I haven't had dental insurance for the last year and needed a root canal. The dentist I went to said I had a tooth that needed a crown and had three roots (so three root canals), also 2 filings, and a deep cleaning. Total cost was $1800. I looked into both UCLA and USC schools of dentistry (I live in Los Angeles). The prices were only a few hundred dollars less plus it would have been a several month wait depending on when they needed to practice those particular procedures.
I finally considered going to Tijuana Mexico. I got a referral from a friend of my mother's who was very happy with her Mexican dentist. Long story short the Mexican dentist said I needed a crown but it only had two roots, didn't need any fillings, and did need a deep cleaning. Total cost (including antibiotics for the root canal) $500.
I had no problems. I drove to San Ysidro, parked on the U.S. side of the border, and walked across the bridge. At the gate I took a taxi (they are uniformed with decent vehicles) to the dental office. When I was done the dentist office called a taxi, paid the $5 fare (each way) and reimbursed me for the $9 parking fee on the border. I never walked around Tijuana. I did have to wait in line to cross back over the border and you do need a passport. Still, including the cost of a passport and gas I still paid less than half of what the U.S. dentist wanted. I had the work done two months ago and I'm happy with it.
The place I went to is called Washington Dental Clinic. It's clean and professional, just as nice as any dental clinic in the U.S. (and nicer than some). Most of the staff is bilingual and you don't need an appointment. A lo of their customers are American. This is the link:
http://www.washingtondentalclinics.com/tijuana/
Good luck. It's a tough situation. Message me if you want more info.