Neither Roxanne nor Salvador mentions any substances that can substitute for ivory. The discussion is about antique versus new ivory, not ivory versus something else.

Roxanne claims that the demand for antique ivory is unrelated to the demand for new ivory. Salvador argues that lowering the demand for antique ivory can lower the demand for new ivory by redirecting some buyers. This is the point of disagreement.

Roxanne and Salvador both discuss only what people should do if they want to help protect elephants. Neither directly states that people should protect elephants, but it would be fair to assume that they both agree it’s a good idea. Either way, no disagreement here.

Neither speaker talks about how impactful a refusal to buy new ivory would be. Even Roxanne, who proposes a boycott of new ivory as a way to protect elephants, doesn’t specify how much this could do to help the species.

Roxanne agrees with this, and so does Salvador. Roxanne states that people with this concern should not buy ivory less than 75 years old. Salvador goes even further and says that those people should not buy any ivory at all, which includes new ivory.