California Registered Dental Assistant (RDA) Written Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare effectively for the California Registered Dental Assistant (RDA) Written Exam. Utilize our comprehensive quizzes and resources, featuring multiple-choice questions that enhance your understanding and readiness for the exam!

Practice this question and more.


What type of moisture control is recommended for root canal therapy?

  1. Cotton Roll

  2. Dental Dam

  3. Suction Alone

  4. Air Dryer

The correct answer is: Dental Dam

Root canal therapy involves cleaning and removing infected tissue from the root canal system to prevent further infection and save the tooth. In order to effectively do this, the area must be completely isolated and dry. While a cotton roll may provide some level of isolation, it does not provide complete isolation and does not effectively control moisture. Suction alone may also not be enough to effectively isolate the area. An air dryer, while it may help with drying, does not provide isolation and can actually blow bacteria and debris into the root canal system. Dental dam is the recommended method for moisture control during root canal therapy as it completely isolates the tooth and keeps the area dry for the procedure to be successful.