Health authorities are urging anyone who has had dental treatment from Mangere man Sione Heinave Vailea to contact a hospital as soon as possible.
Counties Manukau District Health Board said Mr Vailea was not registered in New Zealand as a dentist or dental therapist and was not permitted to perform dental surgery or to provide medication to patients.
The DHB's spokesman Clive Ross said Mr Vailea was arrested yesterday and was facing 12 charges in relation to practising without certification and issuing prescriptions.
Mr Vailea had undertaken some dental therapy training but was not registered as a dental therapist and therefore not a qualified dentist, he said.
While it was not known how long Mr Vailea had allegedly been performing dental work, investigations by police and the DHB had revealed allegations that he had been treating patients for many years in his home for a variety of dental treatments including fillings, extractions, denture work, and gold inlays.