I don't really know of any pre-dental podcasts, and I'd be shocked if any pre-dental students listen to podcasts anyways, lol. I was always more inclined to watch youtube videos of dental students talking about their day-to-day stuff or talking about how to apply and be a competitive applicant. Of which there is a lot of content on youtube.
Actually, thinking more about it, there's a dental student on youtube by Stephen Ray who attends UTennessee Health Sci and is going to be a D4 soon. He has a podcast he runs. I have yet to listen to any of them, but the other material he puts out on his youtube is great, and he interviews students from other schools. I would instruct your pre-dents to check his channel out. I believe he has his pod-casts on youtube too, but I choose to watch his other material