3M Co. has sued Kerr Corp., claiming that two of Kerr's dental-composite materials infringe on 3M's patent rights, company officials announced Monday.

Officials from California-based Kerr could not be reached for comment.

3M's lawsuit alleges that Kerr's SonicFill 2 and Harmonize dental-composite materials copy the patented nanotechnology 3M developed for its 3M Filtek Supreme universal dental restoratives.

3M officials said 3M's Filtek dental materials have been used in 600 million tooth restorations and are known for realistic aesthetics, strength and resistance to wear. The products are made by 3M's Innovative Properties Co.

"As an industry leader, we are committed to protecting our innovative nanotechnology and associated intellectual property," said Eric Wenzel, global business director of 3M Oral Care Solutions.

Kerr's company website said it introduced its "lifelike" Harmony nanoparticle restoration composites in November 2016. The SonicFill 2 product has been marketed at least since 2015 as a way for dentists to fill cavities in molars with a single application.

3M's lawsuit against Kerr is the latest in a number of claims against competitors alleging patent infringement.

In recent years, 3M filed three patent-infringement lawsuits in Germany in regard to its dental technology.

One suit, against Dental Direkt GmbH, started in December 2008 and was finalized in 3M's favor last year.

3M's lawsuit against Metoxit AG, alleged infringement regarding coloring liquids or zirconia blocks sold under the brands Z-CAD FlowPen, Z-CAD Liquid HD and Z-CAD. 3M has settled that lawsuit, and Metoxit AG is now licensed to use the technology.

Last year, 3M also settled a suit against White Peaks Dental Systems GmbH & Co. KG.

In 3M's announcement Monday, it was not immediately clear if 3M is seeking a court cease-and-desist order, licensing fees, sales royalties or some other remedy with regard to the technology.