billing for crown not yet performed

hi, i would really appreciate some professional insight into the following. I visited a new dentist on a Monday due to severe tooth pain and was advised i needed a root canal on #11 and #12 asap, but they did not have an available appt until 2 weeks out. Luckily, they called me two days later to fill a cancellation. I had both root canals done that day, and afterwards was advised i owed for my portion of the root canals (which i was expecting), but also for my portion of the crowns as well (which i was not expecting and couldn't pay in entirety). My insurer has been billed for the crowns now and have paid, but i find this unsettling that they billed in advance for a procedure not yet performed and have already been paid. They state that until my portion is paid they will not even order the crown, and that once they do order it, it will be three weeks before they receive it. Please advise me if this is standard practice. I am not trying to shirk my debts, but i am feeling really uncomfortable with how this is being handled. I just want to know if this is an industry standard.  

[lynn117]

i guess all dentists have different policies. i dont have insurance and sometimes i have had to pay it off a little each month but usually i pay either as the work is performed or at the final visit whichever i choose. i find it odd that if the policy was to pay in advance you werent informed at your first visit. i would ask why they do this and explain that your not comfortable. my friend is dealing with a chain dental practice that demanded prepayment for her partials. she paid and now they dont fit correctly and are the wrong color but they claim its the best they can do. when she got agitated she was escorted from the office. if your dentist can not explain why you must prepay to your satisfaction go somewhere else.