WASHINGTON, D.C. ? Government health advisers rejected a federal report that concluded dental fillings used by millions of patients are safe, saying further study of the mercury-laden amalgam is needed.

A joint panel of Food and Drug Administration advisers did not declare the so-called “silver fillings” unsafe. But in a 13-7 vote Thursday, the advisers said the federal report didn’t objectively and clearly present the current state of knowledge about the fillings.

In a second 13-7 vote, the panelists said the report’s conclusions about safety weren’t reasonable, given the quantity and quality of information available.

The FDA had asked the panel of outside advisers to weigh the report, a review of 34 recent research studies.

The report had found “no significant new information” that would change the FDA’s earlier determination that mercury-based fillings don’t harm patients, except in rare cases where they have allergic reactions.