The ornamental design for a 3 sided fingerbrush for oral hygiene, as shown and described.
FIG. 1 is shown on a reduced scale and the broken line showing of a user's hand therein is for illustrative purpose only and forms no part of the claimed design. The broken lines showing a series of bumps illustrate portions of the finger brush that form no part of the claimed design.
FIG. 2 is a alternate perspective view of this invention
FIG. 3 is a front elevation view of this invention
FIG. 4 is a rear elevation view of this invention
FIG. 5 is a side view of this invention
FIG. 6 is a top view of this invention; and,
FIG. 7 is a bottom view of this invention.
The broken lines of each figure drawing represent structural environment and forms no part of the claim.