I have noticed on multiple occassions that under conditions of extreme exertion (i.e., exceeding my textbook maximum heart rate), I get pain in my mouth, almost like every tooth has an infected cavity. I had always just found it an interesting effect. But, in reading this, I presume that elite athletes are in such states far more often than I, and that whatever the underlying mechanism is that causes the pain might also be deteriorating the dental health. I've never been able to find a plausible explanation of the effect that tracks with my actual circumstances (i.e., as far as my dentist and I can tell, I have excellent dental health, but I am not an elite athlete, just a weekend warrior who sometimes overdoes it).