Study design The investigation is designed as a double blind, parallel group, and randomized trial over a 3-months period (primary endpoint). Secondary endpoints are not scheduled. Seventy-five subjects will be enrolled in this four-visit study; visits 1-4 are required for each subject. Test and control group subjects will be treated following identical therapy protocols, except for the dentifrice. Participating study centers will be the Department of Periodontology at the University of Münster and the Department of Periodontology at the University of Würzburg.