There are ethical issues associated with using models to teach medical procedures. Typical ethical questions trade-off the realism of the model against the rights of the model, taking into account the distribution of resources.
Plastic models have no rights.
The ethical issues associated with plastic models are those of resource distribution and skills transfer. The use of food animals for teaching procedures raises many of the same moral issues as does the use of animals for human consumption or clothing. Procedures commonly taught using parts of food animals include intraosseous needle placement in chicken legs and suturing of pig or turkey skin. The use of non-food animals raises issues not only of animal rights or suffering, but also didactic issues. Small animals are so different from humans that they almost are useless for teaching medical procedures.