x-rays from the dentist

I have the old kind of x-rays from my dentist.  How do I convert them into digital form so a friend of mine in China can take a look at my x-rays? 

Also, if I qqh a dentist on this forum, do you think that is approraite?  I mean, they are all busy, and I have never talked to any one of them before. 

非常感謝