Chapter 7: Ultrasonic Instrumentation Technique Modules Transitions in Adaptation Four fundamental transitions in adaptation are made to advance the oscillating tip through a designated treatment area in a sequence that optimizes use of all surfaces of the tip, thus enabling thorough, efficient, and ergonomic instrumentation of all tooth surfaces.

Start: Point of Adaptation Figure 7.4 Figure 7.4 Lateral surface of tip vertically adapted to buccal surface. Arrow indicates horizontal stroke pattern. Starting from the primary position of vertical adaptation, a lateral surface (or when applicable, the back) of the tip is advanced across buccal and lingual surfaces using horizontal strokes.

Transition to Proximal Root Surface Figure 7.5 Figure 7.6 Transition to Proximal Root Surface: Upon reaching a line angle, vertical adaptation is maintained as the tip crosses the line angle to the proximal surface. On a mesial root surface, the back of the tip inherently adapts with this transition (Fig 7.5); on a distal root surface, the lateral surface of the tip remains adapted (Fig 7.6). The tip is then advanced across the proximal root surface using an oblique stroke pattern . Figure 7.5 Back of tip vertically adapted to mesial surface. Arrow indicates oblique stroke pattern. Figure 7.6 Lateral surface of tip vertically adapted to distal surface. Arrow indicates oblique stroke pattern

Transition to Interproximal Space Figure 7.9 Figure 7.10 Transition to Interproximal Space: As the interproximal space (or cervical embrasure) is entered, contact with the tooth is maintained while the tip is transitioned from vertical to horizontal adaptation by a slight rolling motion. On the distal aspect, the rolling motion adapts the face of the tip to the distal surface (Fig 7.9). On the mesial aspect, the back of the tip remains adapted to the mesial surface throughout this transition (Fig 7.10). It is critical that this transition occurs in the interproximal space against enamel, rather than against root structure, to avoid severe root gouging by the point of the tip during the rolling motion. Stroking of the back or face of the tip against the interproximal surface ensues in a vertical direction. Figure 7.9 Horizontal adaptation of the face of the tip to the distal surface of the crown. Arrow indicates vertical stroke pattern. Figure 7.10 Horizontal adaptation of the back of the tip to mesial surface of the crown. Arrow indicates vertical stroke pattern.

Transition to Next Tooth Figure 7.11 Transition to Next Tooth: Advancing from the mesial surface of one tooth to the next tooth in the treatment area is accomplished by maintaining horizontal orientation and bringing the face of the tip into adaptation with the distal surface of the adjacent tooth; stroke vertically against the distal surface. Figure 7.11 Instrumentation advances to the next tooth by horizontally adapting the face of the tip to the distal surface of the crown. Arrow indicates vertical stroke pattern.

Transition from Interproximal Space Figure 7.12 Figure 7.13 Transition from Interproximal Space: Contact with the tooth is maintained as the tip is transitioned from horizontal to vertical adaptation by a slight rolling motion that adapts the lateral surface of the tip to the distal surface of the tooth (Fig. 7.12). As with the transition to the interproximal space, it is critical that this transition also occurs in the interproximal space against enamel to avoid severe root gouging by the point of the tip during the rolling motion. The tip is then advanced subgingivally and stroked in an oblique direction over the distal root surface, toward the distal line angle (Fig. 7.13). Figure 7.12 Vertical adaptation of the lateral surface of the tip to the distal surface of the tooth. Figure 7.13 After transitioning to vertical adaptation in the interproximal space, the tip is advanced subgingivally to the base of the pocket. Arrow indicates oblique stroke pattern.