How long does it take after root canal procedure to add permanent crown when tooth is infected and there is bone loss?

I am getting retreated for root canal after a year because the previous dentist failed to do it correctly which led to an infection and significant bone loss (2.5 mm). I've gotten two different opinions and one mentions having to wait 8 months to add the permanent crown because it is necessary to wait till the infection goes away while the other says it's a 3 week procedure.