ST. PAUL  (AP) -- The Minnesota Department of Health has screened the oral health of a random group of third graders for the first time, and found mixed results.

The department reports that nearly two-thirds of the state's third graders have protective dental sealants on their teeth, far higher than the national average of 23 percent.

Dental sealants are thin plastic coatings that protect chewing surfaces of the back teeth from germs and food particles that cause decay.

However, the survey also found that the percentage of Minnesota students who have a history of tooth decay is higher than the national average.

More than 1,700 students received oral screenings at 40 randomly selected public schools from February to May 2010. The screenings were done by Health Department staff and volunteer dental hygienists.

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