I answer and they told me that it was from Dental Works and explained the situation for the call.
I call back 2 minutes after, and the telephone company told me that that number does not exist.
I needed to know more details about the call, and it was imposible to call back.
My next step will be to call "DentalWorks" under their listed number and find out what is all about.
I will post back under my name " Paco".