DEH 2900 - Dental Hygiene Competency Review DEH 2900 - Dental Hygiene Competency Review (1 to 3 variable Credit Hours) (A.S.) One to three hours of didactic instruction per week or four to 12 hours per week of clinical practice. This course is designed to meet the needs of students who either wish to re-enter the program or a graduate student who desires clinical updating and competency review in preparation for the clinical licensure examination. Additional special fee is required. View class scheduling information for this course.