Bridges said he respected her opinion but disagreed on fluoride and that it should be the District Health Boards that control whether water supplies are fluoridated.
"I got to tell you personally I'm in favour of fluoridisation. I want to see it in my area because I've got three young children and I want their teeth to be good."
On transport, Bridges told the audience they were being taxed more as part of the regional fuel tax and receiving less with reduced investment into roads in the area.
"We would have continued that road of national significance up to north of Levin ... we promised, as a pledge, we would take it further north - potentially to Sanson.
"I look at Whanganui and it's this simple right ... if you don't have decent transport infrastructure none of the rest matters.
"Whanganui's got a great future but what it needs is connectivity into the lower North Island and ultimately to the upper North Island where the population base is."
There were very few young people in the audience and this was pointed out by one attendee who told Bridges he was preaching to the converted.
"You're right," he said.
"In this room I would say probably half are strong National supporters. What I'm finding all around New Zealand is there are a lot of people who just come a long because they want to have a look.
"We've got to reach people in all manners of ways. We just keep doing that by wood or on stone."
On education, Bridges criticised the Government's fees-free programme and said the money would be better spent in younger age schools.
On the End of Life Choice Bill, Bridges said it was one of many conscience issues on the table for MPs.
"I have always been relatively socially conservative on these issues.
"I voted against euthanasia ... firstly I believe in the sanctity of life. It is very unlikely to see me change on that. I understand people in pain, I understand the complexities of it.
"The second reason is ... in other countries where they've done this it starts very narrow but it widens quite significantly. You see young people, people with depression being able to go through the euthanasia process and I don't agree with that."
After an hour and a half taking questions, Bridges concluded by thanking those in attendance and heading to Hawera, where he got a similarly sized audience.
After that, Bridges finished with talks in Inglewood and New Plymouth.
He'll be in Taumarunui and then Putaruru today.