Tooth preparation for RPDs should be planned on articulated study casts after they have been surveyed and a denture design ... and abrasive-impregnated rubber wheels and points are available ...

Finally, a snug fit In 1844, the invention of vulcanized -- or hardened -- rubber revolutionized dentures. The bases could now be molded to fit snugly in the mouth, and porcelain teeth ...

So they took teeth for their dentures from the bodies of tens of ... it's a compound made from India rubber. It was relatively cheap - but also pink, very nearly gum-coloured.