Current guidance: YES
As of 5/26/2020, per county order, Santa Clara County dentists may return to business providing they can follow the most recent CDC guidance updated on May 19. That guidance is available on the CDC website.
Their FAQ offers further clarification as follows:
* I run a dental facility – should I continue to provide cleanings and non-urgent dental services to patients?
Dentists should follow the CDC’s guidance on dental services.
You may find their FAQ here: https://www.sccgov.org/sites/covid19/Pages/public-health-orders.aspx#healthcare