there are plenty of post bac programs here in Cali. Many many pre-health and pre-med post bacs. I think almost every school had one... Some I know for sures in the Bay Area that I am considering myself is San Jose State, SF State and Cal. Plenty of others out there if you just check out the schools website.
I just realized you mentioned dental post bacs. Not sure about that but any of the pre-med post bacs should be good for dental school.