Preventing Accidents with Demonstration Casts
When plaster casts are usedfor table clinics, case presentations,or other demonstrations,there is always a possibilitythat they can be dropped,breaking some of the teeth, orunintentionally rearranged. Ihave found a way to keep castson the table by implanting magnetsin their bases.
Small magnets made ofsamarium cobalt or neodymiumiron boron can be used. To preventcorrosion, cover each magnetwith a sheet of polyvinylchloride in a vacuum-formingmachine. Make a hole for themagnet in the base of the cast(Fig. A), then insert the magnet, andplaster over the hole. The patientidentification label can be addedto cover the repair site (B).
To prepare the table, affixsome self-adhesive double-sidedstickers in the locations for thedemonstration casts. Cut thinstainless steel bases to the sizeof the plaster cast bases, andstick these to the table with theadhesive (Fig. C). Set the casts overthe stainless steel bases so thatthe magnets hold them in place(Fig. D). The same procedure can befollowed to place the casts in anocclusal view (Figs. E,F).