One of NSW's leading dentists is calling on the government to "seriously consider" introducing a tax on sugary drinks.

Riverina-based Australian Dental Association NSW president Kathleen Matthews, of Wagga Wagga, believes a sugar-sweetened beverages tax would improve the Riverina's health.

"Sugar taxes have worked in other countries in terms of reducing sugar in soft drinks, by driving manufacturers to change their formula and also there's been some improvement to obesity levels in communities," Dr Matthews said.

"So that's a really important part of the puzzle when we're talking about managing a food environment."

Her comments come after the Australian Institute of Health and Welfare released figures showing almost 40 per cent of NSW residents aged over 15 years have signs of untreated tooth decay.

Dr Matthews said the NSW rate "soared" by more than a third over the past decade, a "deeply troubling statistic" she said was partly attributable to sugary foods and drinks.

The taxation of sugary beverages is a contentious issue in Australia that has been widely publicised since 2018, when a senate committee recommended it after an examination of the country's "obesity epidemic".

Because such a tax would likely be passed on to the consumer, critics say it would unfairly impact those on lower incomes.

But Australian Council of Social Service director of policy Edwina MacDonald said a tax would address the "social, health and economic costs" of the overconsumption of sugar.

Ms MacDonald said a tax on beverages should accompany regulatory reform on advertising and health promotion campaigns.

Wagga dietician Dianne Wintle said there was merit to both sides of the debate, which was more complex than whether taxation would be passed onto consumers.

"I think there's a reasonable argument to be made that, in line of when you tax cigarettes, consumption does go down," she said.

"The argument against is perhaps we need to think about who's drinking these types of drinks and would it be adding another taxation burden to the poor in society."

Business NSW regional manager Joe Townsend likened the possible effects of a "sugar tax" to the impact of the state's deposit scheme for empty drinks containers, because he said beverage companies had passed on the increase in their fees to small businesses and consumers.

A spokesman from federal minister for health Greg Hunt's office said the government does not support a "sugar tax".

"The government does not believe increasing people's cost of living is the most effective way to address obesity," the spokesperson said. "The government welcomes efforts from industry to reduce the sugar content of beverages in Australia."