Broken teeth

So during my pregnancy my teeth pretty much fell apart. I broke two molars and got quite a few cavities. After having my daughter I went to the dentist last week and was told I need 2 root canals on the broken teeth and one on a tooth with a bad cavity. I am scheduled for May 24th to have this done. Long story short I just broke the one that wasn't broke so now I have a broken tooth on both sides on the top and one on the bottom. They are all molars. Question is has anyone ever used the dental cement or whatever it is? I was thinking of getting this because I am scared to chew anything now and with me breast feeding I need to eat! I was just wondering does this stuff work until hopefully they can get me in sooner at the dentist? I am wondering if it destroys your tooth more and how does it come out?