Almost all Americans have tooth decay, and less than half of Americans under the age of 65 still have all of their teeth, says a report from the Centers for Disease Control.

"Approximately 91 percent of U.S. adults aged 20-64 had dental caries in permanent teeth in 2011-2012," the report stated. At the age of 65, 96 percent of Americans have had tooth decay.

"It is not what people are doing wrong. It is maybe what we can do better," said study leader Dr. Bruce Dye of the National Institute of Dental and Craniofacial Research.

A lot has to do with access to dentists, says NBC News. People without dental health coverage or those who live in areas where there are few dentists are more likely to have tooth decay, and are more likely to go without treatment when living in areas where dentists are not common, are more likely to have tooth decay, and less likely to get fillings.

"The prevalence of untreated dental caries was nearly twice as high for non-Hispanic black adults (42 percent) compared with non-Hispanic white (22 percent) and Asian (17 percent) adults," wrote Dye and his colleagues.

They used a national survey of tens of thousands of Americans, called the National Health and Nutrition Examination Survey, for their report.

About 19 percent of people 65 and over have no teeth at all. This rises to 26 percent of people 75 and older.

The recent report looked at adults. An earlier study found that 42 percent of children ages 2 to 11 have had tooth decay, and 23 percent of them had not been treated.

According to the American Dental Association, the following tips help prevent tooth decay:

• Brush twice a day using fluoride toothpaste.

• Floss daily.

• Eat a healthy diet and limit snacks.

• Consider using supplemental fluoride and dental sealants.

• Have regular dental checkups.