I know that both are great schools, but I believe like any other state university, UCLA would have some emphasis on research. UOP has a higher tuition, but you are done in 3 years instead of 4.
Based off your username I'm gonna assume you're from the Bay, so it would be nice to stay closer to home. Unless, you want to move away and experience what SoCal life is like. I've grown up in SF my whole life and almost all the dentists I know are from Pacific, even the one I currently work for. They do great work and do really well for themselves. If you decide UOP, then hopefully we'll be classmates since I think we both have pre-December interviews.
Goodluck with your decisions!