Can I use foam or polystyrene plastic cups? Stephanie November 27, 2018 21:36 Updated Follow Avoid using foam cups because polystyrene plastics will not hold up to the menthol in this product. Related articles Can I use a Water Pik with OraMD? How can OraMD get to the bacteria deep in the gum line? Should I rinse my mouth out after brushing with OraMD? Are there any side effects from using OraMD? Comments 0 comments Please sign in to leave a comment.