Endodontic Irrigants in Dentistry

Essential Endodontic Irrigants

• Saline (NaCl):
  • Preferred for its mechanical properties and biocompatibility with surrounding tissues
  • Isotonic solution (0.9% NaCl)
  • Antimicrobial effect is controversial
• Sodium Hypocloride (NaOCl):
  • Most widely used root canal irrigant
  • Tissue-dissolving capability is superior to all other irrigants
  • Dissolves vital and necrotic pulp tissue and organic components of dentine and smear layer
  • Displays strong antimicrobial activity with short contact times
  • Neutralizes or inactivates lipopolysaccharides
  • Has good solvent effect against organic structures, is antimicrobial, and easily available
  • Effectiveness is dependent on concentration and duration of exposure
  • Major disadvantage is low ability to remove the smear layer
• Chlorhexidine (CHX):
  • No specific information provided in the text
• Chelation agent and acids:
  • No specific information provided in the text
• Irrigation solutions with detergent:
  • No specific information provided in the text
• Hydrogen peroxide:
  • Limited antimicrobial activity against bacteria, yeasts, and bacterial spores
  • No necrotic tissue dissolving properties
  • Strong oxygen-extracting solutions should be used with caution on living tissues
• Iodine potassium iodide:
  • Low toxicity
  • May cause an allergic reaction in some patients
• Other recent irrigants:
  • QMix:
    • Contains CHX-analog, Triclosan, and EDTA as a decalcifying agent
    • Intended as an antimicrobial irrigant and for removal of canal wall smear layers and debris
    • Recommended to be used at the end of instrumentation, after NaOCl irrigation
  • SmearOFF:
    • Novel smear layer removal agent
    • Consists of EDTA and chlorhexidine gluconate

Rules to Consider During Irrigation

• Examine the relevant tooth both radiologically and clinically before treatment
• Have knowledge about the anatomy of the region
• Always use rubber-dam
• Avoid applying excessive pressure during irrigation and do not squeeze the tip of the syringe into the canal
• Use special syringe tips (30 gauge) for irrigation
• Introduce irrigation solution slowly into the canal
• Move the injector needle easily in the canal

Interaction of Irrigants

• Interaction of EDTA and NaOCl:
  • EDTA reduces the amount of chlorine resulting in loss of NaOCl activity
  • EDTA retains its calcium-complex ability when mixed with NaOCl, but EDTA causes NaOCl to lose its tissue-dissolving capacity
  • Clinically, this suggests that EDTA and NaOCl should be used separately
  • In an alternating irrigating regimen, copious amounts of NaOCl should be administered to wash out remnants of the EDTA

Smear Layer Removal

• Removing the smear layer improves the apical and coronal closure of the obturated root canal system
• The moist effect of the smear layer may have a positive effect on the adaptation of some root canal paste to the dentin wall
• Studies have reported the inadequacy of various irrigation solutions for the complete removal of calcium hydroxide from root canal walls
• Activation of the irrigation solutions used with various devices is recommended to maximize their effectiveness

Irrigation Techniques

• Manual Dynamic Agitation by Gutta Percha Cone:
  • Use of apically fitting gutta-percha cone in an up-and-down motion at the working length
  • Facilitates the exchange of the apical solution, but the overall volume of fresh solution in the apical canal is likely to remain small
• Syringe:
  • Irrigation solutions are commonly delivered using specially designed endodontic needles and syringes
  • Flexible open-ended irrigation needles are recommended to bend according to the canal curvature
  • The needle must not be jammed into the canal, and the irrigant must not be delivered with unnecessary force
  • The smallest needle recommended for root canal irrigation is 30 gauge (ISO size 30)
  • IRRIFLEX, a flexible root canal irrigation needle, has recently been introduced

This quiz covers the essential irrigants used in endodontic procedures, including saline and sodium hypocloride, and their properties and effects on surrounding tissues.