Irrigation Protocol Calculator

This calculator recommends the lower 2.5% concentration for vital or minimally infected cases and the higher 5.25% concentration for necrotic or retreatment cases, reflecting a common clinical tradeoff: a stronger solution dissolves tissue and kills bacteria more aggressively, which is more valuable in a heavily infected or necrotic canal, but it also carries greater toxicity risk if it's extruded past the apex.

No -- in this calculator, the recommended NaOCl concentration depends only on the case's infection status, not on how many canals are being treated. The number of canals instead scales the total volume of irrigant needed, since each additional canal needs its own adequate irrigant exchange.

NaOCl dissolves organic (tissue and bacterial) debris well but does very little to the inorganic smear layer left on canal walls by instrumentation. EDTA (typically 17%) chelates calcium in that smear layer and removes it, which is why it's applied as a distinct final rinse rather than mixed with NaOCl -- combining the two directly reduces the available chlorine and weakens NaOCl's own antibacterial and tissue-dissolving effect.

Placing the needle a few millimeters short of working length, rather than all the way to the apex, is commonly recommended in the literature to reduce the risk of forcing irrigant past the apical foramen into periapical tissue, which can cause significant pain and tissue damage. Passive delivery near, but not at, the apex still allows meaningful irrigant exchange in the apical third.