In a survey with an 81 percent response rate, 1980 California dental hygiene graduates reported that a large majority of dentists in 410 practices were delegating expanded functions. Hygienists reported that they were being delegated local anesthesia administration in 89 percent of their practice settings, soft-tissue curettage in 86 percent, and nitrous oxide and oxygen administration in 60 percent. More recent dental graduates delegated more frequently than older graduates. Teaching status of the dentist/employer did not appear to affect delegation. Periodontists delegated more than general dentists and this seemed to be related to patient need in those practices. Hygienists in general practices are feeling somewhat underutilized; however, they attribute a relatively small percentage (14.8% local anesthesia, 20.2% soft-tissue curettage and 4.1% nitrous oxide) of the underutilization to "lack of delegation" by their dentist/employer. Hygienists perceived "lack of patient need" and "lack of equipment" to be the major reasons for any underutilization in the expanded functions. In conclusion, it appears that a 1976 law change in California allowing dental hygienists to perform block and infiltration local anesthesia, soft-tissue curettage, and nitrous oxide and oxygen administration has resulted in a rather widespread change in the dental practices of this sample. Dentists are apparently delegating local anesthetic administration and soft-tissue curettage in over 85 percent of the 410 practices employing 216 hygienists. Delegation of nitrous oxide and oxygen administration, which is dependent on availability of equipment, was reported as being delegated in over 50 percent of the practices.(ABSTRACT TRUNCATED AT 250 WORDS)