The ornamental design for a dental drillguidepositioningring, substantially as shown and described.
FIG. 1 is a perspective view of a dental drill guide positioning ring showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines in the figures are included for the purpose of illustrating portions of the dental drill guide positioning ring that form no part of the claimed design.