The ornamental design for a tooth, as shown and described.
FIG. 1 is left front perspective view of a tooth showing my new design.
FIG. 2 is a front view thereof.
FIG. 3 is a bottom left front perspective view thereof.
FIG. 4 is a bottom right front perspective view thereof.
FIG. 5 is a top right front perspective view thereof.
FIG. 6 is a back left perspective view thereof.
FIG. 7 is a top left front perspective view of an alternative embodiment of the tooth of FIG. 1.
FIG. 8 is a front right perspective view thereof; and,
FIG. 9 is a back right perspective view thereof.
The broken line showing of the circular openings is included for the purpose of illustrating portions of the tooth and forms no part of the claimed design.