Dental cement – any that are bad??

I had a small bridge in the back of my mouth that came off……it was loose when she put it on permanently. I saw on HOUSE that certain dental creams contain too much zinc..the woman was using it too often. BUT it made me wonder if there are permanent cements that contain harmful substances that we should avoid. Anyone know? With GBS we need to baby and protect our bodies from future stress or harm. The bridge has not stayed on longer than 7 months…but I did not want to get an implant because of having had GBS recently.