The ornamental design for the dental tool, as shown and described.
FIG. 1 is an elevated isometric view of a dental tool showing the new design, wherein a first head is at the bottom of the page and a second head is at the top of the page;
FIG. 2 is a side view of the dental tool as shown in FIG. 1, wherein the first head is at the top of the page;
FIG. 3 is a side view of the dental tool shown in FIG. 1, wherein the second head is at the top of the page;
FIG. 4 is a side view of the configuration shown in FIG. 2 rotated approximately 90 degrees;
FIG. 5 is a side view of the configuration shown in FIG. 3 rotated approximately 90 degrees;
FIG. 6 is an bottom end view (second head end) of the dental tool as shown in FIG. 1; and,
FIG. 7 is a top end view (first head end) of the dental tool as shown in FIG. 1.
The broken line showing of portions of the dental tool illustrates environmental structure and forms no part of the claimed design.