Treatment of severe periodontitis may improve clinical disease activity in otherwise treatment-refractory rheumatoid arthritis patients by Möller, B, Bender, P, Eick, S, Kuchen, S, Maldonado, A, Potempa, J, Reichenbach, S, Sculean, A, Schwenzer, A, Villiger, P, Wong, A, Midwood, K