From 1921-1990 the Department of Health ran the Wellington School for Dental Nurses, which offered a 2-year Certificate. In 1952 this programme was extended with the creation of the Auckland School for Dental Nurses, and in 1956 it was again extended by opening the Christchurch School for Dental Nurses. Both Auckland and Christchurch Schools closed in 1981. In 1991, the training of Therapists was taken over by the Department of Education. Training continued in Wellington, at Wellington Polytechnic. The qualification offered was a 2-year Certificate in Dental Therapy, although in 1995 this was changed to a 2-year Diploma in Dental Therapy.