New Zealand Dental Association President Katie Ayers said there is a high level of need for dental care among low income adults.
"Our dentists are once again generously giving their time to help those who would otherwise miss out on the treatment they need.
"In 2020 the response has been incredible, with more dentists than ever signing up, despite the hardship they have experienced themselves this year."
According to the Southern Cross Healthy Futures Report 2020, around one in five Kiwis don't seek any medical treatment when experiencing dental pain.
Dr Rebecca Yi, of Nawton Dental Centre, spoke on the initiative.
"I was inspired to volunteer after seeing so many patients put off their dental work because of cost. I am eager to see the healthy smiles on peoples' faces after I have treated them."
Dr Jason Wu, operating out of Hamilton East Dental Centre, also shared his reason for joining the programme.
"This is my first year participating in the Smile NZ Free Dental Days in Hamilton and I am excited at the chance to give back to the local community which I grew up in."
The programme has proved a great success over six years, and after this year's programme will have treated around 5000 Kiwis.
Southern Cross Health Trust chief executive Terry Moore said this illustrated that Smile NZ had made a tangible difference in the lives of thousands of people.
• UPDATE: The NZ Dental Association advised on Friday that all appointments under the scheme have now been filled. - Editor
