Which of the following is true about the correct adaptation of an ultrasonic working end to the tooth surface?

Question

Quizplus · Accepted Answer

Fifteen degrees is the optimum angle of the working end to the tooth surface because it does not cause undesirable surface alterations such as striations that have depth and volume. If the working end is angulated at 45 to 60 degrees, the angle between the end and the tooth is too great and undesirable root surface alterations can occur. This is the recommended angle for the curet blade to be adapted to the tooth surface when the tooth surface is smoothed (root debridement or root planing). If an ultrasonic insert or tip were adapted at a 60- to 80-degree angle, the depth of the striation and volume of the striation (stroke) it caused might be too great. This angulation is recommended for a working stroke with a curet to remove calculus deposits. It would be nearly impossible to adapt the ultrasonic working end at a zero-degree angle. In this case the working end would not be adapting to calculus itself to remove it via mechanical vibration. This statement is inaccurate. The working ends of both types of units are adapted as close to 15 degrees to the tooth as possible.

Which of the Following Is True About the Correct Adaptation