Electric toothbrush bristle pattern

FIG. 1 is a front elevation view showing the electric toothbrush bristle pattern of our new design;

FIG. 2 is a left side elevation view thereof; the right side elevation being a mirror image of the left side elevation as shown herein in FIG. 2;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a perspective view from the front left side thereof.

The body of the electric toothbrush in the above Figures is shown in broken lines for illustrative purposes only and forms no part of the claimed design.