NZ First wants to expand free dental care for 18 to 25-year-olds, Community Service Card holders and Super Gold Card holders by providing a yearly free check-up, x-ray and clean.
Currently, children in New Zealand get free basic dental care up until their 18th birthday.
NZ First wants to then provide means-tested free dental care to everyone under 26, parents and caregivers, pregnant women and people aged 65 and older - "then to everyone else".
"It's seriously bad," leader Winston Peters said of the state of accessibility to dental care in NZ. "It's seriously needed."
"It is affordable if it's on a means-tested basis."
It was estimated by NZ First to cost $515 million each year.
"When I see money tossed around like an eight-armed octopus in other areas and given the fact we probably treat animals, in terms of their dental care, better than we do humans, we need to address this and address this now," Peters said.
National last month pledged a $30 million boost annually to go towards children's oral health, calling the current children's dental policy "underfunded and not comprehensive".
Labour this week promised to increase the emergency dental grant from $300 to $1000, available for the lowest earners.
Asked if Labour's policy was enough, Peters said it was "way short of what's required".
"If you look at all the areas of expenditure, we need to focus and narrow down on some of the critical areas. Dental health is a serious one, now."
According to the latest round of data from TVNZ’s Vote Compass tool, the majority of New Zealanders think the Government should fund dental care for adults who have lower incomes.
In February, a 1 NEWS Colmar Brunton poll showed almost two-thirds of New Zealanders were in support of the Government prioritising free dental care.
Dr Assil Russell of Revive a Smile told 1 NEWS at the time the Government needed to step up and said a targeted, subsidised approach would make a "huge difference to a lot of people's lives".