Self-plagiarism is controversial in the academic field. Multiple submission is a well-known practice in the business (considered shady, but it's there). I'd venture a good bet that most of the clinical practitioners who present reuse with some changes tailored to the specific ask or site. I know that is specifically expected behavior (and not considered negative) for job application presentations or CMEs (as well as repetitive training). I can understand it if someone does an exact talk (which is really intellectually lazy and defeats the purpose of the education point), but I can also understand students giving adapted talks because they're already overloaded with other things.
If you give the exact talk, yes, you do say that it's a common talk, but if you're not tailoring it to the site, then you aren't doing your job in the first place. That said, it's not hard to construct a clinical talk, and you should be able to put together one quickly (as in within 4 hours for an hour talk for a base clinical audience).