A survey shows 96 percent of dentists say they are having to fix poor dental work done overseas.
Otago University surveyed 337 dentists who said they dealt with "dental tourists" at least once or twice a year.
Thailand is the most common destination for dental treatment, with nearly 90 percent of patients being treated there, followed by India and Indonesia.
The New Zealand Dental Association's chief executive David Crum said he had witnessed the effects of dental tourism.
A few months ago, a patient returned from Thailand with nearly every tooth crowned.
"They were so bad the gums were all bleeding, with all the food that was collecting. Apart from suggesting that they all be redone or sending her back to Thailand, the only other option was to accept that she will lose her teeth," Dr Crum said.
He said the low cost was appealing to tourists.
"But when you do that and you arrive somewhere and the cure's provided within a few days with very little pre-planning by somebody you've never met, then you leave the country and come back to New Zealand, who looks after that work? Who maintains it? What happens if it hasn't been done well?"
He said he wasn't raising the issue to protect New Zealand dentists and that people had the right to go overseas but it was about "doing that with the knowledge that somebody needs to look after that work when you get back".
About 15 percent of respondents said dental tourism would impact negatively on their incomes, while six percent felt it would increase their income due to increased demand for remedial treatment.
The research was published in the journal of Tourism Management.
- 6 percent of dentists surveyed said dentist tourism enhanced dental health outcomes for their patients
- 1.9 percent would recommend it to their patients
- 21.8 percent agreed that dental tourism should be discouraged due to its negative impact upon New Zealand's dental healthcare system