Volumetric measurement of the root canal space before and after root canal treatment

Operating system: MacOS 14.3.1
Slicer version:5.6.1
Expected behavior: defined volume of root canal space
Actual behavior: sliced model of the tooth , but no separation for pulp space

Hi everyone,
I am very new to the 3D Slicer, and I’m learnig my steps in using it.
I’m conduting a scientific research to compare various irrigation and obturation techniques in endodontic treatment. To do that, I plan to compare root canal system volume with the obturation material volume and void spaces left. I have High resolution CBCT scans at the moment and in couple weeks I will have some micro-CT scans too.
Is there a way of doing it in the 3D Slicer? Program has so many advanced options that I would appreciate any help and guidance.
Is there en effective and relatively quick way of doing it?

Thanks
Jacek