Have to agree with Brian (bdpreece) about Los Algodones and Dental Bernal. I've been to Dr. Juan Bernal four times and have had a massive amount of work done. Wrote a journal about my 2006 trip. Email me if you want to read thirty pages.
Algodones is a typical Gringo trap. It exists solely to service cross border shoppers. Nogales and Calexico/Mexicale have cities on the Mexican side. Walk a mile or two into the country and you will find that the deals are better ... more service ... fewer salesmen.