15 Instrumentation Errors 

Very helpful, thank you

thank you so much!!! this is much easier to understand than all of the lectures that I have listened to.

Outstanding explanations! Precise and detailed! Master piece!

thank you, very clear

I have a question. When should we use orifice opener before or after working length determination? I am asking this question because, I have used the orifice opener before WL determination and then I faced problems in WL determination because my 10 number file was loose and unstable when I engaged it with apex locator cord. This happens mostly in maxillary molars.