S.D. Codified Laws § 36-6A-40
Only a dental hygienist licensed to practice pursuant to this chapter may practice dental hygiene unless otherwise stated in this chapter. A dental hygienist may perform those services which are diagnostic, therapeutic, or preventive in nature and are authorized by the board and any educational services provided pursuant to those authorized services. Such services may not include the establishment of a final diagnosis or treatment plan for a dental patient. The services shall be performed under the supervision of a dentist.
A dental hygienist may perform preventive and therapeutic services under general supervision if all individuals treated are patients of record and all care rendered by the dental hygienist is completed under the definition of patient of record. A dental hygienist may perform preventive and therapeutic services under collaborative supervision if the requirements of § 36-6A-40.1 are met. However, no dental hygienist may perform preventive and therapeutic services under collaborative supervision for more than thirteen months for any person who has not had a complete evaluation or an oral health review by a dentist.
SDCL 36-6A-40