Citric acid concentration in MTAD is:

Composition Tetracycline: – It is bacteriostatic, broad spectrum antibiotic. – It has low pH and acts as calcium chelator. – It removes smear layer. – It has property of substantivity.  – It promotes healing. Citric acid (4.25%): It is bactericidal in nature and removes smear layer. Detergent (Tween 80): It decreases surface tension.