Use of a morpholino compound having the general formula (I) wherein R1 is a straight or branched alkyl group containing (8) to (16) carbon atoms at the 2- or 3- position of the morpholino ring, and R2 is a straight or branched alkyl group containing (2) to (10) carbon atoms, substituted with a hydroxy group except in the alpha-position, or a pharmaceutically acceptable salt thereof, in the manufacture of a medicament for the treatment of an infected sub-gingival pocket.