Irrigation

Effect of Citric acid

• 10% citric acid was more effective in removing the smear layer from apical root-end cavities than ultrasound.
• Gutmann et al. (1994)
• 10% citric acid was more effective in dentin demineralization than 1% citric acid, which was more effective than EDTA.
• Machado-Silveiro et al (2004)

Effect of Citric acid

• Irrigation with 17% EDTA, 6% phosphoric acid and 6% citric acid did not remove the entire smear layer from the root canal system. In addition, these acidic solutions demineralized the intertubular dentine around tubular openings, which became enlarged.
• The CO2 laser was useful in removing and melting the smear layer on the instrumented root canal walls, and the Er : YAG laser was the most effective in removing the smear layer from the root canal wall.

• Takeda et al. (1999)

• Tidmarsh (1978), who felt that 50% citric acid gave the cleanest dentin walls without a smear layer.

• Canal wall untreated by acid

• Midroot canal (citric acid)

• Midroot canal (phosphoric acid)

• Apical area (phosphoric acid)