Crown lengthening, build-up, and temporary crown on the same day?

[cleverwabbit]

My tooth 30 is scheduled to have a root canal treatment this week, then afterwards the next day my general dentist wants to do a crown lengthening (due to a side cavity) and do the build-up and temporary crown on it. All in one session. Then in a few weeks, he wants to place the permanent crown on it. Is this being done correctly ? . Can a crown lengthening and temporary crown be done in one session ? The literature I found on-line says that after crown lengthening, the tooth and gum tissue must heal first. Is this the proper procedure? I am very nervous about all of this dental work and am concerned because I have had some bad dental experiences and don't want to lose another tooth.
Thank you for any help.