The ornamental design for a dentalrestorationpreform, as shown and described.
FIG. 1 is a front perspective view of a dental restoration preform showing our new design;
FIG. 2 is a back perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a back view thereof;
FIG. 6 is a left side view thereof;
FIG. 7 is a top view thereof; and,
FIG. 8 is a bottom view thereof.
The shade lines in the Figures show contour and not surface ornamentation. The broken lines in the Figures show portions of the dental restoration preform that form no part of the claimed design. The dot-dash lines showing a mandrel in the Figures is to depict environmental context only and form no part of the claimed design.