Under government supervision and the clinical direction of a dentist, all dental assistants may be allowed to participate in Expanded Functions training program and certification in accordance with all current and relevant BUMED and DHA instructions and local directives at the Commanding Officer's discretion. P hysical Qualifications: Beyond the general physical qualifications outlined in the base contract PWS, contract workers shall be capable of the following: Majority of dental assistants participate in four-handed sit-down dentistry, which requires somewhat regular and reoccurring back bending.