I've been puffing with my e-cig all day, everyday, for about a month. For the last week I have had three teeth just start to brake apart while I'm eating. I believe I'm grinding my teeth during sleep. Nicotine can cause this, since it is a stimulant. But with an e-cig I'm puffing a great deal more, and probably getting more nicotine. Has anyone else experienced this? ...for the record I still consider e-cigs a million times better than 'real' ones.