@Larry Loewen: That’s a great question! If you have a continued release of Ca(OH)2 over a longer time period, your odds of penetrating deeper into the dentinal tubules and slowly breaking down the biofilm, especially in more resistant species is higher. It’s like using a bacteriostatic medication for longer time period. Also, E. recalls, is resistant to Ca(OH)2 as it has a calcium pump that throws off the calcium. But over longer time periods this will be disabled and the bug will eventually be killed. Also, for cases of apexification or other factors where you need to wait for asteoid formation the longer term is needed. But for the run of the mill necrotic canal, why 3 or 6months vs. 1 or 2 months is probably better answered by Dr. Ricucci who is the proponent of longer term therapy. I will try to ask him that question and will hopefully get back to you if he answers. 🙂
Cheers,
Ali