An Expanded Functions Dental Assistant (EFDA) plays an important role in a dental office, preparing duties that include patient, chair and administrative work. Each EFDA is required to have state and radiology certifications, in addition to meeting the necessary guidelines to work in this field. Their responsibilities may include, preparing treatment rooms before procedures, reviewing dental records, ensuring each patient is comfortable and taking and developing x-rays. An EFDA may also provide technical assistance to the pediatric dentist, such as applying anesthesia or pain medication during a cavity filling.