Hi - I have sojerns syndrome - my mouth is very dry and causes decay. I have so many problems with my teeth, lots of cavities and I am missing some teeth and I feel it won't be long before I have none left and I am only 45. I haven't had the problem of them braking though. I would definitely see a dentist as soon as you can. I agree with Sadie, it does sound like a deficiency. Good luck!