By Jonathan Stempel

Jan 8 (Reuters) - Procter & Gamble has begun rolling out new packaging and marketing for Crest children's toothpaste under an agreement with Texas Attorney ​General Ken Paxton, after he expressed concern that encouraging excessive fluoride use could ‌harm children.

Paxton said Procter & Gamble will ensure that its packaging and marketing for Kid's Crest "clearly depict the appropriate ‌amount" of toothpaste for children.

He said the roll-out began on January 1, and Procter & Gamble must maintain compliance for five years.

Procter & Gamble, based in Cincinnati, said it was "fully committed to delivering safe, reliable products that benefit the oral health outcomes of our consumers," and "voluntarily agreeing ⁠to ensure that our artwork reflects ‌recommended dosing levels for children."

Colgate-Palmolive reached a similar agreement with Paxton in September for its Colgate, Tom's of Maine and hello brands of ‍toothpaste. That company agreed to depict "pea-sized" amounts of toothpaste, rather than large swirls, on labels.

In October, a federal judge in Chicago rejected Procter & Gamble's bid to dismiss a private lawsuit saying it ​violated state consumer protection laws by depicting a full strip of toothpaste atop a ‌toothbrush, with a seal of approval from the American Dental Association, on Kid's Crest labels.

Paxton issued civil investigative demands to Procter & Gamble and Colgate last May, accusing manufacturers of flavoring and marketing fluoride toothpaste in ways that cause children to ingest the product and parents to let children use unsafe amounts.

The Republican has aligned himself with the Make America ⁠Healthy Again movement associated with U.S. Health and ​Human Services Secretary Robert F. Kennedy Jr, who opposes ​adding fluoride to public water systems.

Fluoride strengthens tooth enamel and helps prevent cavities, and the ADA supports fluoridation of toothpaste and drinking water.

Last January, ‍a study published in ⁠JAMA Pediatrics linked higher fluoride exposures in children to lower IQ scores. But a University of Iowa dentistry professor criticized that research in an accompanying editorial, and warned ⁠against changing public policy concerning fluoride based on the findings.

Paxton is running for the U.S. Senate this year, ‌and hopes to unseat Republican incumbent John Cornyn.

(Reporting by Jonathan Stempel in New ‌YorkEditing by Tomasz Janowski and Diane Craft)