3M (NYSE:MMM) is not taking kindly to a pair of European companies it claims are appropriating its intellectual property. The company announced that it has filed two patent infringement lawsuits in Germany against two local concerns, Metoxit and White Peaks Dental Systems. 3M is alleging that both firms infringed its patents for coloring liquids used in ceramic-based dental restorations.

In the case against Metoxit, it asserts that the company infringed its Z-CAD, FlowPen, and Z-CAD Liquid HD coloring products, in addition to zirconia CAD/CAM blocks sold under the Z-CAD name. With White Peaks, 3M feels that that firm is guilty of infringing the rights connected with the coloring liquid brands CopranColor, Copran Ultra-T Color, MonolithColor, as well as zirconia CAD/CAM blocks sold under the Copran Zr name.

3M said it licenses its various dental coloring patents to a number of companies in Germany.

In 2012, 3M's international sales totaled $19.4 billion, or 65% of total sales. 

Fool contributor Eric Volkman has no position in 3M. The Motley Fool recommends 3M. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.