Ministers have refused to order head teachers to ban all sugary drinks but have insisted state schools are acting responsibly.
There are growing calls to protect the teeth of pupils by outlawing cans of pop and other damaging drinks on the playground, a move that could also cut obesity.
The British Dental Health Foundation recently urged the Government to impose a ban, praising head teachers at two schools that had acted on energy drinks.
Dinner ladies have confiscated unsuitable drinks from pupils and served water instead triggering criticism from some angry parents.
Dr Nigel Carter, the dental charity's chief executive, said: 'The increase in consumption of sugary drinks is one of the key reasons for dental decay, particularly in children.
'The foundation has supported a number of policies designed to curb sugary drink consumption from a number of health initiatives and still the Government has not acted.
'One in every four children starting school will do so with tooth decay. It may be a slight improvement compared to 10 years ago, but it's still nowhere near where we'd like it to be.'
The department for education (Dfe) told Dentistry that rules were being changed, which will mean sugary drinks will be banned from sale in more schools.
At present, they are prohibited in all local authority maintained schools and also in independent academies that were set up prior to the coalition coming into power in 2010.
Controversially, academies and free schools set up since then have not had to abide by the ban, although the Dfe insisted many had 'voluntarily committed' to do so.
With the number of non-local authority schools set to mushroom in the years to come, it created the likelihood that most schools would be exempt.
Now ministers have announced that academies and free schools signing funding agreements from this spring will be required to adhere to food standards regulations.
However, they apply only to school meals and vending machines leaving it up to individual heads to decide whether to confiscate items brought to school.
Defending the compromise, a spokesman said: 'All crisps, confectionary and fizzy drinks are banned from council maintained schools, including in vending machines.
'We encourage all schools to promote healthy eating and provide healthy, tasty and nutritious food and drink.
'We are confident that all schools endeavour to do this.
'The authors of the School Food Plan found many of the best meals were served by academies and free schools.'
Meanwhile, the Department of Health has also sought to deflect calls for a sugar tax, made by the chief medical officer for England.
A spokesman said it was making 'real progress' in persuading the food and drink industry to cut the amount of sugar in products and argued child obesity rates were falling.