Victorian students will get free dental treatment - saving families hundreds of dollars in health costs - as part of a $322 million cash splash in Monday’s state budget.

But the new fleet of dental vans will take almost three years to roll out to every public primary and secondary school, won’t apply to students in the Catholic or independent sectors, and will require more staff to be trained and recruited.

This week's Victorian budget will bring back school dental vans. Credit:actemma.kelly

With figures showing a quarter of Australian children have tooth decay, Premier Daniel Andrews will on Sunday announce that a so-called "Smile Squad" will start visiting schools in Box Hill, Barwon South, Cranbourne and Wodonga from term 3 this year.

The vans will be rolled out to all Victorian public schools by 2022, providing students with free check-ups and as well as teeth cleaning, fillings, root canals, extractions, and fluoride applications. Cosmetic and orthodontic work will not be covered.