There is a book entitled " Spanish Terminology for the Dental Team" published by Mosby (2004) that comes with a CD-ROM which consists of various phrases appropriate to ask for different aspects of dentistry...You should also check Barron and other language companies to get those self-taught CDs & workbooks. But by far, the best way to improve your spanish is to be in an environment where there are a lot of spanish patients ( in certain US cities) or where the staff/assistants also speak spanish. Practice makes perfect!