The ornamental design for a controller for dentaltreatment, as shown and described.
FIG. 1 is a front view of a controller for dental treatment;
FIG. 2 is a rear view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a perspective view from upper right side thereof; and,
FIG. 8 is a perspective view thereof, showing the state of use.
The broken lines in FIG. 8 are included for the purpose of illustrating environmental structure of the controller for dental handpiece and form no part of the claimed design.