@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

@Larry Loewen: Forgot the second part. Yes, BC Temp inside the canal only (not outside) and a lentulo or file can be used to place to apex. Then follow with either cotton/cavit for shorter term provisional (less than 1month) and Teflon Tape/BC Liner for longer term provisionalization (Longer than 1month).

@Jason Wu: That’s a very good question. I don’t think there are any studies directly comparing Ca(OH)2 with TCA for resorptive defect repairs. I think TCA is much more aggressive than Ca(OH)2 in causing necrosis for the resorptive cells. Ca(OH)2 causes a think layer of tissue necrosis. So, I would use Ca(OH)2 for internal resorption that has perforated (direct contact necrosis only) but would use TCA for External resorption that has spread inside the tooth (requiring deeper reach). Cheers! 🙂