If you've ever endured a dental filling based on the advice that there's no other way to stop tooth decay before it gets worse, you may be a bit, well, annoyed when you hear about the latest study on this topic.

In a seven-year study involving 1,000 patients at 22 dental practices, researchers at the University of Sydney compared people who received traditional "drill and fill" treatment with those who received a less aggressive preventive treatment that involves high concentration fluoride varnish and restricting sugary snacks and beverages between meals.

They found that for those in the second group the need for fillings declined by 30 to 50 percent. Among those at highest risk, who were getting as many as two fillings per year, the reduction was even greater -- 80 percent.

The conclusion, according to lead author Wendell Evans, is that much decay can be stopped, reversed, and prevented with simple treatments: "It's unnecessary for patients to have fillings because they're not required in many cases of dental decay."

The results, published in Community Dentistry and Oral Epidemiology this week, signals that a major shift may be needed in how dentists treat early tooth decay, the researchers said.

Current dental practices are based on the assumption that tooth decay is rapidly progressive -- and possibly inevitable. If that were the case it would make sense to identify decay early and remove it by drilling and filling. But newer studies show that decay develops more slowly, an average of four to eight years to progress from the other layer of the tooth's enamel to the inner layer where it can do the most damage.

"That is plenty of time," the researchers said, "for the decay to be detected and treated before it becomes a cavity and requires a filling."

Unfortunately, if the decay has already formed into a cavity, there's really no way to avoid the filling.

Read more:

Chipotle CEO pledges to make restaurants ‘safest place to eat.’ Here’s his plan.

Netflix binge-watchers beware: Watching too much TV in your 20s may impact how your brain works in mid-life, study suggests

With $45 billion pledge to charity, Mark Zuckerberg and wife imagine ‘a world without suffering from disease’

The myth of sugar-free drinks, candy: Study shows they can wreak havoc on teeth, too

Modern men tend to overeat like cavemen as a way of showing off to women

For more health news, you can sign up for our weekly newsletter here.