It turns out that Gatorade (and like drinks) can erode teeth faster than Coke or Red Bull, even though the sugar content isn't as high as a soft drink*. Does this mean we should floss at every aid station? Probably not, but you can take steps to decrease the likelihood that your next dentist visit will involve drills and novacaine. Blogger Mark Iocchelli has some great suggestions based on a similar experience he had at the dentist.
This isn't the first visit to the dentist that involved a long discussion about trail running. In 2004 when I was doing a lot of short-course running, I noticed I had jaw pain the morning after the races. It turns out that I was clenching my teeth while racing (and I did a lot of racing that year), to the point it had ground my molars down to nubs over a 10 month period. My molar alignment looked like Stonehenge, which made my bite uneven and in turn created increased jaw pain when I clenched my teeth during the next race. I probably didn't notice this while racing since it was drowned out by my bursting legs and lungs, but I definitely could feel the ache in my head the next day. I asked the dentist if this meant I needed to stop running and he said, "no, you just need to relax more".
That turned out to be some of the best coaching I had all year. ;-)
The two 1/2 days in the dentist chair to get my bite back to normal was more than enough incentive to investigate what was causing the clenching. It didn't take long to figure out that it happened most often when I was racing downhill. Part of the stress came from the fact that I rarely trained running downhills at full speed, so at race time I would get nervous when entering steep downhill sections. Ironically, I could fix this by adding MORE downhill sessions to my training, such as a few 1-2 minute downhill bursts 2-3x/week with a focus on running relaxed (I always think of "leaping" and "letting gravity pull me down", which is a much calmer mantra than "charging the hill"). After 3-4 weeks, I was not only running more relaxed, but I was runing smoother and going faster.
At my check up, my dentist said it was obvious that the clenching had been minimized. Another factor was that I moved up to the ultra distances, where white-knuckle downhill bombing isn't quite as common. Unfortunately, this also means I am drinking a lot more energy drink. So I guess I just keep a toothbrush in my fanny pack for the long runs...
* Note that this same article points out Gatorade-sponsored studies showing that there is no incremental damage, much in thanks to increased saliva production. Perhaps the effect isn't as dramatic as the latest studies show.