PA lesions.
    • Extrusion accidents more frequently reported in women (85%) and in maxillary teeth (85%) (Kleier et al 2008)

Clinical Significance:

Care must be taken when irrigating w/NaOClto minimize extrusion. Possible considerations: decrease flow rate, no wedging, women, maxillary teeth.  More evidence needs to be conducted/standardized in order to prove cause-effect.