The interviewer would like to see the types of traits you value the most. Likely, the characteristics that you mention while answering this question are going to be traits that you have. When answering this question, focus on your daily routine, personal skills, and organization skills.
"I think being able to work well in a team, clearly communicate, and consistently provide excellent customer service are incredibly important traits to have as a dental assistant. Rest assured, I would bring these traits with me to this role."
"Through my dental assistant education, I learned that the best key traits to have include a keen eye on safety, hygiene, and good bedside manner."
"I believe that a dental assistant needs to have excellent documentation skills, the ability to make a client feel comfortable, and a strong sense of safety. These are all traits that I possess and will bring with me if hired."