"The Prime Minister is working from home for now but is doing fine," a spokeswoman told the New Zealand Herald.
Ardern had an operation on an impacted wisdom tooth on Friday night and will miss today's Cabinet meeting.
But she is still hoping to attend a Council of Trade Unions event in Auckland tomorrow night.
Last week, Ardern told reporters that she has had issues with her wisdom teeth for three years and was about to have an operation to remove one more.
"I apologise. That's more detail than any of you would have liked – and more than I'd like to share, but I didn't want to start any speculation," she told reporters unprompted a week ago.
She did not say how much the operation was going to cost, but added that she had not yet had a final quote – "I know that it will be reasonable".
The surgery will affect a part of the bone in her jaw, she said, adding that she had been advised that she should be off work for "several days".
Ardern also confirmed that there was not, in fact, a special dental clinic for prime ministers in New Zealand.
"Despite the fact that I've had plenty of commentary – more than others probably about my dentistry over the years – I just go to the dentist like anyone else."
Asked if it was too expensive for people to have their wisdom teeth removed, Ardern said accessing dental work in general in New Zealand is an issue.
"Every time I go to the dentist, I reflect on that.
"But as we [the Government] have said, we actually have a number of areas where we know we need to make the health system – and that includes [making] public health – more accessible."
But she said it's all a matter of how the Government is able to prioritise making those parts of the health care system more accessible.