Mechanized instrumentation for premolar teeth involves appropriate ultrasonic insert and/or tip (UIT) selection and knowledge about crown and root anatomy.
Mechanized instrumentation for premolar teeth involves appropriate ultrasonic insert and/or tip (UIT) selection and knowledge about crown and root anatomy. Also, “technique intelligence,” or the combination of concentration, mental imagery, correct technique, and experience, should be considered for proper adaptation and activation of the UIT.
Photo Credit: EDWARDOLIVE/ISTOCK/GETTY IMAGES PLUS; LIGHTHAUNTER/ISTOCK/GETTY IMAGES PLUS
Active Tip Area
Using the appropriate active tip area is essential. The portion of the sides or back near the point is most effective for instrumentation. For magnetostrictive technology, the active tip is about 4 mm of the working end, near the point. For piezoelectric unit, the most active area is about 2 mm to 3.5 mm, depending on tip design. Adapting more than the active tip area can cause burnishing, incomplete deposit removal, and inefficient instrumentation.
Photo Credit: Kathleen O. Hodges, RDH, MS
Angle
The angle of the active tip to the root should be maintained at 0° to 15°. Because of the crown and root curvatures of premolars, 0° is nearly impossible to achieve and a 15° angle is more likely. This 15° tooth-to-tip angle is ideal because research shows that angulation greater than 15° results in loss of root substance. In fact, as the tip-to-root angle increases, so does the removal of root substance.
Photo Credit: Kathleen O. Hodges, RDH, MS
Universal Activation
The activation of UITs is not dependent on premolar teeth per se. Instead, the method for correct activation of UITs is universal for all teeth. With a sulcus or shallow pocket depth with light or moderate deposits and plaque biofilm, strokes are activated obliquely from the epithelial attachment to the gingival margin.
Photo Credit: Kathleen O. Hodges, RDH, MS
Key Takeaways
Effective ultrasonic instrumentation for these teeth depends on the clinician’s knowledge of tooth anatomy, UIT designs, and technique. Use of the active tip, a 15° tip-to-tooth angle, and various tip orientations are critical to success.