Irrigation

Concentration

• Compared the biological effects of mild and strong NaOCl solutions and demonstrated greater cytotoxicity and caustic effects on healthy tissue with 5.25% NaOCl than with 0.5% and 1% solutions.
• Either 5.25% or 2.5% sodium hypochlorite has the same effect when used in the root canal space for a period of 5 minutes.
• Trepagnier et al. (1977)

• Pashley et al. (1985)

Concentration

• 5% NaOCl may be too toxic for routine use. They found that 0.5% NaOCl solution dissolves necrotic but not vital tissue and has considerably less toxicity than a 5% solution.
• They suggested that 0.5% NaOCl be used in endodontic therapy.

• Spångberg et al.(1974)