Filament for an oral care implement and oral care implement

A filament for an oral care implement comprising:

• the filament having a longitudinal axis and a substantially cross-shaped cross-sectional area extending in a plane substantially perpendicular to the longitudinal axis, the cross-shaped cross-sectional area having only four projections and four channels, the projections and channels being arranged in an alternating manner, the cross-sectional area having an outer diameter, and each channel having a concave curvature formed by neighboring and converging projections, the concave curvature having a radius, wherein
• the radius is within a range from 0.015 mm to 0.12 mm, the outer diameter is within a range from 0.22 mm to 0.40 mm, and the ratio of the outer diameter to the radius is within a range from 2.5 to 12.