An abrasive filament including a matrix of thermoplastic polymer; and a plurality of abrasive particles such as eutectic alumina zirconia particles interspersed throughout at least a portion of the matrix. Abrasive brushes including such abrasive filaments are also disclosed. Methods of deburring a substrate having at least one burr, with a brush, the brush having bristles including eutectic alumina zirconia particles and a matrix of thermoplastic polymer, wherein the method includes the steps of: contacting the substrate with at least one bristle of the brush in a contact region; and inducing relative motion between the substrate and the at least one bristle.