Teeth wear out. I think anyone in their forties is going to start to notice their dentition is looking a little the worse for wear. They're not going to grow back so it's downhill from there. Given the constant friction and acid, your teeth are very hardy. They should make bikes out of them.
I'm sure I've lost half my incisors to beer bottle incidents over the years. I must have started out with giant monster teeth, like a walrus or something.
I avoid dentists generally, my dentist as a child gave us fillings and pulled out her teeth to fund her secret drug habit. I'm 60% mercury because she wanted to take enough painkillers that she could believe she was a soft toy. I'm more sympathetic these days, if I had to spend all day gazing into a person's facehole I'd be shovelling whatever happy pills I could find into my own.
I should probably go and abuse my dental insurance plan and get megawatt teeth like the Americans. I'd like proper teeth, just like Jess, south London's only vampire librarian. Her teeth are magnificent and splendidly bitey.