We go to a pediatric dentist in San Ramon. He has been the kids dentist since they got their teeth. I have never discussed their Do with him. The kids love him. They even recognize him outside if the office and say hi.
We're in San Jose- we drive about 45 minutes to go to a dentist that was suggested to us by a family friend. His practice works with many autistic kids, and he's quite great. It really does make a big difference to have someone trained and practiced at working with our kiddos. Our son completely hates dentists- but they're great at handling his issues. Try running a search for "pediatric dentists for autistic children" (or something akin to).... something might pop up! Good luck.