California Registered Dental Assistant Examination Pass Rates:
2010: Written Examination 100% - Practical Examination 96%
2011: Written Examination 96.5% - Practical Examination 88%
2012: Written Examination 90.5%- Practical Examination 100%
Dental Board of California Passing rates: http://www.dbc.ca.gov/applicants/rda/wes2010_2011.shtml