1. Chapter 6: Ultrasonic Instrumentation Technique
Working Stroke

2. Working Stroke Direction & Distribution
Figure 6.21a
Figure 6.21b
Figure 6.21
The ultrasonic working stroke is (a) bi-directional, such as forward and backward, and distributed equally in both directions; avoid (b) making one direction more prominent, or longer, than the other. (Length of stroke, as indicated by arrow, is exaggerated for visual ease).

3. Working Stroke Length Figure 6.22 Figure 6.22
The length of the bi-directional working stroke should not exceed 2-3 mm in total length ( mm in each direction), with even shorter strokes necessary in narrow areas or pockets.

4. Overlapping & Channeling
Figure 6.23
Figure 6.23
Overlapping pattern of the working stroke used to advance the tip in/out of the pocket and across the involved surface.
Channeling advances the tip across the treatment surface in “channels” to optimize contact of the tip with all segments of the involved surface.

5. Working Stroke Directions
Figure 6.25
Figure 6.26
Figure 6.27
Figure 6.25
Horizontal working stroke. Utilized when tip is vertically adapted on a buccal (facial) and lingual (palatal) surface.
Figure 6.26
Oblique working stroke. Utilized when tip is vertically adapted on a mesial or distal root surface.
Figure 6.27
Vertical working stroke. Utilized when tip is horizontally adapted on a mesial or distal crown surface to scale/debride the interproximal space below the contact.

6. Tapping Stroke
Figure 6.28
Tapping stroke (supragingival use only).