Which of the Following Is True About the Correct Adaptation

Multiple Choice

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

A) The working end is angulated at more than 45 degrees and less than 60 degrees.
B) The working end should be angulated at 15 degrees or almost parallel to the long axis of the tooth.
C) The working end is angulated at 60 degrees to 80 degrees to the tooth surface.
D) The working end is angulated at zero degrees to the tooth surface.
E) The working end is adapted at a different angle depending on if it is a piezoelectric tip or a magnetostrictive insert.