I’ve built quite a few brooches with long, green dentalium shell. I
fill it with epoxy as a reinforcing material. It does not get as
rigid as one might think and I feel that by adhering (a micro
mechanical bond) to the interior shell wall in 360 degrees, a certain
strength is achieved. I do drill and rivet through the shell, but I
never rely on the shell alone to function as a supporting structure.
While it may appear to be an integral element it is always an
ornamental feature in my work. The tips are always protected. If
any one is interested in images, I’d be happy to scan some.