In NZ, most dentists are part of a governing body called the Dental Council of NZ. There is also the NZ Dental Association, that provides resources and support to their members. There are also strict standards around obtaining qualifications and the process of becoming a dentist. Overseas, you have no way of knowing the dentists’ level of education, the legitimacy of their qualifications, or if they are keeping up with latest practices and standards.
NZ dentists have reported outcomes from overseas dental work such as implants placed in the sinuses, ill-fitting bridges, untreated infections, infected bone grafts, and incomplete root canals. Worst case scenario, is in the case of Melanie Heremaia from Waihi. She died two days after a root canal in Noumea—a combination of medication and tiredness. Dentists need medical qualifications because it’s a complex science and important to get right.