@Auste: It depends on your risk tolerance and the strategic value of the tooth. If you already have a crown and if things fail you can go back through the same access opening then risk is minimal and if things fail it can be easily mitigated. So you can take greater chances. But if a band new crown is planned then you don’t want to take chances requiring a potential need for a new access through the new crown. So, you want to be more sure and therefore would retreat. You also have to balance the risk of retreatment itself vs. taking a chance (any thin areas of dentin potentially perforating or large posts cracking roots, etc). All factors should be considered when trying to make that decision. It’s usually a multi-factorial problem. Cheers.