ANCHORAGE, Alaska (AP) – Dental decay among rural Alaska Native children is as much as 4 1/2 times greater than children in the general U.S. population, according to a new report by the Centers for Disease Control and Prevention.

The CDC and Alaska state health officials released the report Thursday that details the findings of a 2008 investigation. The state also worked on the report.

The study found that soda pop consumption and lack of water fluoridation are primary factors associated with dental decay in both baby and adult teeth.

“The number one emphasis of this article that we're looking at is the role of fluoridation. Most parts of rural Alaska are not fluoridated,” said Brad Whistler, the state's oral health director and one of the authors of the report.

Five rural Yupik communities in a 52-village region took part in the study, three with non-fluoridated water and two with fluoridated systems. The area was not named in the report and state and CDC officials declined to identify it, saying they were asked by the regional tribal health organization not to reveal the area to avoid becoming stigmatized.

“And really, the results that we find could be applicable to a large number of rural communities in Alaska where dental decay is a severe problem and water fluoridation is generally unavailable,” said study participant Tom Hennessy, director of the CDC's Arctic Investigations program.

One of the other participants named in the study is Joseph Klejka with the Yukon-Kuskokwim Health Corp. in Bethel, the commercial hub for several dozen western Alaska villages. Klejka did not immediately return a phone call seeking comment Thursday.

Altogether, 348 children between the ages of four and 15 were screened and parents were surveyed to determine risk factors.

According to the report, children between the ages of 4 and 5 averaged more than 2 1/2 times more decayed and filled baby teeth in Alaska villages with non-fluoridated water than children of the same age in villages with fluoridated water.

Only four communities in the region have fluoridated water systems, according to the report, and another 16 don't have residential piped water systems necessary for fluoridation. The study noted options to fluoridated water include brushing with fluoridated toothpaste and fluoride varnishes applied to teeth.

Most of the villages in the region have piped water in homes, thus communities have the equipment in place for fluoridation. Adding fluoride could prove cost effective, with studies showing that every dollar spent on fluoridation equals up to $38 saved in health benefits per person, Hennessy said.

“For many communities that have piped water systems, fluoridation is an option and they're choosing not to take that on,” he said. “This report really speaks to those communities.”

Dental decay among Native children has worsened while it has decreased among most age groups nationally as a result of fluoridation, according to the report.

Archaeological evidence suggests that only 1 percent of the Alaska Native population had dental decay in the 1920s, but the rate has been climbing since the air transport of processed foods became more frequent starting in the 1940s.

A federal Indian Health Service survey showed that 64 percent of Alaska Natives – and American Indians – between the ages of six and 14 had tooth decay by 1999. Six years later, an Alaska state study found that 75 percent of Alaska Native kindergarteners had dental decay.

In the new CDC study, 87 percent of 4- to 5-year-old Alaska Natives screened had decay, compared with 35 percent for the general U.S. population for that age group. Alaska Native children in that category had a mean of 7.3 teeth affected by decay, compared with 1.6 teeth nationally for children of that age.

According to the report, about 400 children in the 52-village region had full-mouth dental rehabilitations requiring general anesthesia in 2007 in an area averaging 600 births a year.

The following year, state health officials asked for the CDC study on behalf of the region.