FIG. 1 is a left, frontal perspective view of a toothbrush showing my new design;

FIG. 2 is a right, rear perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right side view thereof, the left side view being a mirror image thereto;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a top view thereof.

The dashed lines are for purposes of illustration and form no part of the claimed design. The stippling in the Figures represents a difference in appearance by color, texture, and/or material.